顔写真

フルカワ ヨシヒロ
古川 善博
Yoshihiro Furukawa
所属
大学院理学研究科 地学専攻 地球惑星物質科学講座
職名
准教授
学位
  • 博士(理学)(東北大学)

  • 修士(理学)(東北大学)

Researcher ID
プロフィール

初期地球や初期太陽系で起こった,生命の起源に向けた化学進化の謎を解明するために,地球科学的な知見・手法と有機化学的・分析化学的手法を組み合わせて研究を行っています.

経歴 5

  • 2020年4月 ~ 継続中
    東北大学ディスティングイッシュトリサーチャー

  • 2017年10月 ~ 継続中
    東北大学 大学院理学研究科 准教授

  • 2013年4月 ~ 2017年10月
    東北大学 大学院理学研究科 助教

  • 2014年2月 ~ 2014年5月
    Foundation for Applied Molecular Evolution 客員外国研究員

  • 2009年2月 ~ 2013年3月
    東北大学 大学院理学研究科 GCOE 助教

学歴 2

  • 東北大学 理学研究科 地学専攻

    ~ 2009年1月28日

  • 東北大学 理学部 地球物質科学科

    ~ 2004年3月25日

委員歴 4

  • Scientific Reports誌 Editorial Board Member

    2022年9月 ~ 継続中

  • 日本地球化学会 理事

    2021年10月 ~ 継続中

  • 生命の起原および進化学会 運営委員

    2020年8月 ~ 継続中

  • Geochemical Journal 副編集長

    2020年1月 ~ 継続中

所属学協会 6

  • 生命の起原および進化学会

  • 日本地球化学会

  • ISSOL The International Astrobiology Society

  • Geochemical Society

  • 日本惑星科学会

  • 日本鉱物科学会

︎全件表示 ︎最初の5件までを表示

研究キーワード 6

  • 核酸塩基

  • アミノ酸

  • 生命の起源

  • 初期太陽系

  • 初期地球

研究分野 2

  • 自然科学一般 / 地球生命科学 /

  • 自然科学一般 / 宇宙惑星科学 /

受賞 3

  1. 文部科学大臣表彰 若手科学者賞

    2017年4月 文部科学省

  2. 日本地球化学会奨励賞

    2014年9月 日本地球化学

  3. 青葉理学振興会賞

    2009年3月1日 青葉理学振興会

論文 64

  1. Boron-assisted abiotic polypeptide synthesis. 国際誌 査読有り

    Yuki Sumie, Keiichiro Sato, Takeshi Kakegawa, Yoshihiro Furukawa

    Communications Chemistry 6 (1) 89-89 2023年5月11日

    DOI: 10.1038/s42004-023-00885-7  

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    The emergence of proteins and their interactions with RNAs were a key step in the origin and early evolution of life. The abiotic synthesis of peptides has been limited in short amino acid length and is favored in highly alkaline evaporitic conditions in which RNAs are unstable. This environment is also inconsistent with estimated Hadean Earth. Prebiotic environments rich in boron are reportedly ideal for abiotic RNA synthesis. However, the effects of boron on amino acid polymerization are unclear. We report that boric acid enables the polymerization of amino acids at acidic and near-neutral pH levels based on simple heating experiments of amino acid solutions containing borate/boric acid at various pH levels. Our study provides evidence for the boron-assisted synthesis of polypeptides in prebiotically plausible environments, where the same conditions would allow for the formation of RNAs and interactions of primordial proteins and RNAs that could be inherited by RNA-dependent protein synthesis during the evolution of life.

  2. Distributions of CHN compounds in meteorites record organic syntheses in the early solar system 国際誌 査読有り

    Yoshihiro Furukawa, Daisuke Saigusa, Kuniyuki Kano, Akira Uruno, Ritsumi Saito, Motoo Ito, Megumi Matsumoto, Junken Aoki, Masayuki Yamamoto, Tomoki Nakamura

    Scientific Reports 13 (1) 6683-6683 2023年4月24日

    出版者・発行元:Springer Science and Business Media {LLC}

    DOI: 10.1038/s41598-023-33595-0  

    ISSN:2045-2322

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    <jats:title>Abstract</jats:title><jats:p>Carbonaceous meteorites contain diverse soluble organic compounds. These compounds formed in the early solar system from volatiles accreted on tiny dust particles. However, the difference in the organic synthesis on respective dust particles in the early solar system remains unclear. We found micrometer-scale heterogeneous distributions of diverse CHN<jats:sub>1-2</jats:sub> and CHN<jats:sub>1-2</jats:sub>O compounds in two primitive meteorites: the Murchison and NWA 801, using a surface-assisted laser desorption/ionization system connected to a high mass resolution mass spectrometer. These compounds contained mutual relationships of ± H<jats:sub>2</jats:sub>, ± CH<jats:sub>2</jats:sub>, ± H<jats:sub>2</jats:sub>O, and ± CH<jats:sub>2</jats:sub>O and showed highly similar distributions, indicating that they are the products of series reactions. The heterogeneity was caused by the micro-scale difference in the abundance of these compounds and the extent of the series reactions, indicating that these compounds formed on respective dust particles before asteroid accretion. The results of the present study provide evidence of heterogeneous volatile compositions and the extent of organic reactions among the dust particles that formed carbonaceous asteroids. The compositions of diverse small organic compounds associated with respective dust particles in meteorites are useful to understand different histories of volatile evolution in the early solar system. </jats:p>

  3. Synthesis of 13C-enriched amino acids with 13C-depleted insoluble organic matter in a formose-type reaction in the early solar system 査読有り

    Yoshihiro Furukawa, Yoshinari Iwasa, Yoshito Chikaraishi

    Science Advances 7 eabd3575 2021年4月

    DOI: 10.1126/sciadv.abd3575  

  4. Extraterrestrial ribose and other sugars in primitive meteorites 査読有り

    Yoshihiro Furukawa, Yoshito Chikaraishi, Naohiko Ohkouchi, Nanako O. Ogawa, Daniel P. Glavin, Jason P. Dworkin, Chiaki Abe, Tomoki Nakamura

    Proceedings of the National Academy of Sciences of UAS 116 (49) 24440-24445 2019年12月

    出版者・発行元:NATL ACAD SCIENCES

    DOI: 10.1073/pnas.1907169116  

    ISSN:0027-8424

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    Sugars are essential molecules for all terrestrial biota working in many biological processes. Ribose is particularly essential as a building block of RNA, which could have both stored information and catalyzed reactions in primitive life on Earth. Meteorites contain a number of organic compounds including key building blocks of life, i.e., amino acids, nucleobases, and phosphate. An amino acid has also been identified in a cometary sample. However, the presence of extraterrestrial bioimportant sugars remains unclear. We analyzed sugars in 3 carbonaceous chondrites and show evidence of extraterrestrial ribose and other bioessential sugars in primitive meteorites. The C-13-enriched stable carbon isotope compositions (delta C-13(vs. )VPDB) of the detected sugars show that the sugars are of extraterrestrial origin. We also conducted a laboratory simulation experiment of a potential sugar formation reaction in space. The compositions of pentoses in meteorites and the composition of the products of the laboratory simulation suggest that meteoritic sugars were formed by formose-like processes. The mineral compositions of these meteorites further suggest the formation of these sugars both before and after the accretion of their parent asteroids. Meteorites were carriers of prebiotic organic molecules to the early Earth; thus, the detection of extraterrestrial sugars in meteorites establishes the existence of natural geological routes to make and preserve them as well as raising the possibility that extraterrestrial sugars contributed to forming functional biopolymers like RNA on the early Earth or other primitive worlds.

  5. Borate and the Origin of RNA: A Model for the Precursors to Life 査読有り

    Yoshihiro Furukawa, Takeshi Kakegawa

    Elements 13 (4) 261-265 2017年8月

    出版者・発行元:MINERALOGICAL SOC AMER

    DOI: 10.2138/gselements.13.4.261  

    ISSN:1811-5209

    eISSN:1811-5217

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    According to the RNA World hypothesis, ribonucleic acid (RNA) played a critical role in the origin of life. However, ribose, an essential component of RNA, is easily degraded: finding a way to stabilize it is critical to the viability of the hypothesis. Borate has been experimentally shown to have a strong affinity for ribose, and, thus, could have protected ribose from degradation in the formose reaction, a potential process for prebiotic ribose formation. Accumulation of borate on Hadean Earth (prior to similar to 4,000 Ma) might have been a key step in the chemical evolution of the biotic sugar. Proto-arcs are suggested as a geological setting sufficiently rich in borate to stabilize ribose during the Hadean.

  6. Nucleobase and amino acid formation through impacts of meteorites on the early ocean 査読有り

    Yoshihiro Furukawa, Hiromoto Nakazawa, Toshimori Sekine, Takamichi Kobayashi, Takeshi Kakegawa

    Earth and Planetary Science Letters 429 216-222 2015年11月

    出版者・発行元:ELSEVIER

    DOI: 10.1016/j.epsl.2015.07.049  

    ISSN:0012-821X

    eISSN:1385-013X

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    The emergence of life's building blocks on the prebiotic Earth was the first crucial step for the origins of life. Extraterrestrial delivery of intact amino acids and nucleobases is the prevailing hypothesis for their availability on prebiotic Earth because of the difficulties associated with the production of these organics from terrestrial carbon and nitrogen sources under plausible prebiotic conditions. However, the variety and amounts of these intact organics delivered by meteorites would have been limited. Previous shock-recovery experiments have demonstrated that meteorite impact reactions could have generated organics on the prebiotic Earth. Here, we report on the simultaneous formation of nucleobases (cytosine and uracil) found in DNA and/or RNA, various proteinogenic amino acids (glycine, alanine, serine, aspartic acid, glutamic acid, valine, leucine, isoleucine, and proline), non-proteinogenic amino acids, and aliphatic amines in experiments simulating reactions induced by extraterrestrial objects impacting on the early oceans. To the best of our knowledge, this is the first report of the formation of nucleobases from inorganic materials by shock conditions. In these experiments, bicarbonate was used as the carbon source. Bicarbonate, which is a common dissolved carbon species in CO2-rich atmospheric conditions, was presumably the most abundant carbon species in the early oceans and in post-impact plumes. Thus, the present results expand the possibility that impact-induced reactions generated various building blocks for life on prebiotic Earth in large quantities through the use of terrestrial carbon reservoirs. (C) 2015 Elsevier B.V. All rights reserved.

  7. Abiotic Regioselective Phosphorylation of Adenosine with Borate in Formamide 査読有り

    Yoshihiro Furukawa, Hyo-Joong Kim, Daniel Hutter, Steven A. Benner

    ASTROBIOLOGY 15 (4) 259-267 2015年4月

    出版者・発行元:MARY ANN LIEBERT, INC

    DOI: 10.1089/ast.2014.1209  

    ISSN:1531-1074

    eISSN:1557-8070

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    Nearly 40 years ago, Schoffstall and his coworkers used formamide as a solvent to permit the phosphorylation of nucleosides by inorganic phosphate to give nucleoside phosphates, which (due to their thermodynamic instability with respect to hydrolysis) cannot be easily created in water by an analogous phosphorylation (the "water problem" in prebiotic chemistry). More recently, we showed that borate could stabilize certain carbohydrates against degradation (the "asphalt problem"). Here, we combine the two concepts to show that borate can work in formamide to guide the reactivity of nucleosides under conditions where they are phosphorylated. Specifically, reaction of adenosine in formamide with inorganic phosphate and pyrophosphate in the presence of borate gives adenosine-5 '-phosphate as the only detectable phosphorylated product, with formylation (as opposed to hydrolysis) being the competing reaction. Key Words: Prebiotic chemistry-Nucleoside phosphates-Phosphorylation-Borate-Formamide. Astrobiology 15, 259-267.

  8. Biomolecule formation by oceanic impacts on early Earth 査読有り

    Yoshihiro Furukawa, Toshimori Sekine, Masahiro Oba, Takeshi Kakegawa, Hiromoto Nakazawa

    Nature Geoscience 2 (1) 62-66 2009年1月

    出版者・発行元:NATURE PUBLISHING GROUP

    DOI: 10.1038/ngeo383  

    ISSN:1752-0894

    eISSN:1752-0908

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    Intense impacts of extraterrestrial objects melted the embryonic Earth, forming an inorganic body with a carbon-dioxide- and nitrogen-rich atmosphere(1,2). Certain simple organic molecules have been shown to form under conditions resembling meteorite impacts, although the link between these events and the development of more complex molecules remains unclear(3). Ordinary chondrites, the most common type of meteorite, contain solid carbon, iron and nickel-elements essential to the formation of organic chemicals(4,5). Here we use shock experiments to recreate the conditions surrounding the impact of chondritic meteorites into an early ocean. We used a propellant gun to create a high-velocity impact into a mixture of solid carbon, iron, nickel, water and nitrogen. After the impact, we recovered numerous organic molecules, including fatty acids, amines and an amino acid. We suggest that organic molecules on the early Earth may have arisen from such impact syntheses. As the natural impacts that were frequent on the early Earth are more sustained and reach higher pressures than our experiments(6,7), they may have resulted in the synthesis of a greater abundance, variety and complexity of organic compounds.

  9. Atmospheric formaldehyde production on early Mars leading to a potential formation of bio-important molecules

    Shungo Koyama, Arihiro Kamada, Yoshihiro Furukawa, Naoki Terada, Yuki Nakamura, Tatsuya Yoshida, Takeshi Kuroda, Ann Carine Vandaele

    Scientific Reports 14 (1) 2024年12月

    DOI: 10.1038/s41598-024-52718-9  

    eISSN:2045-2322

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    Formaldehyde (H2CO) is a critical precursor for the abiotic formation of biomolecules, including amino acids and sugars, which are the building blocks of proteins and RNA. Geomorphological and geochemical evidence on Mars indicates a temperate environment compatible with the existence of surface liquid water during its early history at 3.8–3.6 billion years ago (Ga), which was maintained by the warming effect of reducing gases, such as H2. However, it remains uncertain whether such a temperate and weakly reducing surface environment on early Mars was suitable for producing H2CO. In this study, we investigated the atmospheric production of H2CO on early Mars using a 1-D photochemical model assuming a thick CO2-dominated atmosphere with H2 and CO. Our results show that a continuous supply of atmospheric H2CO can be used to form various organic compounds, including amino acids and sugars. This could be a possible origin for the organic matter observed on the Martian surface. Given the previously reported conversion rate from H2CO into ribose, the calculated H2CO deposition flux suggests a continuous supply of bio-important sugars on early Mars, particularly during the Noachian and early Hesperian periods.

  10. Curation protocol of Phobos sample returned by Martian Moons eXploration

    Ryota Fukai, Tomohiro Usui, Wataru Fujiya, Yoshinori Takano, Ken‐ichi Bajo, Andrew Beck, Enrica Bonato, Nancy L. Chabot, Yoshihiro Furukawa, Hidenori Genda, Yuki Hibiya, Fred Jourdan, Thorsten Kleine, Mizuho Koike, Moe Matsuoka, Yayoi N. Miura, Frédéric Moynier, Ryuji Okazaki, Sara S. Russell, Hirochika Sumino, Michael E. Zolensky, Haruna Sugahara, Shogo Tachibana, Kanako Sakamoto, Masanao Abe, Yuichiro Cho, Kiyoshi Kuramoto

    Meteoritics and Planetary Science 2024年1月11日

    出版者・発行元:Wiley

    DOI: 10.1111/maps.14121  

    ISSN:1086-9379

    eISSN:1945-5100

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    Abstract Japan Aerospace Exploration Agency's Martian Moons eXploration (MMX) mission will launch a spacecraft in 2024 to return samples from Phobos in 2029. Curatorial work for the returned Phobos samples is critical for the sample allocation without degrading the sample integrity and subsequent sample analysis that will provide new constraints on the origin of Phobos and the evolution of the circum‐Mars environment. The Sample Analysis Working Team of the MMX is designing the sample curation protocol. The curation protocol consists of three phases: (1) quick analysis (extraction and mass spectrometry for gases), (2) pre‐basic characterization (bulk‐scale observation), and (3) basic characterization (grain‐by‐grain observation and allocation of the sample aliquots). Nondestructive analyses within the clean chamber (e.g., visible and near‐infrared spectral imaging) and outside the chamber (e.g., gas mass spectrometry) are incorporated into the curation flow in coordination with the MMX mission instrument teams for ground‐truthing the remote‐sensing data sets. The MMX curation/sample analysis flow enables the seamless integration between the sample and remote‐sensing data sets to maximize the scientific value of the collected Phobos samples.

  11. Hexose phosphorylation for a non-enzymatic glycolysis and pentose phosphate pathway on early Earth

    Yuta Hirakawa, Takeshi Kakegawa, Yoshihiro Furukawa

    Scientific Reports 14 (1) 2024年1月2日

    出版者・発行元:Springer Science and Business Media LLC

    DOI: 10.1038/s41598-023-50743-8  

    eISSN:2045-2322

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    Abstract Glycolysis and pentose phosphate pathways play essential roles in cellular processes and are assumed to be among the most ancient metabolic pathways. Non-enzymatic metabolism-like reactions might have occurred on the prebiotic Earth and been inherited by the biological reactions. Previous research has identified a part of the non-enzymatic glycolysis and the non-enzymatic pentose phosphate pathway from glucose 6-phosphate and 6-phosphogluconate, which are intermediates of these reactions. However, how these phosphorylated molecules were formed on the prebiotic Earth remains unclear. Herein, we demonstrate the synthesis of glucose and gluconate from simple aldehydes in alkaline solutions and the formation of glucose 6-phosphate and 6-phosphogluconate with borate using thermal evaporation. These results imply that the initial stages of glycolysis-like and pentose phosphate pathway-like reactions were achieved in borate-rich evaporative environments on prebiotic Earth, suggesting that non-enzymatic metabolism provided biomolecules and their precursors on prebiotic Earth.

  12. Quantification of bulk elemental composition for C-type asteroid Ryugu samples with nondestructive elemental analysis using muon beam

    Kazuhiko Ninomiya, Takahito Osawa, Kentaro Terada, Taiga Wada, Shunsaku Nagasawa, I. Haun Chiu, Tomoki Nakamura, Tadayuki Takahashi, Yasuhiro Miyake, M. Kenya Kubo, Soshi Takeshita, Akihiro Taniguchi, Izumi Umegaki, Shin Watanabe, Toshiyuki Azuma, Miho Katsuragawa, Takahiro Minami, Kazumi Mizumoto, Koichiro Shimomura, Shin'ichiro Takeda, Tomoyo Morita, Mizuha Kikuiri, Kana Amano, Eiichi Kagawa, Yoshihiro Furukawa, Hisayoshi Yurimoto, Takaaki Noguchi, Ryuji Okazaki, Hikaru Yabuta, Hiroshi Naraoka, Kanako Sakamoto, Shogo Tachibana, Toru Yada, Masahiro Nishimura, Aiko Nakato, Akiko Miyazaki, Kasumi Yogata, Masanao Abe, Tatsuaki Okada, Tomohiro Usui, Makoto Yoshikawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Satoru Nakazawa, Sei ichiro Watanabe, Yuichi Tsuda

    Meteoritics and Planetary Science 2024年

    DOI: 10.1111/maps.14135  

    ISSN:1086-9379

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    Samples from asteroid Ryugu, brought back by asteroid explorer Hayabusa2, are important for investigating the origin and evolution of the solar system. Here, we report the elemental compositions of a 123-mg Ryugu sample determined with a nondestructive muon elemental analysis method. This method is a powerful tool for determining bulk chemical composition, including light elements such as C, N, and O. From the muonic x-ray spectra with three carbonaceous chondrites, the relationship between the elemental composition and muonic x-ray intensity was determined for each element. Calibration curves showed linearity, and the elemental composition of Ryugu was quantitatively determined. The results reflect the average bulk elemental composition of asteroid Ryugu owing to the large amount of samples. Ryugu has an elemental composition similar to that of Orgueil (CI1) and should be classified as CI1. However, the O/Si ratio of Ryugu is 25% lower than that of Orgueil, indicating that Orgueil may have been seriously contaminated by terrestrial materials after its fall to Earth. These results indicate that the Ryugu sample is more representative than the CI chondrites as a solid material of the solar system.

  13. Investigating the impact of x-ray computed tomography imaging on soluble organic matter in the Murchison meteorite: Implications for Bennu sample analyses

    Daniel P. Glavin, Scott A. Eckley, José C. Aponte, Eve L. Berger, Aaron S. Burton, Jason P. Dworkin, Jamie E. Elsila, Frank T. Ferguson, Yoshihiro Furukawa, Heather V. Graham, Toshiki Koga, Michael Liss, Hannah L. McLain, Hiroshi Naraoka, Yasuhiro Oba, Eric T. Parker, Kevin Righter, Philippe Schmitt-Kopplin, Danielle N. Simkus, Yoshinori Takano, Harold C. Connolly, Dante S. Lauretta

    Meteoritics and Planetary Science 59 (1) 105-133 2024年1月

    DOI: 10.1111/maps.14111  

    ISSN:1086-9379

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    X-ray computed tomography (XCT) is a valuable reconnaissance tool for three-dimensional imaging and identification of distinct lithologies in extraterrestrial samples. It will be used as part of the preliminary examination of samples returned from asteroid (101955) Bennu by the Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) mission. However, it must first be established whether x-rays generated during XCT could degrade or alter the organic composition of the returned samples by radiolysis. To test this, we split a crushed sample of the Murchison CM2 meteorite, kept one portion as a control, and irradiated the other portion up to the maximum x-ray dosage (~180 Gy) that a Bennu sample would experience during an XCT imaging experiment. We then extracted organic compounds from both splits and conducted (i) nontargeted soluble organic analyses to compare the chemical distributions of C-, H-, O-, N-, and S-bearing species and (ii) targeted measurements to quantify the abundances of 96 individual soluble organic molecules that included protein amino acids, amines, carboxylic acids, hydroxy acids, carbonyl compounds, polycyclic aromatic hydrocarbons, alcohols, sugars, and N-heterocycles. We found that XCT imaging of the Murchison meteorite had no measurable impact on the relative abundances or enantiomeric compositions of most of the soluble organic compounds targeted in this study. Elevated total abundances of several soluble organic compound classes were observed in the XCT-scanned Murchison sample relative to the control. This is likely related to particle size heterogeneity and specific surface area differences between the sample aliquots used for the extractions, rather than a result of the x-ray exposure. Assuming the samples returned from asteroid Bennu by OSIRIS-REx have a similar composition to carbonaceous chondrites, these data provide confidence that XCT will not significantly alter their soluble organic compositions.

  14. Reassigning CI chondrite parent bodies based on reflectance spectroscopy of samples from carbonaceous asteroid Ryugu and meteorites

    Kana Amano, Moe Matsuoka, Tomoki Nakamura, Eiichi Kagawa, Yuri Fujioka, Sandra M. Potin, Takahiro Hiroi, Eri Tatsumi, Ralph E. Milliken, Eric Quirico, Pierre Beck, Rosario Brunetto, Masayuki Uesugi, Yoshio Takahashi, Takahiro Kawai, Shohei Yamashita, Yuma Enokido, Taiga Wada, Yoshihiro Furukawa, Michael E. Zolensky, Driss Takir, Deborah L. Domingue, Camilo Jaramillo-Correa, Faith Vilas, Amanda R. Hendrix, Mizuha Kikuiri, Tomoyo Morita, Hisayoshi Yurimoto, Takaaki Noguchi, Ryuji Okazaki, Hikaru Yabuta, Hiroshi Naraoka, Kanako Sakamoto, Shogo Tachibana, Toru Yada, Masahiro Nishimura, Aiko Nakato, Akiko Miyazaki, Kasumi Yogata, Masanao Abe, Tatsuaki Okada, Tomohiro Usui, Makoto Yoshikawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Satoru Nakazawa, Sei-ichiro Watanabe, Yuichi Tsuda

    Science Advances 9 (49) 2023年12月8日

    出版者・発行元:American Association for the Advancement of Science (AAAS)

    DOI: 10.1126/sciadv.adi3789  

    eISSN:2375-2548

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    The carbonaceous asteroid Ryugu has been explored by the Hayabusa2 spacecraft to elucidate the actual nature of hydrous asteroids. Laboratory analyses revealed that the samples from Ryugu are comparable to unheated CI carbonaceous chondrites; however, reflectance spectra of Ryugu samples and CIs do not coincide. Here, we demonstrate that Ryugu sample spectra are reproduced by heating Orgueil CI chondrite at 300°C under reducing conditions, which caused dehydration of terrestrial weathering products and reduction of iron in phyllosilicates. Terrestrial weathering of CIs accounts for the spectral differences between Ryugu sample and CIs, which is more severe than space weathering that likely explains those between asteroid Ryugu and the collected samples. Previous assignments of CI chondrite parent bodies, i.e., chemically most primitive objects in the solar system, are based on the spectra of CI chondrites. This study indicates that actual spectra of CI parent bodies are much darker and flatter at ultraviolet to visible wavelengths than the spectra of CI chondrites.

  15. Polycyclic aromatic hydrocarbons in samples of Ryugu formed in the interstellar medium

    Sarah S. Zeichner, José C. Aponte, Surjyendu Bhattacharjee, Guannan Dong, Amy E. Hofmann, Jason P. Dworkin, Daniel P. Glavin, Jamie E. Elsila, Heather V. Graham, Hiroshi Naraoka, Yoshinori Takano, Shogo Tachibana, Allison T. Karp, Kliti Grice, Alex I. Holman, Katherine H. Freeman, Hisayoshi Yurimoto, Tomoki Nakamura, Takaaki Noguchi, Ryuji Okazaki, Hikaru Yabuta, Kanako Sakamoto, Toru Yada, Masahiro Nishimura, Aiko Nakato, Akiko Miyazaki, Kasumi Yogata, Masanao Abe, Tatsuaki Okada, Tomohiro Usui, Makoto Yoshikawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Satoru Nakazawa, Sei Ichiro Watanabe, Yuichi Tsuda, Kenji Hamase, Kazuhiko Fukushima, Dan Aoki, Minako Hashiguchi, Hajime Mita, Yoshito Chikaraishi, Naohiko Ohkouchi, Nanako O. Ogawa, Saburo Sakai, Eric T. Parker, Hannah L. McLain, Francois Regis Orthous-Daunay, Véronique Vuitton, Cédric Wolters, Philippe Schmitt-Kopplin, Norbert Hertkorn, Roland Thissen, Alexander Ruf, Junko Isa, Yasuhiro Oba, Toshiki Koga, Toshihiro Yoshimura, Daisuke Araoka, Haruna Sugahara, Aogu Furusho, Yoshihiro Furukawa, Junken Aoki, Kuniyuki Kano, Shin Ichiro M. Nomura, Kazunori Sasaki, Hajime Sato, Takaaki Yoshikawa, Satoru Tanaka, Mayu Morita, Morihiko Onose, Fumie Kabashima, Kosuke Fujishima, Tomoya Yamazaki, Yuki Kimura, John M. Eiler

    Science 382 (6677) 1411-1416 2023年12月1日

    DOI: 10.1126/science.adg6304  

    ISSN:0036-8075

    eISSN:1095-9203

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    Polycyclic aromatic hydrocarbons (PAHs) contain ≲20% of the carbon in the interstellar medium. They are potentially produced in circumstellar environments (at temperatures ≳1000 kelvin), by reactions within cold (~10 kelvin) interstellar clouds, or by processing of carbon-rich dust grains. We report isotopic properties of PAHs extracted from samples of the asteroid Ryugu and the meteorite Murchison. The doubly-13C substituted compositions (D2×13C values) of the PAHs naphthalene, fluoranthene, and pyrene are 9 to 51% higher than values expected for a stochastic distribution of isotopes. The D2×13C values are higher than expected if the PAHs formed in a circumstellar environment, but consistent with formation in the interstellar medium. By contrast, the PAHs phenanthrene and anthracene in Ryugu samples have D2×13C values consistent with formation by higher-temperature reactions.

  16. Soluble organic matter Molecular atlas of Ryugu reveals cold hydrothermalism on C-type asteroid parent body

    Philippe Schmitt-Kopplin, Norbert Hertkorn, Mourad Harir, Franco Moritz, Marianna Lucio, Lydie Bonal, Eric Quirico, Yoshinori Takano, Jason P. Dworkin, Hiroshi Naraoka, Shogo Tachibana, Tomoki Nakamura, Takaaki Noguchi, Ryuji Okazaki, Hikaru Yabuta, Hisayoshi Yurimoto, Kanako Sakamoto, Toru Yada, Masahiro Nishimura, Aiko Nakato, Akiko Miyazaki, Kasumi Yogata, Masanao Abe, Tomohiro Usui, Makoto Yoshikawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Satoru Nakazawa, Tatsuaki Okada, Sei-ichiro Watanabe, Yuichi Tsuda, Kenji Hamase, Aogu Furusho, Minako Hashiguchi, Kazuhiko Fukushima, Dan Aoki, José C. Aponte, Eric T. Parker, Daniel P. Glavin, Hannah L. McLain, Jamie E. Elsila, Heather V. Graham, John M. Eiler, Alexander Ruf, Francois-Regis Orthous-Daunay, Junko Isa, Véronique Vuitton, Roland Thissen, Nanako O. Ogawa, Saburo Sakai, Toshihiro Yoshimura, Toshiki Koga, Haruna Sugahara, Naohiko Ohkouchi, Hajime Mita, Yoshihiro Furukawa, Yasuhiro Oba

    Nature Communications 14 (1) 2023年10月16日

    出版者・発行元:Springer Science and Business Media LLC

    DOI: 10.1038/s41467-023-42075-y  

    eISSN:2041-1723

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    Abstract The sample from the near-Earth carbonaceous asteroid (162173) Ryugu is analyzed in the context of carbonaceous meteorites soluble organic matter. The analysis of soluble molecules of samples collected by the Hayabusa2 spacecraft shines light on an extremely high molecular diversity on the C-type asteroid. Sequential solvent extracts of increasing polarity of Ryugu samples are analyzed using mass spectrometry with complementary ionization methods and structural information confirmed by nuclear magnetic resonance spectroscopy. Here we show a continuum in the molecular size and polarity, and no organomagnesium molecules are detected, reflecting a low temperature and water-rich environment on the parent body approving earlier mineralogical and chemical data. High abundance of sulfidic and nitrogen rich compounds as well as high abundance of ammonium ions confirm the water processing. Polycyclic aromatic hydrocarbons are also detected in a structural continuum of carbon saturations and oxidations, implying multiple origins of the observed organic complexity, thus involving generic processes such as earlier carbonization and serpentinization with successive low temperature aqueous alteration.

  17. Micro-impact-induced mechano-chemical synthesis of organic precursors from FeC/FeN and carbonates/nitrates in water and its extension to nucleobases

    Koichi Kugimiya, Kenji Asai, Takashi Harada, Yoshihiro Furukawa, Makio Naito

    GREEN PROCESSING AND SYNTHESIS 12 (1) 2023年6月

    出版者・発行元:DE GRUYTER POLAND SP Z O O

    DOI: 10.1515/gps-2023-0020  

    ISSN:2191-9542

    eISSN:2191-9550

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    Much effort was taken to elucidate how organic precursors appeared in early Earth, and attention was paid to two impact experiments: hypervelocity impacts by a propellant gun which simulated meteorite collides to Earth forming fatty acids and amino acids from inorganics, and micro-impacts by a planetary ball-mill which formed ammonium and acetic acid from inorganics. Our extended study on micro- impacts showed the formation of carboxylic acids, amines, and amino acids from Fe3C/Fe4N, carbon, and carbonates/nitrates by milling up to 30 h at 40 G. Fe(CO2) 2 center dot 2H(2)O accelerated the formation a step further. Cu addition caused superior capability to form amines and amino acids. Two reaction fields were disclosed. In the impact field, the hydration of ferrous materials generated hydrogen which hydrogenated inorganic carbons to organics and ferrous transient materials and, in the maturing field, hydrogenated materials were then transformed into complex organics. Iron and CO2 were presumably the key components in the Hadean Ocean. Discussions on the mechano-chemical reaction were extended to serpentinization coupled with diastrophism of oceanic crusts and further led to a depiction that organic precursors were formed by micro-impacts and frictions of rocks and sands (like milling-balls) due to tremors in crusts. It provides a new path on how organic precursors were formed on the aqua-planet Earth.

  18. The spatial distribution of soluble organic matter and their relationship to minerals in the asteroid (162173) Ryugu

    Minako Hashiguchi, Dan Aoki, Kazuhiko Fukushima, Hiroshi Naraoka, Yoshinori Takano, Jason P. Dworkin, Karin E. Dworkin, José C. Aponte, Jamie E. Elsila, John M. Eiler, Yoshihiro Furukawa, Aogu Furusho, Daniel P. Glavin, Heather V. Graham, Kenji Hamase, Norbert Hertkorn, Junko Isa, Toshiki Koga, Hannah L. McLain, Hajime Mita, Yasuhiro Oba, Nanako O. Ogawa, Naohiko Ohkouchi, Francois-Regis Orthous-Daunay, Eric T. Parker, Alexander Ruf, Saburo Sakai, Philippe Schmitt-Kopplin, Haruna Sugahara, Roland Thissen, Véronique Vuitton, Cédric Wolters, Toshihiro Yoshimura, Hisayoshi Yurimoto, Tomoki Nakamura, Takaaki Noguchi, Ryuji Okazaki, Hikaru Yabuta, Kanako Sakamoto, Shogo Tachibana, Toru Yada, Masahiro Nishimura, Aiko Nakato, Akiko Miyazaki, Kasumi Yogata, Masanao Abe, Tomohiro Usui, Makoto Yoshikawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Satoru Nakazawa, Sei-ichiro Watanabe, Yuichi Tsuda

    Earth, Planets and Space 75 (1) 2023年5月8日

    出版者・発行元:Springer Science and Business Media LLC

    DOI: 10.1186/s40623-023-01792-w  

    eISSN:1880-5981

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    Abstract We performed in-situ analysis on a ~ 1 mm-sized grain A0080 returned by the Hayabusa2 spacecraft from near-Earth asteroid (162173) Ryugu to investigate the relationship of soluble organic matter (SOM) to minerals. Desorption electrospray ionization-high resolution mass spectrometry (DESI-HRMS) imaging mapped more than 200 CHN, CHO, CHO–Na (sodium adducted), and CHNO soluble organic compounds. A heterogeneous spatial distribution was observed for different compound classes of SOM as well as among alkylated homologues on the sample surface. The A0080 sample showed mineralogy more like an Ivuna-type (CI) carbonaceous chondrite than other meteorites. It contained two different lithologies, which are either rich (lithology 1) or poor (lithology 2) in magnetite, pyrrhotite, and dolomite. CHN compounds were more concentrated in lithology 1 than in lithology 2; on the other hand, CHO, CHO–Na, and CHNO compounds were distributed in both lithologies. Such different spatial distribution of SOM is likely the result of interaction of the SOM with minerals, during precipitation of the SOM via fluid activity, or could be due to difference in transportation efficiencies of SOMs in aqueous fluid. Organic-related ions measured by time-of-flight secondary ion mass spectrometry (ToF–SIMS) did not coincide with the spatial distribution revealed by DESI-HRMS imaging. This result may be because the different ionization mechanism between DESI and SIMS, or indicate that the ToF–SIMS data would be mainly derived from methanol-insoluble organic matter in A0080. In the Orgueil meteorite, such relationship between altered minerals and SOM distributions was not observed by DESI-HRMS analysis and field-emission scanning electron microscopy, which would result from differences of SOM formation processes and sequent alteration process on the parent bodies or even on the Earth. Alkylated homologues of CHN compounds were identified in A0080 by DESI-HRMS imaging as observed in the Murchison meteorite, but not from the Orgueil meteorite. These compounds with a large C number were enriched in Murchison fragments with abundant carbonate grains. In contrast, such relationship was not observed in A0080, implying different formation or growth mechanisms for the alkylated CHN compounds by interaction with fluid and minerals on the Murchison parent body and asteroid Ryugu. Graphical Abstract

  19. Evidence for Solution-Mediated Phase Transitions in Kidney Stones: Phase Transition Exacerbates Kidney Stone Disease

    Mihoko Maruyama, Yutaro Tanaka, Koichi Momma, Yoshihiro Furukawa, Hiroshi Y. Yoshikawa, Rie Tajiri, Masanori Nakamura, Kazumi Taguchi, Shuzo Hamamoto, Ryosuke Ando, Katsuo Tsukamoto, Kazufumi Takano, Masayuki Imanishi, Shigeyoshi Usami, Kenjiro Kohri, Atsushi Okada, Takahiro Yasui, Masashi Yoshimura, Yusuke Mori

    Crystal Growth & Design 2023年4月

    出版者・発行元:American Chemical Society ({ACS})

    DOI: 10.1021/acs.cgd.3c00108  

    ISSN:1528-7483

  20. Quantitative analysis of calcium oxalate monohydrate and dihydrate for elucidating the formation mechanism of calcium oxalate kidney stones

    Mihoko Maruyama, Koichi P. Sawada, Yutaro Tanaka, Atsushi Okada, Koichi Momma, Masanori Nakamura, Ryota Mori, Yoshihiro Furukawa, Yuki Sugiura, Rie Tajiri, Kazumi Taguchi, Shuzo Hamamoto, Ryosuke Ando, Katsuo Tsukamoto, Kazufumi Takano, Masayuki Imanishi, Masashi Yoshimura, Takahiro Yasui, Yusuke Mori

    PLOS ONE 18 (3) e0282743-e0282743 2023年3月9日

    出版者・発行元:Public Library of Science (PLoS)

    DOI: 10.1371/journal.pone.0282743  

    eISSN:1932-6203

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    We sought to identify and quantitatively analyze calcium oxalate (CaOx) kidney stones on the order of micrometers, with a focus on the quantitative identification of calcium oxalate monohydrate (COM) and dihydrate (COD). We performed Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (PXRD), and microfocus X-ray computed tomography measurements (microfocus X-ray CT) and compared their results. An extended analysis of the FTIR spectrum focusing on the 780 cm<sup>−1</sup> peak made it possible to achieve a reliable analysis of the COM/COD ratio. We succeeded in the quantitative analysis of COM/COD in 50-μm<sup>2</sup> areas by applying microscopic FTIR for thin sections of kidney stones, and by applying microfocus X-ray CT system for bulk samples. The analysis results based on the PXRD measurements with micro-sampling, the microscopic FTIR analysis of thin sections, and the microfocus X-ray CT system observation of a bulk kidney stone sample showed roughly consistent results, indicating that all three methods can be used complementarily. This quantitative analysis method evaluates the detailed CaOx composition on the preserved stone surface and provides information on the stone formation processes. This information clarifies where and which crystal phase nucleates, how the crystals grow, and how the transition from the metastable phase to the stable phase proceeds. The phase transition affects the growth rate and hardness of kidney stones and thus provides crucial clues to the kidney stone formation process.

  21. Soluble organic molecules in samples of the carbonaceous asteroid (162173) Ryugu

    Hiroshi Naraoka, Yoshinori Takano, Jason P. Dworkin, Yasuhiro Oba, Kenji Hamase, Aogu Furusho, Nanako O. Ogawa, Minako Hashiguchi, Kazuhiko Fukushima, Dan Aoki, Philippe Schmitt-Kopplin, José C. Aponte, Eric T. Parker, Daniel P. Glavin, Hannah L. McLain, Jamie E. Elsila, Heather V. Graham, John M. Eiler, Francois Regis Orthous-Daunay, Cédric Wolters, Junko Isa, Véronique Vuitton, Roland Thissen, Saburo Sakai, Toshihiro Yoshimura, Toshiki Koga, Naohiko Ohkouchi, Yoshito Chikaraishi, Haruna Sugahara, Hajime Mita, Yoshihiro Furukawa, Norbert Hertkorn, Alexander Ruf, Hisayoshi Yurimoto, Tomoki Nakamura, Takaaki Noguchi, Ryuji Okazaki, Hikaru Yabuta, Kanako Sakamoto, Shogo Tachibana, Harold C. Connolly, Dante S. Lauretta, Masanao Abe, Toru Yada, Masahiro Nishimura, Kasumi Yogata, Aiko Nakato, Miwa Yoshitake, Ayako Suzuki, Akiko Miyazaki, Shizuho Furuya, Kentaro Hatakeda, Hiromichi Soejima, Yuya Hitomi, Kazuya Kumagai, Tomohiro Usui, Tasuku Hayashi, Daiki Yamamoto, Ryota Fukai, Kohei Kitazato, Seiji Sugita, Noriyuki Namiki, Masahiko Arakawa, Hitoshi Ikeda, Masateru Ishiguro, Naru Hirata, Koji Wada, Yoshiaki Ishihara, Rina Noguchi, Tomokatsu Morota, Naoya Sakatani, Koji Matsumoto, Hiroki Senshu, Rie Honda, Eri Tatsumi, Yasuhiro Yokota, Chikatoshi Honda, Tatsuhiro Michikami, Moe Matsuoka, Akira Miura, Hirotomo Noda, Tetsuya Yamada, Keisuke Yoshihara, Kosuke Kawahara, Masanobu Ozaki, Yu Ichi Iijima, Hajime Yano, Masahiko Hayakawa, Takahiro Iwata, Ryudo Tsukizaki, Hirotaka Sawada, Satoshi Hosoda, Kazunori Ogawa, Chisato Okamoto, Naoyuki Hirata, Kei Shirai, Yuri Shimaki, Manabu Yamada, Tatsuaki Okada, Yukio Yamamoto

    Science 379 (6634) 2023年2月24日

    DOI: 10.1126/science.abn9033  

    ISSN:0036-8075

    eISSN:1095-9203

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    The Hayabusa2 spacecraft collected samples from the surface of the carbonaceous near-Earth asteroid (162173) Ryugu and brought them to Earth. The samples were expected to contain organic molecules, which record processes that occurred in the early Solar System. We analyzed organic molecules extracted from the Ryugu surface samples. We identified a variety of molecules containing the atoms CHNOS, formed by methylation, hydration, hydroxylation, and sulfurization reactions. Amino acids, aliphatic amines, carboxylic acids, polycyclic aromatic hydrocarbons, and nitrogen-heterocyclic compounds were detected, which had properties consistent with an abiotic origin. These compounds likely arose from an aqueous reaction on Ryugu’s parent body and are similar to the organics in Ivuna-type meteorites. These molecules can survive on the surfaces of asteroids and be transported throughout the Solar System.

  22. Abiotic formation of ribose 5'-phosphate from ribose and apatite with carbonate- and formate-rich solutions

    Masaya Takabayashi, Yuta Hirakawa, Takeshi Kakegawa, Yoshihiro Furukawa

    GEOCHEMICAL JOURNAL 57 (5) 134-142 2023年

    出版者・発行元:Geochemical Society of Japan

    DOI: 10.2343/geochemj.gj23012  

    ISSN:0016-7002

    eISSN:1880-5973

  23. Borate-guided ribose phosphorylation for prebiotic nucleotide synthesis 査読有り

    Yuta Hirakawa, Takeshi Kakegawa, Yoshihiro Furukawa

    Scientific Reports 12 (1) 2022年12月

    出版者・発行元:Springer Science and Business Media {LLC}

    DOI: 10.1038/s41598-022-15753-y  

    ISSN:2045-2322

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    <jats:title>Abstract</jats:title><jats:p>Polymers of ribonucleotides (RNAs) are considered to store genetic information and promote biocatalytic reactions for the proto life on chemical evolution. Abiotic synthesis of ribonucleotide was successful in past experiments; nucleoside synthesis occurred first, followed by phosphorylation. These abiotic syntheses are far from biotic reactions and have difficulties as a prebiotic reaction in reacting chemicals in a specific order and purifying intermediates from other molecules in multi-steps of reactions. Another reaction, ribose phosphorylation followed by nucleobase synthesis or nucleobase addition, is close to the biotic reactions of nucleotide synthesis. However, the synthesis of ribose 5′-phosphate under prebiotically plausible conditions remains unclear. Here, we report a high-yield regioselective one-pot synthesis of ribose 5′-phosphate from an aqueous solution containing ribose, phosphate, urea, and borate by simple thermal evaporation. Of note, phosphorylation of ribose before the nucleoside formation differs from the traditional prebiotic nucleotide syntheses and is also consistent with biological nucleotide synthesis. Phosphorylation occurred to the greatest extent in ribose compared to other aldopentoses, only in the presence of borate. Borate is known to improve the stability of ribose preferentially. Geological evidence suggests the presence of borate-rich settings on the early Earth. Therefore, borate-rich evaporitic environments could have facilitated preferential synthesis of ribonucleotide coupled with enhanced stability of ribose on the early Earth.</jats:p>

  24. Identifying the wide diversity of extraterrestrial purine and pyrimidine nucleobases in carbonaceous meteorites

    Yasuhiro Oba, Yoshinori Takano, Yoshihiro Furukawa, Toshiki Koga, Daniel P. Glavin, Jason P. Dworkin, Hiroshi Naraoka

    Nature Communications 13 (1) 2022年12月

    出版者・発行元:Springer Science and Business Media LLC

    DOI: 10.1038/s41467-022-29612-x  

    eISSN:2041-1723

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    Abstract The lack of pyrimidine diversity in meteorites remains a mystery since prebiotic chemical models and laboratory experiments have predicted that these compounds can also be produced from chemical precursors found in meteorites. Here we report the detection of nucleobases in three carbonaceous meteorites using state-of-the-art analytical techniques optimized for small-scale quantification of nucleobases down to the range of parts per trillion (ppt). In addition to previously detected purine nucleobases in meteorites such as guanine and adenine, we identify various pyrimidine nucleobases such as cytosine, uracil, and thymine, and their structural isomers such as isocytosine, imidazole-4-carboxylic acid, and 6-methyluracil, respectively. Given the similarity in the molecular distribution of pyrimidines in meteorites and those in photon-processed interstellar ice analogues, some of these derivatives could have been generated by photochemical reactions prevailing in the interstellar medium and later incorporated into asteroids during solar system formation. This study demonstrates that a diversity of meteoritic nucleobases could serve as building blocks of DNA and RNA on the early Earth.

  25. Multicolor imaging of calcium-binding proteins in human kidney stones for elucidating the effects of proteins on crystal growth. 国際誌

    Yutaro Tanaka, Mihoko Maruyama, Atsushi Okada, Yoshihiro Furukawa, Koichi Momma, Yuki Sugiura, Rie Tajiri, Koichi P Sawada, Shunichi Tanaka, Kazufumi Takano, Kazumi Taguchi, Shuzo Hamamoto, Ryosuke Ando, Katsuo Tsukamoto, Masashi Yoshimura, Yusuke Mori, Takahiro Yasui

    Scientific Reports 11 (1) 16841-16841 2021年8月26日

    出版者・発行元:NATURE PORTFOLIO

    DOI: 10.1038/s41598-021-95782-1  

    ISSN:2045-2322

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    The pathogenesis of kidney stone formation includes multi-step processes involving complex interactions between mineral components and protein matrix. Calcium-binding proteins in kidney stones have great influences on the stone formation. The spatial distributions of these proteins in kidney stones are essential for evaluating the in vivo effects of proteins on the stone formation, although the actual distribution of these proteins is still unclear. We reveal micro-scale distributions of three different proteins, namely osteopontin (OPN), renal prothrombin fragment 1 (RPTF-1), and calgranulin A (Cal-A), in human kidney stones retaining original mineral phases and textures: calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD). OPN and RPTF-1 were distributed inside of both COM and COD crystals, whereas Cal-A was distributed outside of crystals. OPN and RPTF-1 showed homogeneous distributions in COM crystals with mosaic texture, and periodically distributions parallel to specific crystal faces in COD crystals. The unique distributions of these proteins enable us to interpret the different in vivo effects of each protein on CaOx crystal growth based on their physico-chemical properties and the complex physical environment changes of each protein. This method will further allow us to elucidate in vivo effects of different proteins on kidney stone formation.

  26. Analytical protocols for Phobos regolith samples returned by the Martian Moons eXploration (MMX) mission

    Wataru Fujiya, Yoshihiro Furukawa, Haruna Sugahara, Mizuho Koike, Ken-ichi Bajo, Nancy L. Chabot, Yayoi N. Miura, Frederic Moynier, Sara S. Russell, Shogo Tachibana, Yoshinori Takano, Tomohiro Usui, Michael E. Zolensky

    EARTH PLANETS AND SPACE 73 (1) 2021年6月

    出版者・発行元:SPRINGER

    DOI: 10.1186/s40623-021-01438-9  

    eISSN:1880-5981

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    Japan Aerospace Exploration Agency (JAXA) will launch a spacecraft in 2024 for a sample return mission from Phobos (Martian Moons eXploration: MMX). Touchdown operations are planned to be performed twice at different landing sites on the Phobos surface to collect > 10 g of the Phobos surface materials with coring and pneumatic sampling systems on board. The Sample Analysis Working Team (SAWT) of MMX is now designing analytical protocols of the returned Phobos samples to shed light on the origin of the Martian moons as well as the evolution of the Mars-moon system. Observations of petrology and mineralogy, and measurements of bulk chemical compositions and stable isotopic ratios of, e.g., O, Cr, Ti, and Zn can provide crucial information about the origin of Phobos. If Phobos is a captured asteroid composed of primitive chondritic materials, as inferred from its reflectance spectra, geochemical data including the nature of organic matter as well as bulk H and N isotopic compositions characterize the volatile materials in the samples and constrain the type of the captured asteroid. Cosmogenic and solar wind components, most pronounced in noble gas isotopic compositions, can reveal surface processes on Phobos. Long- and short-lived radionuclide chronometry such as Mn-53-Cr-53 and Rb-87-Sr-87 systematics can date pivotal events like impacts, thermal metamorphism, and aqueous alteration on Phobos. It should be noted that the Phobos regolith is expected to contain a small amount of materials delivered from Mars, which may be physically and chemically different from any Martian meteorites in our collection and thus are particularly precious. The analysis plan will be designed to detect such Martian materials, if any, from the returned samples dominated by the endogenous Phobos materials in curation procedures at JAXA before they are processed for further analyses.

  27. Experimental Investigation of the Formation of Formaldehyde by Hadean and Noachian Impacts 査読有り

    Saeka Masuda, Yoshihiro Furukawa, Takamichi Kobayashi, Toshimori Sekine, Takeshi Kakegawa

    ASTROBIOLOGY 21 (4) 413-420 2021年4月

    出版者・発行元:MARY ANN LIEBERT, INC

    DOI: 10.1089/ast.2020.2320  

    ISSN:1531-1074

    eISSN:1557-8070

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    Formaldehyde (FA) is an important precursor in the abiotic synthesis of major biomolecules including amino acids, sugars, and nucleobases. Thus, spontaneous formation of prebiotic FA must have been crucial for the chemical origin of life. The frequent impacts of meteorites and asteroids on Hadean Earth have been considered one of the abiotic synthetic processes of organic compounds. However, the impact-induced formation of FA from CO2 as the major atmospheric constituent has not been confirmed yet. This study investigated the formation of FA in impact-induced reactions among meteoritic minerals, bicarbonate, gaseous nitrogen, and water to simulate the abiotic process experimentally. Products were analyzed with ultra-high-performance liquid chromatography/tandem mass spectrometry and powder X-ray diffraction techniques. The results show the formation of FA and oxidation of metallic iron to siderite in the impact shock experiments. This indicates that this important prebiotic molecule was also synthesized by impacts of iron-bearing meteorites/asteroids on the Hadean oceans. The impact events might have generated spatially and temporally FA-enriched localized environments. Moreover, the impact-induced synthesis of FA may have also occurred on Noachian Mars given the presence of liquid water and a CO2-N-2-rich atmosphere on the planet.

  28. Decompression experiments for sulfur-bearing hydrous rhyolite magma: Redox evolution during magma decompression

    Satoshi Okumura, Hidemi Ishibashi, Shoichi Itoh, Akimasa Suzumura, Yoshihiro Furukawa, Takahiro Miwa, Hiroyuki Kagi

    American Mineralogist 106 (2) 216-225 2021年

    出版者・発行元:None

    DOI: 10.2138/am-2020-7535  

    ISSN:0003-004X

    eISSN:1945-3027

  29. Aqueous alteration without initial water: possibility of organic-induced hydration of anhydrous silicates in meteorite parent bodies

    Naoki Hirakawa, Yoko Kebukawa, Yoshihiro Furukawa, Masashi Kondo, Hideyuki Nakano, Kensei Kobayashi

    Earth, Planets and Space 73 (1) 16 2021年

    出版者・発行元:None

    DOI: 10.1186/s40623-020-01352-6  

    eISSN:1880-5981

  30. Airfall on Comet 67P/Churyumov–Gerasimenko 査読有り

    Björn J.R. Davidsson, Samuel Birch, Geoffrey A. Blake, Dennis Bodewits, Jason P. Dworkin, Daniel P. Glavin, Yoshihiro Furukawa, Jonathan I. Lunine, Julie L. Mitchell, Ann N. Nguyen, Steve Squyres, Aki Takigawa, Jean-Baptiste Vincent, Kris Zacny

    Icarus 354 114004-114004 2021年1月

    出版者・発行元:Elsevier {BV}

    DOI: 10.1016/j.icarus.2020.114004  

    ISSN:0019-1035

    eISSN:1090-2643

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    We here study the transfer process of material from one hemisphere to the other (deposition of airfall material) on an active comet nucleus, specifically 67P/Churyumov-Gerasimenko. Our goals are to: 1) quantify the thickness of the airfall debris layers and how it depends on the location of the target area, 2) determine the amount of H2O and CO2 ice that are lost from icy dust assemblages of different sizes during transfer through the coma, and 3) estimate the relative amount of vapor loss in airfall material after deposition in order to understand what locations are expected to be more active than others on the following perihelion approach.We use various numerical simulations, that include orbit dynamics, thermophysics of the nucleus and of individual coma aggregates, coma gas kinetics and hydrodynamics, as well as dust dynamics due to gas drag, to address these questions. We find that the thickness of accumulated airfall material varies substantially with location, and typically is of the order 0.1-1 m. The airfall material preserves substantial amounts of water ice even in relatively small (cm-sized) coma aggregates after a rather long (12h) residence in the coma. However, CO2 is lost within a couple of hours even in relatively large (dm-sized) aggregates, and is not expected to be an important component in airfall deposits. We introduce reachability and survivability indices to measure the relative capacity of different regions to simultaneously collect airfall and to preserve its water ice until the next perihelion passage, thereby grading their potential of contributing to comet activity during the next perihelion passage.

  31. Extraterrestrial hexamethylenetetramine in meteorites—a precursor of prebiotic chemistry in the inner solar system 査読有り

    Yasuhiro Oba, Yoshinori Takano, Hiroshi Naraoka, Yoshihiro Furukawa, Daniel P. Glavin, Jason P. Dworkin, Shogo Tachibana

    Nature Communications 11 (1) 2020年12月

    出版者・発行元:Springer Science and Business Media {LLC}

    DOI: 10.1038/s41467-020-20038-x  

    eISSN:2041-1723

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    <title>Abstract</title>Despite extensive studies on the formation of organic molecules in various extraterrestrial environments, it still remains under debate when, where, and how such molecules were abiotically formed. A key molecule to solve the problem, hexamethylenetetramine (HMT) has not been confirmed in extraterrestrial materials despite extensive laboratory experimental evidence that it can be produced in interstellar or cometary environments. Here we report the first detection of HMT and functionalized HMT species in the carbonaceous chondrites Murchison, Murray, and Tagish Lake. While the part-per-billion level concentration of HMT in Murchison and Tagish Lake is comparable to other related soluble organic molecules like amino acids, these compounds may have eluded detection in previous studies due to the loss of HMT during the extraction processes. HMT, which can yield important molecules for prebiotic chemistry such as formaldehyde and ammonia upon degradation, is a likely precursor of meteoritic organic compounds of astrochemical and astrophysical interest.

  32. Impact-induced amino acid formation on Hadean Earth and Noachian Mars 査読有り

    Yuto Takeuchi, Yoshihiro Furukawa, Takamichi Kobayashi, Toshimori Sekine, Naoki Terada, Takeshi Kakegawa

    Scientific Reports 10 (1) 2020年12月

    出版者・発行元:Springer Science and Business Media {LLC}

    DOI: 10.1038/s41598-020-66112-8  

    ISSN:2045-2322

    eISSN:2045-2322

  33. The Importance of Phobos Sample Return for Understanding the Mars-Moon System 査読有り

    Tomohiro Usui, Ken-ichi Bajo, Wataru Fujiya, Yoshihiro Furukawa, Mizuho Koike, Yayoi N. Miura, Haruna Sugahara, Shogo Tachibana, Yoshinori Takano, Kiyoshi Kuramoto

    Space Science Reviews 216 (4) 2020年4月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s11214-020-00668-9  

    ISSN:0038-6308

    eISSN:1572-9672

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    Phobos and Deimos occupy unique positions both scientifically and programmatically on the road to the exploration of the solar system. Japan Aerospace Exploration Agency (JAXA) plans a Phobos sample return mission (MMX: Martian Moons eXploration). The MMX spacecraft is scheduled to be launched in 2024, orbit both Phobos and Deimos (multiple flybys), and retrieve and return >10 g of Phobos regolith back to Earth in 2029. The Phobos regolith represents a mixture of endogenous Phobos building blocks and exogenous materials that contain solar system projectiles (e.g., interplanetary dust particles and coarser materials) and ejecta from Mars and Deimos. Under the condition that the representativeness of the sampling site(s) is guaranteed by remote sensing observations in the geologic context of Phobos, laboratory analysis (e.g., mineralogy, bulk composition, O-Cr-Ti isotopic systematics, and radiometric dating) of the returned sample will provide crucial information about the moon's origin: capture of an asteroid or in-situ formation by a giant impact. If Phobos proves to be a captured object, isotopic compositions of volatile elements (e.g., D/H, C-13/C-12, N-15/N-14) in inorganic and organic materials will shed light on both organic-mineral-water/ice interactions in a primitive rocky body originally formed in the outer solar system and the delivery process of water and organics into the inner rocky planets.

  34. Exposure Experiments of Amorphous Silicates and Organics to Cometary Ice and Vapor Analogs 査読有り

    Aki Takigawa, Yoshihiro Furukawa, Yuki Kimura, Bjorn Davidsson, Tomoki Nakamura

    The Astrophysical Journal 881 (1) 2019年8月

    出版者・発行元:IOP PUBLISHING LTD

    DOI: 10.3847/1538-4357/ab27c6  

    ISSN:0004-637X

    eISSN:1538-4357

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    Hydration is a major mineral alteration process in primitive asteroids and it might occur in comet nuclei; however, it is poorly understood at low temperatures, especially below the freezing point of water. Long-duration experiments were performed with exposures of amorphous silicate nanoparticles and organic compounds (glycine and ribose) to D2O and D2O + NH3 ices and vapors at temperatures of -17 degrees C and -27 degrees C for 10-120 days; and with exposure of amorphous silicates to H2O vapor/liquid at >25 degrees C for 10 days. The amorphous silicates were analyzed by X-ray diffraction and Fourier-transform infrared spectroscopy, and recovery of organic molecules was determined by liquid chromatography-mass spectrometry. No hydration of amorphous silicates or organic compounds was observed after exposure at temperatures below -17 degrees C for 120 days to ices with or without NH3, whereas hydration of the amorphous silicates was observed in experiments above room temperature. The estimated thermal history of the nucleus of the short-period comet 67P/Churyumov-Gerasimenko indicates that the surface temperature does not exceed -45 degrees C, even in a region exposed to strong solar illumination during the perihelion passage. Assuming hydration is controlled by the collision frequency between H2O molecules and dust particles, the present results indicate that cometary dust does not hydrate for more than 25-510 periods of comet 67P. This is consistent with the absence of phyllosilicates on 67P and suggests that amino acids and sugars have not been altered.

  35. STXM-XANES analyses of Murchison meteorite samples captured by aerogel after hypervelocity impacts: A potential implication of organic matter degradation for micrometeoroid collection experiments 査読有り

    Yoko Kebukawa, Kyoko Okudaira, Hikaru Yabuta, Sunao Hasegawa, Makoto Tabata, Yoshihiro Furukawa, Motoo Ito, Aiko Nakato, A. L. David Kilcoyne, Kensei Kobayashi, Shin-ichi Yokobori, Eiichi Imai, Yuko Kawaguchi, Hajime Yano, Akihiko Yamagishi

    Geochemical Journal 53 (1) 53-67 2019年

    出版者・発行元:GEOCHEMICAL SOC JAPAN

    DOI: 10.2343/geochemj.2.0549  

    ISSN:0016-7002

    eISSN:1880-5973

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    The Tanpopo mission is an astrobiology space experiment at the Japanese Experiment Module (JEM) 'Kibo' on the International Space Station (ISS). One of the sub-divided themes of the Tanpopo mission is for the intact capture of organic bearing micrometeoroids in low Earth orbit using ultralow density silica aerogel (0.01 g/cm(3)). In order to evaluate damage to organic matter in micrometeoroids during hyper velocity impacts into the aerogel, Murchison meteorite powdered samples, analogs of organic bearing micrometeoroids, were fired into flight-grade silica aerogel (0.01 g/cm(3)) using a two-stage light-gas gun with velocities of 4.4 and 5.9 km/s. The recovered Murchison grains were analyzed using scanning transmission X-ray microscopy/X-ray absorption near edge structure (STXM/XANES), transmission electron microscopy (TEM) and nanoscale secondary ion mass spectrometry (NanoSIMS). TEM observation did not show significant modifications of the recovered Murchison grains. Carbon-XANES spectra, however, showed a large depletion of the organic matter after the 5.9 km/s impact, but no such effects nor any significant hydrogen isotopic fractionation were observed after the 4.4 km/s impact.

  36. SPECTRAL AND WATER ANALYSIS OF EXPERIMENTALLY HEATED TAGISH LAKE AND CR CARBONACEOUS CHONDRITES WITH NO EFFECTS OF ADSORBED AND REHYDRATED WATER. 査読有り

    Kana Amano, Kaoru Mogi, Tomoki Nakamura, Moe Matsuoka, Yoshihiro Furukawa, Satoshi Okumura

    METEORITICS & PLANETARY SCIENCE 53 6309-6309 2018年8月

    出版者・発行元:WILEY

    ISSN:1086-9379

    eISSN:1945-5100

  37. Racemization of Valine by Impact-Induced Heating 査読有り

    Yoshihiro Furukawa, Atsushi Takase, Toshimori Sekine, Takeshi Kakegawa, Takamichi Kobayashi

    ORIGINS OF LIFE AND EVOLUTION OF BIOSPHERES 48 (1) 131-139 2018年3月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s11084-017-9539-0  

    ISSN:0169-6149

    eISSN:1573-0875

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    Homochirality plays an important role in all living organisms but its origin remains unclear. It also remains unclear whether such chiral molecules survived terrestrial heavy impact events. Impacts of extraterrestrial objects on early oceans were frequent and could have affected the chirality of oceanic amino acids when such amino acids accumulated during impacts. This study investigated the effects of shock-induced heating on enantiomeric change of valine with minerals such as olivine ([Mg-0.9, Fe-0.1](2)SiO4), hematite (Fe2O3), and calcite (CaCO3). With a shock wave generated by an impact at similar to 0.8 km/s, both d- and l-enriched valine were significantly decomposed and partially racemized under all experimental conditions. Different minerals had different shock impedances; therefore, they provided different P-T conditions for identical impacts. Furthermore, the high pH of calcite promoted the racemization of valine. The results indicate that in natural hypervelocity impacts, amino acids in shocked oceanic water would have decomposed completely, since impact velocity and the duration of shock compression and heating are typically greater in hypervelocity impact events than those in experiments. Even with the shock wave by the impact of small and decelerated projectiles in which amino acids survive, the shock heating may generate sufficient heat for significant racemization in shocked oceanic water. However, the duration of shock induced heating by small projectiles is limited and the population of such decelerated projectiles would be limited. Therefore, even though impacts of asteroids and meteorites were frequent on the prebiotic Earth, impact events would not have significantly changed the ee of proteinogenic amino acids accumulated in the entire ocean.

  38. DEHYDRATION PROCESS OF EXPERIMENTALLY HEATED MURCHISON WITHOUT ANY EFFECTS OF ADSORBED AND REHYDRATED WATER 査読有り

    Kaoru Mogi, Sayuri Yamashita, Tomoki Nakamura, Moe Matsuoka, Satoshi Okumura, Yoshihiro Furukawa

    METEORITICS & PLANETARY SCIENCE 52 A240-A240 2017年8月

    出版者・発行元:WILEY

    ISSN:1086-9379

    eISSN:1945-5100

  39. Temperature-induced oligomerization of polycyclic aromatic hydrocarbons at ambient and high pressures 査読有り

    Artem D. Chanyshev, Konstantin D. Litasov, Yoshihiro Furukawa, Konstantin A. Kokh, Anton F. Shatskiy

    Scientific Reports 7 7889 2017年8月

    出版者・発行元:NATURE PUBLISHING GROUP

    DOI: 10.1038/s41598-017-08529-2  

    ISSN:2045-2322

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    Temperature-induced oligomerization of polycyclic aromatic hydrocarbons (PAHs) was found at 500-773 K and ambient and high (3.5 GPa) pressures. The most intensive oligomerization at 1 bar and 3.5 GPa occurs at 740-823 K. PAH carbonization at high pressure is the final stage of oligomerization and occurs as a result of sequential oligomerization and polymerization of the starting material, caused by overlapping of pi-orbitals, a decrease of intermolecular distances, and finally the dehydrogenation and polycondensation of benzene rings. Being important for building blocks of life, PAHs and their oligomers can be formed in the interior of the terrestrial planets with radii less than 2270 km.

  40. Effects of Glycine, Water, Ammonia, and Ammonium Bicarbonate on the Oligomerization of Methionine 査読有り

    Rui Huang, Yoshihiro Furukawa, Tsubasa Otake, Takeshi Kakegawa

    ORIGINS OF LIFE AND EVOLUTION OF BIOSPHERES 47 (2) 145-160 2017年6月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s11084-016-9518-x  

    ISSN:0169-6149

    eISSN:1573-0875

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    The abiotic oligomerization of amino acids may have created primordial, protein-like biological catalysts on the early Earth. Previous studies have proposed and evaluated the potential of diagenesis for the amino acid oligomerization, simulating the formation of peptides that include glycine, alanine, and valine, separately. However, whether such conditions can promote the formation of peptides composed of multiple amino acids remains unclear. Furthermore, the chemistry of pore water in sediments should affect the oligomerization and degradation of amino acids and oligomers, but these effects have not been studied extensively. In this study, we investigated the effects of water, ammonia, ammonium bicarbonate, pH, and glycine on the oligomerization and degradation of methionine under high pressure (150 MPa) and high temperature conditions (175 A degrees C) for 96 h. Methionine is more difficult to oligomerize than glycine and methionine dimer was formed in the incubation of dry powder of methionine. Methionine oligomers as long as trimers, as well as methionylglycine and glycylmethionine, were formed under every condition with these additional compounds. Among the compounds tested, the oligomerization reaction rate was accelerated by the presence of water and by an increase in pH. Ammonia also increased the oligomerization rate but consumed methionine by side reactions and resulted in the rapid degradation of methionine and its peptides. Similarly, glycine accelerated the oligomerization rate of methionine and the degradation of methionine, producing water, ammonia, and bicarbonate through its decomposition. With Gly, heterogeneous dimers (methionylglycine and glycylmethionine) were formed in greater amounts than with other additional compounds although smaller amount of these heterogeneous dimers were formed with other additional compounds. These results suggest that accelerated reaction rates induced by water and co-existing reactive compounds promote the oligomerization of less reactive amino acids during diagenesis and enhance the formation of peptides composed of multiple amino acids.

  41. Morphological changes of olivine grains reacted with amino acid solutions by impact process 査読有り

    Yuhei Umeda, Atsushi Takase, Nao Fukunaga, Toshimori Sekine, Takamichi Kobayashi, Yoshihiro Furukawa, Takeshi Kakegawa

    PHYSICS AND CHEMISTRY OF MINERALS 44 (3) 203-212 2017年3月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s00269-016-0849-y  

    ISSN:0342-1791

    eISSN:1432-2021

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    Early oceans on Earth might have contained certain amounts of biomolecules such as amino acids, and they were subjected to meteorite impacts, especially during the late heavy bombardment. We performed shock recovery experiments by using a propellant gun in order to simulate shock reactions among olivine as a representative meteorite component, water and biomolecules in oceans in the process of marine meteorite impacts. In the present study, recovered solid samples were analyzed by using X-ray powder diffraction method, scanning electron microscopy, electron probe microanalysis, and transmission electron microscopy with energy-dispersive X-ray spectrometry. The analytical results on shocked products in the recovered sample showed (1) morphological changes of olivine to fiber- and bamboo shoot-like crystals, and to pulverized grains; and features of lumpy surfaces affected by hot water, (2) the formation of carbon-rich substances derived from amino acids, and (3) the incorporation of metals from container into samples. According to the present results, fine-grained olivine in meteorites might have morphologically changed and shock-induced chemical reactions might have been enhanced so that amino acids related to the origin of life may have transformed to carbon-rich substances by impacts.

  42. Adsorption of RNA on mineral surfaces and mineral precipitates 査読有り

    Elisa Biondi, Yoshihiro Furukawa, Jun Kawai, Steven A. Benner

    BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY 13 393-404 2017年3月

    出版者・発行元:BEILSTEIN-INSTITUT

    DOI: 10.3762/bjoc.13.42  

    ISSN:1860-5397

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    The prebiotic significance of laboratory experiments that study the interactions between oligomeric RNA and mineral species is difficult to know. Natural exemplars of specific minerals can differ widely depending on their provenance. While laboratory-generated samples of synthetic minerals can have controlled compositions, they are often viewed as "unnatural". Here, we show how trends in the interaction of RNA with natural mineral specimens, synthetic mineral specimens, and co-precipitated pairs of synthetic minerals, can make a persuasive case that the observed interactions reflect the composition of the minerals themselves, rather than their being simply examples of large molecules associating nonspecifically with large surfaces. Using this approach, we have discovered Periodic Table trends in the binding of oligomeric RNA to alkaline earth carbonate minerals and alkaline earth sulfate minerals, where those trends are the same when measured in natural and synthetic minerals. They are also validated by comparison of co-precipitated synthetic minerals. We also show differential binding of RNA to polymorphic forms of calcium carbonate, and the stabilization of bound RNA on aragonite. These have relevance to the prebiotic stabilization of RNA, where such carbonate minerals are expected to have been abundant, as they appear to be today on Mars.

  43. Evaporite Borate-Containing Mineral Ensembles Make Phosphate Available and Regiospecifically Phosphorylate Ribonucleosides: Borate as a Multifaceted Problem Solver in Prebiotic Chemistry 査読有り

    Hyo-Joong Kim, Yoshihiro Furukawa, Takeshi Kakegawa, Andrei Bita, Romulus Scorei, Steven A. Benner

    Angewandte Chemie International Edition 55 (51) 15816-15820 2016年12月

    出版者・発行元:WILEY-V C H VERLAG GMBH

    DOI: 10.1002/anie.201608001  

    ISSN:1433-7851

    eISSN:1521-3773

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    RNA is currently thought to have been the first biopolymer to support Darwinian natural selection on Earth. However, the phosphate esters in RNA and its precursors, and the many sites at which phosphorylation might occur in ribonucleosides under conditions that make it possible, challenge prebiotic chemists. Moreover, free inorganic phosphate may have been scarce on early Earth owing to its sequestration by calcium in the unreactive mineral hydroxyapatite. Herein, it is shown that these problems can be mitigated by a particular geological environment that contains borate, magnesium, sulfate, calcium, and phosphate in evaporite deposits. Actual geological environments, reproduced here, show that Mg2+ and borate sequester phosphate from calcium to form the mineral luneburgite. Ribonucleosides stabilized by borate mobilize borate and phosphate from luneburgite, and are then regiospecifically phosphorylated by the mineral. Thus, in addition to guiding carbohydrate pre-metabolism, borate minerals in evaporite geoorganic contexts offer a solution to the phosphate problem in the RNA first model for the origins of life.

  44. Effects of Silicate, Phosphate, and Calcium on the Stability of Aldopentoses 査読有り

    Sakiko Nitta, Yoshihiro Furukawa, Takeshi Kakegawa

    ORIGINS OF LIFE AND EVOLUTION OF BIOSPHERES 46 (2-3) 189-202 2016年6月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s11084-015-9472-z  

    ISSN:0169-6149

    eISSN:1573-0875

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    Ribose is an important constituent of RNA: ribose connects RNA bases and forms a strand of sugar phosphates. Accumulation of ribose on prebiotic Earth was difficult because of its low stability. Improvement in the yield of ribose by the introduction of borate or silicate in a formose-like reaction has been proposed. The effects of borates have been further analyzed and confirmed in subsequent studies. Nonetheless, the effects of silicates and phosphates remain unclear. In the present study, we incubated aldopentoses in a highly alkaline aqueous solution at a moderate temperature to determine the effects of silicate or phosphate on the degradation rates of ribose and its isomeric aldopentoses. The formation of a complex of silicate (or phosphate) with ribose was also analyzed in experiments with Si-29 and P-31 nuclear magnetic resonance (NMR). We found that silicate or phosphate complexes of ribose were not detectable under our experimental conditions. The stability of ribose and lyxose improved after addition of 40-fold molar excess (relative to a pentose) of sodium silicate or sodium phosphate to the alkaline solution. The stability was not improved further when an 80-fold molar excess of sodium silicate or sodium phosphate was added. Calcium was removed from these solutions by precipitation of calcium salts. The drop in Ca2+ concentration might have improved the stability of ribose and lyxose, which are susceptible to aldol addition. The improvement of ribose stability by the removal of Ca2+ and by addition of silicate or phosphate was far smaller than the improvement by borate. Furthermore, all aldopentoses showed similar stability in silicate-and phosphate-containing solutions. These results clearly show that selective stabilization of ribose by borate cannot be replaced by the effects of silicate or phosphate; this finding points to the importance of borate in prebiotic RNA formation.

  45. 初期地球における隕石衝突によるアミノ酸および核酸塩基の生成に関する研究

    古川 善博

    地球化学 50 (1) 1-9 2016年

    出版者・発行元:日本地球化学会

    DOI: 10.14934/chikyukagaku.50.1  

    ISSN:0386-4073

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    Emergence of lifes building blocks on the prebiotic Earth should be the fundamental step to the origins of life. Geological evidences suggest that such organic compounds accumulated at some point in the time between 4.4 to 3.8 billion years ago. During this period, the flux of extraterrestrial objects was significantly higher than the subsequent periods. Such extraterrestrial objects might have provided substantial amounts of metallic iron to the surface of the Earth. Shock-recovery experiments simulating the impact-induced reactions of such iron-bearing objects suggest that hypervelocity oceanic impacts of meteorites form nucleobases and various amino acids as well as amines and carboxylic acids. High annual mass flux of such large objects suggests that the impact-induced formation was not negligible as a source of organic compounds on the early Earth. Further investigations on the impact-induced reactions and the nature of extraterrestrial objects would elucidate the fundamental step to the origin of life.

  46. 「アーリーアース・ケミストリー(Early Earth Chemistry)」のプロローグ

    古川 善博, 高野 淑識

    地球化学 50 (3) 117-119 2016年

    出版者・発行元:日本地球化学会

    DOI: 10.14934/chikyukagaku.50.117  

    ISSN:0386-4073

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    <p>Through the history of the Earth, surface environments had changed most dramatically on the early Earth, characterized by the formation of ocean, continents, and life. Large amounts of unclear points remained on the origin of life. Thus, this research area has large amounts of open questions to be achieved in the future. Geochemistry is one of the most powerful tool to answer the questions related to the origins of life. This special issue "Early Earth Chemistry" brings six review articles, in which the authors introduced unique aspects and recent progresses from the view of individual expertise. The contents cover the formation of oceans, formation of continents, impact events, prebiotic chemistry, and potential geological records of early life. We hope that you'll make the best from those overview contents and that this issue works to spread further novel research frameworks.</p>

  47. Survivability and reactivity of glycine and alanine in early oceans: effects of meteorite impacts 査読有り

    Yuhei Umeda, Nao Fukunaga, Toshimori Sekine, Yoshihiro Furukawa, Takeshi Kakegawa, Takamichi Kobayashi, Hiromoto Nakazawa

    JOURNAL OF BIOLOGICAL PHYSICS 42 (1) 177-198 2016年1月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s10867-015-9400-5  

    ISSN:0092-0606

    eISSN:1573-0689

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    Prebiotic oceans might have contained abundant amino acids, and were subjected to meteorite impacts, especially during the late heavy bombardment. It is so far unknown how meteorite impacts affected amino acids in the early oceans. Impact experiments were performed under the conditions where glycine was synthesized from carbon, ammonia, and water, using aqueous solutions containing C-13-labeled glycine and alanine. Selected amino acids and amines in samples were analyzed with liquid chromatography-mass spectrometry (LC/MS). In particular, the C-13-labeled reaction products were analyzed to distinguish between run products and contaminants. The results revealed that both amino acids survived partially in the early ocean through meteorite impacts, that part of glycine changed into alanine, and that large amounts of methylamine and ethylamine were formed. Fast decarboxylation was confirmed to occur during such impact processes. Furthermore, the formation of n-butylamine, detected only in the samples recovered from the solutions with additional nitrogen and carbon sources of ammonia and benzene, suggests that chemical reactions to form new biomolecules can proceed through marine impacts. Methylamine and ethylamine from glycine and alanine increased considerably in the presence of hematite rather than olivine under similar impact conditions. These results also suggest that amino acids present in early oceans can contribute further to impact-induced reactions, implying that impact energy plays a potential role in the prebiotic formation of various biomolecules, although the reactions are complicated and depend upon the chemical environments as well.

  48. Shock wave synthesis of amino acids from solutions of ammonium formate and ammonium bicarbonate 査読有り

    Chizuka Suzuki, Yoshihiro Furukawa, Takamichi Kobayashi, Toshimori Sekine, Hiromoto Nakazawa, Takeshi Kakegawa

    GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS 16 (7) 2382-2394 2015年7月

    出版者・発行元:AMER GEOPHYSICAL UNION

    DOI: 10.1002/2015GC005783  

    ISSN:1525-2027

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    The emergence of life's building blocks, such as amino acids and nucleobases, on the prebiotic Earth was a critical step for the beginning of life. Reduced species with low mass, such as ammonia, amines, or carboxylic acids, are potential precursors for these building blocks of life. These precursors may have been provided to the prebiotic ocean by carbonaceous chondrites and chemical reactions related to meteorite impacts on the early Earth. The impact of extraterrestrial objects on Earth occurred more frequently during this period than at present. Such impacts generated shock waves in the ocean, which have the potential to progress chemical reactions to form the building blocks of life from reduced species. To simulate shock-induced reactions in the prebiotic ocean, we conducted shock-recovery experiments on ammonium bicarbonate solution and ammonium formate solution at impact velocities ranging from 0.51 to 0.92 km/s. In the products from the ammonium formate solution, several amino acids (glycine, alanine, ss-alanine, and sarcosine) and aliphatic amines (methylamine, ethylamine, propylamine, and butylamine) were detected, although yields were less than 0.1 mol % of the formic acid reactant. From the ammonium bicarbonate solution, smaller amounts of glycine, methylamine, ethylamine, and propylamine were formed. The impact velocities used in this study represent minimum cases because natural meteorite impacts typically have higher velocities and longer durations. Our results therefore suggest that shock waves could have been involved in forming life's building blocks in the ocean of prebiotic Earth, and potentially in aquifers of other planets, satellites, and asteroids.

  49. Oligomerization and carbonization of polycyclic aromatic hydrocarbons at high pressure and temperature 査読有り

    Artem D. Chanyshev, Konstantin D. Litasov, Anton F. Shatskiy, Yoshihiro Furukawa, Takashi Yoshino, Eiji Ohtani

    CARBON 84 225-235 2015年4月

    出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD

    DOI: 10.1016/j.carbon.2014.12.011  

    ISSN:0008-6223

    eISSN:1873-3891

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    We have examined the stabilities of different polycyclic aromatic hydrocarbons (PAHs) at 7 GPa and 773-973 K and at 16 GPa and 300 K. Experiments were performed using a large-volume multi-anvil apparatus. Quenched products were analyzed by matrix-assisted laser desorption/ionization (MALDI) and Raman spectroscopy. The MALDI measurements revealed the considerable oligomerization of PAHs at 7 GPa and 773-873 K and insignificant PAH oligomerization at 16 GPa and 300K. At 7 GPa and 773 K, oligomers with molecular weight up to 3400 Da were found, while only a small number of dimers of the starting PAHs were detected at 16 GPa and 300K. PAH decomposition at 7 GPa occurred from 873 to 973 K, and the decomposition products consisted of nanocrystalline graphite. The determined decomposition temperatures of the PAHs (873-973 K) are much lower than Earth's geotherms and the subduction slab P-T profiles at 7 GPa; therefore, PAH inclusions in mantle-derived minerals, which can be crystallized at 6-7 GPa and 1600-1700 K, should be secondary phases and could be formed by the successive polycondensation of simple hydrocarbon molecules under natural catalysts during eruption processes at sub-ambient pressures and temperatures. (C) 2014 Elsevier Ltd. All rights reserved.

  50. Erratum: “Stability conditions of polycyclic aromatic hydrocarbons at high pressures and temperatures” [Geochemistry International 52, (2014), 767, DOI 10.1134/S001670291424001X] 査読有り

    A. D. Chanyshev, K. D. Litasov, A. F. Shatskiy, Y. Furukawa, E. Ohtani

    Geochemistry International 52 (11) 1011 2014年10月21日

    出版者・発行元:Maik Nauka-Interperiodica Publishing

    DOI: 10.1134/S001670291424001X  

    ISSN:1556-1968 0016-7029

  51. Stability Conditions of Polycyclic Aromatic Hydrocarbons at High Pressures and Temperatures 査読有り

    A. D. Chanyshev, K. D. Litasov, A. F. Shatskiy, J. Furukawa, E. Ohtani

    GEOCHEMISTRY INTERNATIONAL 52 (9) 767-772 2014年9月

    出版者・発行元:MAIK NAUKA/INTERPERIODICA/SPRINGER

    DOI: 10.1134/S001670291409002X  

    ISSN:0016-7029

    eISSN:1556-1968

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    The first results of study of stability of diverse polycyclic aromatic hydrocarbons at around 7 GPa and 773-1073 K are reported. Experiments were carried out in hydraulic multi-anvil presses. The run products after quenching were analyzed using a method of matrix-assisted laser desorption-ionization (MALDI). The formation of polymers of starting matters was determined at 7 GPa and 773-883 K. The polymers are characterized by atomic masses up to 5000 Da, that are multiple by masses of starting matters. At higher temperatures (873-1073 K), the selected PAHs and their polymers become unstable. The decomposition temperature of PAHs and their polymers exclude their stability under Earth's mantle conditions. The studies could be of great significance for the low-temperature near-surface geodynamics of small and large planetary bodies, which supposedly contain hydrocarbon compounds.

  52. Experimental investigation of reduced volatile formation by high-temperature interactions among meteorite constituent materials, water, and nitrogen 査読有り

    Yoshihiro Furukawa, Taro Samejima, Hiromoto Nakazawa, Takeshi Kakegawa

    ICARUS 231 77-82 2014年3月

    出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE

    DOI: 10.1016/j.icarus.2013.11.033  

    ISSN:0019-1035

    eISSN:1090-2643

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    Late heavy bombardment (LHB) of extraterrestrial objects supplied carbon with metals to the prebiotic Earth. The early oceans were the major target of these impacts, followed by interactions among the atmosphere, oceanic water, and meteorite constituent materials under high-temperature and high-pressure conditions. Post-impact reactions of these hypervelocity impacts have the potential to produce reduced volatiles and organic compounds, including amino acids. Therefore, understanding the reactions in post-impact plumes is of great importance for the investigation of prebiotic organic compounds. The composition of post-impact plumes has been investigated with thermochemical calculations. However, experimental evidence is still needed to understand the reactions in dynamic systems of post-impact plumes. The present study investigates the effects of reaction temperature and availability of water on products from iron, nickel, graphite, nitrogen, and water in a dynamic gas flow system to investigate reactions in post-impact plumes. Results of this study indicate the formation of CO, H-2, NH3, and HCN by hypervelocity oceanic impacts of iron-rich extraterrestrial objects. The formation of methane was limited in the present experiments, suggesting that the quenching rate is an influential factor for methane formation in post-impact plumes. Availability of water vapor in the plume was also an influential factor for the formation of reduced volatiles that controlled the CO formation rate from graphite. These results provide experimental evidence for the formation of reduced volatiles in post-impact plumes, which influenced the formation of prebiotic organic compounds. (c) 2013 Elsevier Inc. All rights reserved.

  53. Experimental investigation of reduced volatile formation by high-temperature interactions among meteorite constituent materials, water, and nitrogen 査読有り

    Furukawa Y, Samejima T, Nakazawa H, Kakegawa T

    ICARUS 2014年1月

    DOI: 10.1016/j.icarus.2013.11.033  

  54. Exploration of Enceladus’ water-rich plumes toward understanding of chemistry and biology of the interior ocean 招待有り 査読有り

    Sekine Y, Takano Y, Yano H, Funase R, Takai K, Ishihara M, Shibuya T, Tachibana S, Kuramoto K, Yabuta H, Kimura J, Furukawa Y

    Aerospace Technology Japan, The ISTS Special Issue of Transactions of JSASS 12 (ists29) Tk7-Tk11 2014年

    DOI: 10.2322/tastj.12.Tk_7  

  55. Selective Stabilization of Ribose by Borate 査読有り

    Yoshihiro Furukawa, Mana Horiuchi, Takeshi Kakegawa

    ORIGINS OF LIFE AND EVOLUTION OF BIOSPHERES 43 (4-5) 353-361 2013年10月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s11084-013-9350-5  

    ISSN:0169-6149

    eISSN:1573-0875

    詳細を見る 詳細を閉じる

    In this study, borate was found to selectively increase the stability of ribose over other aldopentoses. Ribose is the only sugar present in both early RNA-based biochemistry and contemporary DNA-based life, and the stability of ribose is of fundamental concern for determining the origin of early RNA-based biochemistry. The formose reaction is a potential process in the prebiotic synthesis of ribose and its stereoisomers arabinose, xylose, and lyxose. Ribose is the least stable of these aldopentoses, raising the fundamental question of whether it was originally a component of primitive RNA or was selected through biotic processes. Borate is known to increase the stability of aldopentoses, but the specific differences in the stabilization achieved among different stereoisomers remain unclear. In this study, it was found that the stabilities of all of the tested pentoses increased with the concentration of added borate, but notably, the stability of ribose increased the most. The predominant formation of complexes between borate and ribose was verified, in agreement with previous studies. This borate complex formation might have sequestered ribose from the isomerization and decomposition reactions, resulting in its selective stabilization. These findings indicate that ribose could have accumulated in borate-rich environments on the early Earth and suggest that ribose-based nucleotides combined with phosphate and nucleobases formed abiotically.

  56. Abiotic Formation of Valine Peptides Under Conditions of High Temperature and High Pressure 査読有り

    Yoshihiro Furukawa, Tsubasa Otake, Takato Ishiguro, Hiromoto Nakazawa, Takeshi Kakegawa

    ORIGINS OF LIFE AND EVOLUTION OF BIOSPHERES 42 (6) 519-531 2012年12月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s11084-012-9295-0  

    ISSN:0169-6149

    eISSN:1573-0875

    詳細を見る 詳細を閉じる

    We investigated the oligomerization of solid valine and the stabilities of valine and valine peptides under conditions of high temperature (150-200 A degrees C) and high pressure (50-150 MPa). Experiments were performed under non-aqueous condition in order to promote dehydration reaction. After prolonged exposure of monomeric valine to elevated temperatures and pressures, the products were analyzed by liquid chromatography mass spectrometry comparing their retention times and masses. We identified linear peptides that ranged in size from dimer to hexamer, as well as a cyclic dimer. Previous studies that attempted abiotic oligomerization of valine in the absence of a catalyst have never reported valine peptides larger than a dimer. Increased reaction temperature increased the dissociative decomposition of valine and valine peptides to products such as glycine, beta-alanine, ammonia, and amines by processes such as deamination, decarboxylation, and cracking. The amount of residual valine and peptide yields was greater at higher pressures at a given temperature, pressure, and reaction time. This suggests that dissociative decomposition of valine and valine peptides is reduced by pressure. Our findings are relevant to the investigation of diagenetic processes in prebiotic marine sediments where similar pressures occur under water-poor conditions. These findings also suggest that amino acids, such as valine, could have been polymerized to peptides in deep prebiotic marine sediments within a few hundred million years.

  57. Impact-induced phyllosilicate formation from olivine and water 査読有り

    Yoshihiro Furukawa, Toshimori Sekine, Takeshi Kakegawa, Hiromoto Nakazawa

    GEOCHIMICA ET COSMOCHIMICA ACTA 75 (21) 6461-6472 2011年11月

    出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD

    DOI: 10.1016/j.gca.2011.08.029  

    ISSN:0016-7037

    eISSN:1872-9533

    詳細を見る 詳細を閉じる

    Shock-recovery experiments on mixtures of olivine and water with gas (air) were performed in a previous study to demonstrate water-mineral interactions during impact events (Furukawa et al., 2007). The products of these former experiments were investigated in the present study using transmission electron microscopy, scanning electron microscopy, and X-ray powder diffraction with the aim of finding evidence of aqueous alteration. Serpentine formed on the surface of shocked olivine with well-developed mosaicism. The yield of serpentine depended on the water/olivine ratio in the starting material, indicating progressive serpentinization under water-rich conditions. Comminution and mosaicism were developed in shocked olivine grains. The temperature and pressure changes of the samples during the experiments were estimated by constructing Hugoniots for mixtures of olivine and water, combined with the results of an additional fracturing experiment on a shocked container. Pressures and temperatures reached 4.6-7.2 GPa and at least 230-390 degrees C, respectively, for 0.7 mu s during in-shock compression. Post-shock temperatures reached a maximum of similar to 1300 degrees C, when the shock wave reached the gas in the sample cavity. The serpentine formed after the post-shock temperature maximum, most likely when temperatures dropped to between 200 and 400 degrees C. This is the first experiment to demonstrate the formation of phyllosilicates using heat supplied by an impact. The present results and estimations suggest that phyllosilicates could form as a result of impacts into oceans as well as by impacts on terrestrial and Martian crustal rocks, and on some asteroidal surfaces, where liquid or solid H2O is available. A significant amount of phyllosilicates would have formed during the late heavy bombardment of meteorites on the Hadean Earth, and such phyllosilicates might have affected the prebiotic carbon cycle. (C) 2011 Elsevier Ltd. All rights reserved.

  58. Stability of Amino Acids and Their Oligomerization Under High-Pressure Conditions: Implications for Prebiotic Chemistry 査読有り

    Tsubasa Otake, Takashi Taniguchi, Yoshihiro Furukawa, Fumio Kawamura, Hiromoto Nakazawa, Takeshi Kakegawa

    ASTROBIOLOGY 11 (8) 799-813 2011年10月

    出版者・発行元:MARY ANN LIEBERT INC

    DOI: 10.1089/ast.2011.0637  

    ISSN:1531-1074

    eISSN:1557-8070

    詳細を見る 詳細を閉じる

    The polymerization of amino acids leading to the formation of peptides and proteins is a significant problem for the origin of life. This problem stems from the instability of amino acids and the difficulty of their oligomerization in aqueous environments, such as seafloor hydrothermal systems. We investigated the stability of amino acids and their oligomerization reactions under high-temperature (180-400 degrees C) and high-pressure (1.0-5.5 GPa) conditions, based on the hypothesis that the polymerization of amino acids occurred in marine sediments during diagenesis and metamorphism, at convergent margins on early Earth. Our results show that the amino acids glycine and alanine are stabilized by high pressure. Oligomers up to pentamers were formed, which has never been reported for alanine in the absence of a catalyst. The yields of peptides at a given temperature and reaction time were higher under higher-pressure conditions. Elemental, infrared, and isotopic analyses of the reaction products indicated that deamination is a key degradation process for amino acids and peptides under high-pressure conditions. A possible NH(3)-rich environment in marine sediments on early Earth may have further stabilized amino acids and peptides by inhibiting their deamination.

  59. New silica clathrate minerals that are isostructural with natural gas hydrates 査読有り

    Koichi Momma, Takuji Ikeda, Katsumi Nishikubo, Naoki Takahashi, Chibune Honma, Masayuki Takada, Yoshihiro Furukawa, Toshiro Nagase, Yasuhiro Kudoh

    Nature Communications 2 196 2011年2月

    出版者・発行元:NATURE PUBLISHING GROUP

    DOI: 10.1038/ncomms1196  

    ISSN:2041-1723

    詳細を見る 詳細を閉じる

    Silica clathrate compounds (clathrasils) and clathrate hydrates are structurally analogous because both materials have framework structures with cage-like voids occupied by guest species. The following three structural types of clathrate hydrates are recognized in nature: cubic structure I (sI); cubic structure II (sII); and hexagonal structure H (sH). In contrast, only one naturally occurring silica clathrate mineral, melanophlogite (sI-type framework), has been found to date. Here, we report the discovery of two new silica clathrate minerals that are isostructural with sII and sH hydrates and contain hydrocarbon gases. Geological and mineralogical observations show that these silica clathrate minerals are traces of low-temperature hydrothermal systems at convergent plate margins, which are the sources of thermogenic natural gas hydrates. Given the widespread occurrence of submarine hydrocarbon seeps, silica clathrate minerals are likely to be found in a wide range of marine sediments.

  60. 隕石の海洋衝突による初期地球の有機物生成 招待有り 査読有り

    古川 善博, 関根 利守, 大庭 雅寛, 掛川 武, 中沢 弘基

    遊星人 18 (4) 223-237 2009年10月1日

  61. An interlaboratory study of TEX86 and BIT analysis using high-performance liquid chromatography–mass spectrometry 査読有り

    I, Schouten S. E, Hopmans C, van der Meer J, Mets A, Bard E, Bianchi T. S, Diefendorf A, Escala M, Freeman K. H, Furukawa Y, Huguet C, Ingalls A, Ménot-Combes G, Nederbragt A. J, Oba M, Pearson A, Pearson E. J, Rosell-Melé A, Schaeffer P, Shah S. R, Shanahan T. M, Smith R. W, Smittenberg R, Talbot H. M, Uchida M, Van Mooy, B. A. S, Yamamoto M, Zhang Z, Sinninghe Damsté J. S

    Geochemistry Geophysics Geosystems 10 Q03012 2009年3月

    出版者・発行元:None

    DOI: 10.1029/2008GC002221  

    ISSN:1525-2027

  62. Impact synthesis of organic compounds: Implication for their mass production on the early Earth 査読有り

    Furukawa Y, Sekine T, Oba M, Kakegawa T, Nakazawa H

    GEOCHIMICA ET COSMOCHIMICA ACTA 72 (12) A286-A286 2008年7月

    出版者・発行元:None

    ISSN:0016-7037

    eISSN:1872-9533

  63. Impact-generated ultrafine particles of olivine and serpentine suggesting a source of aerogels in the air of the early Earth 査読有り

    Furukawa Y, Kakegawa T, Sekine T, Nakazawa H

    GEOCHIMICA ET COSMOCHIMICA ACTA 71 (15) A300 2007年8月

    ISSN:0016-7037

  64. Formation of ultrafine particles from impact-generated supercritical water 査読有り

    Yoshihiro Furukawa, Hiromoto Nakazawa, Toshimori Sekine, Takeshi Kakegawa

    Earth and Planetary Science Letters 258 (3-4) 543-549 2007年6月

    出版者・発行元:ELSEVIER SCIENCE BV

    DOI: 10.1016/j.epsl.2007.04.014  

    ISSN:0012-821X

    詳細を見る 詳細を閉じる

    Shock-recovery experiments were performed targeting an olivine, iron, and water mixture to simulate a low-velocity ocean impact event. The maximum pressure in the sample container reached 20 GPa during the experiments. Ultrafine particles (UPs) of olivine and metal oxides were newly formed, even at pressures less than their vaporization pressure (150-200 GPa). Impedance-match and thermodynamic calculations suggest that supercritical water formed during the shock wave traversal. Such supercritical water dissolves impacted materials and precipitates Ups. Results of our experiments further suggest that many extraterrestrial objects that have impacted on oceans might have been converted to large masses of Ups and probably influenced the climate and UV shielding, especially during the late Hadean and early Archean eras. (c) 2007 Published by Elsevier B.V.

︎全件表示 ︎最初の5件までを表示

MISC 11

  1. 隕石からRNAの材料となる糖を検出

    古川善博

    化学 75 2020年

  2. 炭素同位体比測定によって確認された隕石に含まれる糖の存在

    古川善博

    Isotope News 771 32 2020年

  3. 衝撃波による鉱物,水,生体分子の相互作用:隕石衝突下のオリビンとアミノ酸水溶液の反応による粒子形状変化

    UMEDA Yuhei, FUKUNAGA Nao, SEKINE Toshimori, KOBAYASHI Takamichi, FURUKAWA Yoshihiro, KAKEGAWA Takeshi

    日本地球惑星科学連合大会予稿集(Web) 2016 2016年

  4. 【アストロバイオロジーとの遭遇:生命のルーツを探る旅】核酸の起源

    古川 善博

    細胞工学 35 (2) 107-110 2016年1月

    出版者・発行元:(株)学研メディカル秀潤社

    ISSN:0287-3796

  5. 隕石海洋衝突によるアラニンの化学進化に対する酸素分圧の効果

    梅田悠平, 関根利守, 古川善博, 掛川武, 小林敬道

    高圧討論会講演要旨集 55th 2014年

    ISSN:0917-6373

  6. 「月惑星探査の来たる10年:第二段階のまとめ」土星衛星エンセラダスのプリューム物質の化学・生命探査

    関根康人, 高野淑識, 矢野創, 矢野創, 船瀬龍, 高井研, 高井研, 石原盛男, 渋谷岳造, 橘省吾, 倉本圭, 薮田ひかる, 木村淳, 古川善博

    日本惑星科学会誌 遊・星・人 21 (3) 2012年

    ISSN:0918-273X

  7. 隕石の海洋衝突による初期地球の有機物生成

    古川 善博, 関根 利守, 大庭 雅寛, 掛川 武, 中沢 弘基

    遊・星・人 : 日本惑星科学会誌 18 (4) 226-237 2009年12月25日

    出版者・発行元:日本惑星科学会

    ISSN:0918-273X

    詳細を見る 詳細を閉じる

    生命の構成物質である,アミノ酸や核酸塩基,糖などの生物有機分子が生命誕生前の地球にどのように誕生したのかということは,生命起源解明の根幹を成す課題である.本稿では初期地球における隕石の海洋衝突による生物有機分子の生成について解説する.地球外物質の初期海洋への重爆撃は,後期重爆撃と呼ばれる38-40億年前に起きたと考えられている.著者らはこの現象を実験室で再現し,鉄,ニッケル,アモルファス炭素,水,窒素から有機物が生成するかどうかを明らかにするための衝突回収実験を行った.実験の結果,多種のカルボン酸,アミンおよびグリシンが生成することが明らかになった.この結果と衝突実験条件および有機物生成過程から隕石の後期重爆撃による生物有機分子の生成という,生命起源物質の新たな生成過程を示唆することとなった.

  8. Formation of ammonia and organic molecules by oceanic impact of meteorite

    Yoshihiro Furukawa

    Review of High Pressure Science and Technology/Koatsuryoku No Kagaku To Gijutsu 19 (3) 195-200 2009年

    DOI: 10.4131/jshpreview.19.195  

    ISSN:0917-639X 1348-1940

    詳細を見る 詳細を閉じる

    High-pressure and high-temperature reactions in meteorite impact events were subjected to extensive research in order to resolve origin of organic molecules on the early Earth. In this article, I introduce several researches of impact chemical reactions synthesizing ammonia and organic molecules on the early Earth. Atmosphere of the early Earth is thought to be slightly oxidized from which organic molecules are difficult to be synthesized. Several hypotheses related to impact synthesis of organic molecules have been proposed. Recently, ammonia and several organic molecules were synthesized demonstrating meteoritic impact reactions experimentally and umerically. Progress about the impact-induced chemical reactions will be able to reveal more clearly the origin of biomolecules on the early Earth.

  9. 11 初期地球ダイナミックスと生物有機分子の進化

    中沢 弘基, 掛川 武, 大原 祥平, 古川 善博

    Viva origino 32 (1) 12-12 2004年

    出版者・発行元:文部省科学研究費総合研究(B)「原始地球上における生命の起源に関する研究」班

    ISSN:0910-4003

  10. 13 続成作用温度圧力下でのアミノ酸の脱水重合 : 海洋堆積物内部における化学進化の可能性

    大原 祥平, 古川 善博, 掛川 武, 中沢 弘基

    Viva origino 32 (1) 14-14 2004年

    出版者・発行元:文部省科学研究費総合研究(B)「原始地球上における生命の起源に関する研究」班

    ISSN:0910-4003

  11. 12 グラファイトからのアミノ酸生成 : 初期海洋への隕石衝突と生物有機分子の起源

    古川 善博, 大原 祥平, 掛川 武, 中沢 弘基

    Viva origino 32 (1) 13-13 2004年

    出版者・発行元:文部省科学研究費総合研究(B)「原始地球上における生命の起源に関する研究」班

    ISSN:0910-4003

︎全件表示 ︎最初の5件までを表示

書籍等出版物 2

  1. Astrobiology

    Yoshihiro Furukawa

    Springer 2019年3月

  2. 地球科学の事典

    鳥海光弘, 他

    朝倉書店 2018年4月

講演・口頭発表等 21

  1. 宇宙での糖の生成と地球への運搬 招待有り

    日本分子生物学会 2020年12月4日

  2. Prebiotic Sugars on the Early Earth 国際会議 招待有り

    古川 善博

    Gordon Research Conference, Origin of life 2018年1月14日

  3. Sugar and its related compounds in space and on the erly Earth 国際会議 招待有り

    古川 善博

    Hayabusa symposium 2017 2017年12月

  4. 初期地球におけるRNA構成分子の生成と供給 招待有り

    古川 善博

    日本進化学会 2017年8月25日

  5. Borate 国際会議 招待有り

    古川 善博

    Gordon Research Conference, Origin of Life 2014年1月

  6. 隕石から見つかったリボース:その起源と生命 招待有り

    古川 善博

    GlycoTOKYOシンポジウム2022 2022年12月27日

  7. ホウ酸が駆動する前生物乾燥環境でのタンパク質生成 招待有り

    古川 善博

    日本分子生物学会 2022年12月1日

  8. Extraterrestrial ribose and other bioessential sugars identified in primitive meteorites 招待有り

    Yoshihiro Furukawa, Yoshito Chikaraishi, Naohiko Ohkouchi, Nanako Ogawa, Daniel P. Glavin, Jason P. Dworkin, Chiaki Abe, Tomoki Nakamura

    Pacifichem 2021 2021年12月21日

  9. Delivery of extraterrestrial ribose and other sugars by meteorites to prebiotic Earth 招待有り

    Yoshihiro Furukawa, Yoshito Chikaraishi, Naohiko Ohkouchi, Nanako Ogawa, Daniel P. Glavin, Jason P. Dworkin, Chiaki Abe, Tomoki Nakamura

    XIXth ISSOL conference 2021 2021年10月18日

  10. Amino acid formation by asteroid impacts on ammonia-free oceans 国際会議

    古川 善博

    XVIIIth International Conference on Origin of Life 2017 2017年7月16日

  11. Clay mineral assists borate to stabilize ribose 国際会議

    古川 善博

    Astrobiology Science Conference 2017 2017年6月26日

  12. Asteroid impacts as a source of life's building blocks on the early Earth. 国際会議

    古川 善博

    IGCP 630 Meeting 2017年6月14日

  13. Chiral changes of simple amino acids in early Earth’s ocean by meteorite impacts: Experimental simulations 国際会議

    Toshimori Sekine, Atsushi Takase, Yoshihiro Furukawa, Takeshi Kakegawa

    AGU 2012 Fall Meeting 2012年12月3日

  14. Effects of borate on the stability of ribose

    Furukawa Y, Horiuchi M, Kakegawa T

    有機地球化学シンポジウム 2012年8月22日

  15. バリンの衝突誘起キラリティー変換

    高瀬篤志, 関根利守, 掛川武, 小林敬道, 中沢弘基

    地球惑星科学連合大会 2012年5月20日

  16. 海洋衝突生成単純アミノ酸の衝突進化過

    梅田悠平, 福永奈央, 関根利守, 掛川武, 小林敬道, 中沢弘基

    地球惑星科学連合大会 2012年5月20日

  17. Effects of glycine and its decomposition products on polymerization of methionine under high temperature and pressure

    Huang R, Furukawa Y, Kakegawa T

    地球惑星科学連合大会 2012年5月20日

  18. Effects of salt on organic molecule formations by oceanic impacts on early Earth

    Suzuki C, Furukawa Y, Kobayashi T, Kakegawa T

    地球惑星科学連合大会 2012年5月20日

  19. 土星衛星エンセラダスのプリューム物質の化学・生命探査

    関根康人, 高野淑識, 矢野創, 高井研, 石原盛男, 渋谷岳造, 橘省吾, 倉本圭, 薮田ひかる, 木村淳, 古川善博, 田端誠

    地球惑星科学連合大会 2012年5月20日

  20. Effects of water content on the formation of reduced gases in impact

    Furukawa Y, Samejima T, Nakazawa H, Kakegawa T

    地球惑星科学連合大会 2012年5月20日

  21. Effects of borate on the stability of individual pentoses 国際会議

    Astrobiology Science Confeence 2012年4月16日

︎全件表示 ︎最初の5件までを表示

産業財産権 1

  1. アミノ酸の合成方法

    関根利守, 中澤弘基, 中澤暁, 掛川武, 古川善博, 大原祥平

    特許4288332

    産業財産権の種類: 特許権

共同研究・競争的資金等の研究課題 19

  1. 火星大気における炭素・窒素の進化と生命関連分子生成環境の研究

    寺田 直樹, 古川 善博, 黒田 剛史, 三宅 洋平, 関 華奈子, 青木 翔平, 横田 勝一郎, 倉本 圭

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:Tohoku University

    2022年4月1日 ~ 2027年3月31日

  2. 初期地球環境による生命材料分子の組み立て

    古川 善博, 伊藤 茜, 掛川 武

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:Tohoku University

    2022年4月1日 ~ 2026年3月31日

  3. 初期地球における特異的なリンの元素サイクルと前生物的代謝の成立

    掛川 武, 古川 善博, 石田 章純, 三村 耕一, 大藤 弘明

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:Tohoku University

    2022年4月1日 ~ 2025年3月31日

  4. 2次元ガスクロマトグラフ-安定同位体比質量分析計(GC-GC-IRMS)の開発

    力石 嘉人, 古川 善博, 滝沢 侑子

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:Hokkaido University

    2020年4月1日 ~ 2024年3月31日

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    本研究では,2次元ガスクロマトグラフ-安定同位体比質量分析計(GC-GC-IRMS)を開発する。その目的は,従来の1次元GC-IRMSを用いた測定において,長年の課題であった「GCでの厳格なピーク分離の要求」を抜本的に解決すること,そして,従来法では測定不可能であった多々の試料に関して,有機化合物の安定同位体比測定を可能にすることである。その達成は,生物から環境試料まで,試料中の全ての有機化合物について5W2H(Who, What, When, Where, Why, How, How many)に関する定性・定量的情報を獲得し,地球惑星科学の多様な研究,とくに (i) 生物の生合成・代謝系の機能の研究,(ii) 地球生物圏における有機物・エネルギー循環の研究,(iii) 宇宙空間や初期地球における有機物生成や生命の起源の研究などで,ブレイクスルーをもたらすと期待できる。 本年度(繰り越し期間を含む)は,購入したGC-GCモジュール」部を,研究代表者の研究室が現有している「GC-IRMS」と接続し,「GC-GC-IRMS」を組み立てた。また,有機化合物の安定同位体比の測定に向けて,(1) 接続部,ガスライン,キャピラリーラインの再設計や再配置,(2) 様々な条件(導入部の圧力・温度等のプログラム,GC部の温度プログラム,キャリアーガスの流速,溶媒の除去とIRMSへの接続のタイミングなど)に関して,様々な検証・最適化を実施した。これらの大部分は,当初,初年度に行う予定であったが,新型コロナウィルスの感染拡大防止措置のため実施が困難であっため,研究費の繰り越しを申請し,期間を延長して行った。 検証・最適化を行うなかで,「GC-GCモジュールと燃焼炉の間の温度制御の不安定性」が重要な課題であることがわかり,これを翌年の課題とした。

  5. 水が引き起こす化学進化-高分解能AFMによる前生物的RNA合成のその場観察-

    荒木 優希, 古川 善博

    2019年4月1日 ~ 2023年3月31日

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    2021年度は、マグネシウムイオンの存在下で粘土鉱物や炭酸カルシウム結晶表面へのヌクレオチドの吸着が顕著に増大することを周波数変調原子間力顕微鏡(FM-AFM)による液中その場観察から明らかにした。純水中ではマイカ、モンモリロナイト基板上へのヌクレオチドの吸着はほとんど見られなかったが、そこに塩化マグネシウム溶液を加えると基板表面が埋め尽くされるほど顕著にヌクレオチドの吸着が増大する様子が観察された。塩化カルシウム溶液を添加した場合にも吸着量は増大したが、マグネシウムほど顕著な変化は見られなかった。炭酸カルシウム結晶であるカルサイト基板表面においても同様で、塩化マグネシウム溶液添加後にヌクレオチドの吸着が観察された。カルサイト上では粘土のように表面全体を覆うほどの吸着は見られなかったが、これは両基板の表面電荷密度の違いに起因すると推測している。さらに、よりシンプルな分子構造を持った糖分子としてリボースを用いて同様の実験を行ったところ、やはりマグシウムイオンによる吸着量の増大が観察された。マグネシウムイオンの添加によってヌクレオチドの吸着が増大する理由について、本研究では基板表面の脱水和エネルギーが下がるためであると予測しており、カルサイト結晶上ではマグネシウムイオンにより水和構造が変化することを既に確認している。最終年度は実際にマグネシウムイオンによる粘土表面の水和構造・水密度がどのように変化するのかをFM-AFMによる固液界面その場観察により明らかにする。

  6. 隕石学および結晶成長学的戦略に基づいた尿路結石の分析手法の開発

    丸山 美帆子, 古川 善博, 門馬 綱一, 田中 勇太朗

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Challenging Research (Exploratory)

    研究種目:Challenging Research (Exploratory)

    研究機関:Osaka University

    2019年6月28日 ~ 2022年3月31日

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    結石を高精度で薄片化し、かつ試料が含有する結晶相や組織をできる限り損なわない薄片作製する手順を確立した。この薄片を偏光顕微鏡、および顕微フーリエ変換赤外分光法により分析することで、結石内部に含まれる結晶の相同定および組織の詳細観察が可能となった。シュウ酸カルシウム(CaOx)と強く相互作用するカルシウム結合タンパク質を中心に、9種類のタンパク質について蛍光免疫染色の条件を確立した。上記手法により15個のCaOx結石を薄片化し、特にCaOxと相互作用が強いと言われる3種類のタンパク質(オステオポンチン、カリグラニュリンA、プロトロンビン)について結晶組織に応じた遍在状況の可視化に成功した。

  7. 初期太陽系で生成した糖とそのキラリティー:生命構成分子の新たな起源の解明

    古川 善博, 大河内 直彦, 力石 嘉人

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:Tohoku University

    2018年4月1日 ~ 2021年3月31日

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    生命を構成する糖は、これまでに地球外や地球外物質からは見つかっていなかった。本研究では、生命を構成する糖を隕石から検出し、その糖が地球外由来であることを炭素安定同位体組成を用いて明らかにした。この成果は米国科学アカデミー紀要に発表し、国内外から多くの反響を得た。この糖が地球生命の糖と同じ鏡像異性体であるかが注目されるが、本研究ではその分析手法の開発に成功し、隕石糖の分析を進めた。また、隕石に含まれる糖の生成反応であるホルモース型反応が隕石有機物の主要生成反応であったことを、模擬実験で生成したアミノ酸と不溶性有機物の炭素同位体比分析から明らかにし、Science Advances誌に発表した。

  8. 初期地球物質が生命起源に果たした役割

    掛川 武, 古川 善博, 小林 敬道

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:Tohoku University

    2018年4月1日 ~ 2021年3月31日

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    初期地球における隕石衝突を模擬した有機分子生成実験を行なった。物質材料研究機構の一段式火薬銃を用いた実験では、13Cにラベリングされた炭酸と窒素を源にし、金属鉄、ニッケルや水との高圧高温反応を行なった。その結果、ホルムアルデヒド、各種アミノ酸、核酸塩基の生成に成功した。特にホルムアルデヒドは糖の起源に繋がる重要な分子であり、糖の起源にも迫れる成果が得られた。東北大学においても高温隕石衝突蒸発雲を模擬した実験を展開し、各種アミンやグリシンの生成に成功した。生成物は新規に購入した液体クロマトグラフィーで分析を行なった。さらに生成物の炭素窒素同位体測定を行い、隕石衝突環境での有機物生成反応経路の特定を行なった。その分析のためにガスクロマトグラフと質量分析計をつなぐインターフェースも新たに購入した。質量分析計の高真空に保つメインテナンスもこなった。これら一連の実験と分析によって、初期地球の隕石衝突イベントの重要性が改めて強調されることになった。生命起源の化学進化の中で重要なステップである、アミノ酸のペプチド(タンパク質)化の実験も行なった。高圧条件および高温蒸発条件で実験を展開し、DKPの生成を押さえながらグリシンの高重合体生成に成功した。次年度以降の継続実験を行うために高圧実験装置の改良もこなった。ペプチドとともに生命起源に重要なヌクレオチド(RNA)生成メカニズを解明するためにホウ酸に富んだ蒸発環境を模擬したホルモース反応実験も展開した。その結果、粘土鉱物存在下で今まで考えられていなかった非アルカリ性条件で、リボースの生成やリン酸化が促進されることがわかった。ホウ酸に富んだ環境での粘土鉱物の特性を調べるためにアメリカデスバレー周辺で野外調査、情報収拾を行なった。成果は国際学会などで発表する一方、英語論文として公表した。

  9. 炭素質隕石の有機分子分布イメージングへの挑戦

    古川 善博, 中村 智樹, 宇留野 晃, 三枝 大輔, 齋藤 律水

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Challenging Research (Exploratory)

    研究種目:Challenging Research (Exploratory)

    研究機関:Tohoku University

    2017年6月30日 ~ 2019年3月31日

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    本研究では隕石中に含まれる有機分子の分布をマイクロメーターの空間分解能で明らかにすることに挑戦した。有機分子の空間分布を明らかにするために、隕石を成形し、MALDIベースのイオン化によるイメージング質量分析計で隕石を測定を行なった。その結果、いくつかの有機物を示す質量についての分布図を得ることができた。数マイクロメートルスケールの有機物分布はこれまでの隕石研究では明らかになっておらず、隕石中の有機物が太陽系のどこでいつできたのかを明らかにするために役立つはずである。現在は得られた質量情報から分子の特定に向けて分析を継続している。

  10. 初期地球が作り組み立てた生体分子

    掛川 武, 古川 善博, 小林 敬道, 関根 利守, 谷口 尚

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:Tohoku University

    2015年4月1日 ~ 2018年3月31日

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    以下の3つの課題に焦点をあてて生命起源に関する鍵となる研究を行った。反応系1:初期地球における隕石海洋衝突模擬実験を行い、アミノ酸、核酸塩基など生体構成主要有機分子が生成されうることを実証した。反応系2:初期地球海底および蒸発堆積物内部を想定したリボースの生成、さらにリボースのヌクレオチド化を試みた。その結果リボースの選択的安定化やヌクレオチド生成に成功した。反応系3:海底堆積物内部を想定したアミノ酸高温高圧脱水重合実験を行い、メチオニンやアスパラギン酸を用いてタンパク質の「骨格」ペプチドの生成に成功した。これら成果は初期地球のダイナミックスが「組み立て」のに重要な役割を果たしたことを示す。

  11. 初期地球における核酸塩基の新たな起源の解明 競争的資金

    古川 善博, 小林 敬道, 関根 利守, 関根 利守

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Tohoku University

    2015年4月1日 ~ 2018年3月31日

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    本研究では生命誕生前の地球で頻繁に起こっていたと考えられる隕石の海洋衝突を実験室で模擬して、その現象で生成する生命に必須の有機物、特に核酸塩基の生成を検証した。核酸塩基は生命の遺伝情報の文字となる分子で生命の誕生に不可欠であるが、その生成過程は非常に限定されていた。本研究では、一段式火薬銃を用いて隕石衝突によって引き起こされる化学反応を模擬し、生命誕生前の地球への隕石の衝突によって地球上に存在した大量の二酸化炭素を炭素源として、海洋中のアンモニアを窒素源として数種類の核酸塩基と多種のアミノ酸が生成することを示した。

  12. 減圧するマグマ中での硫黄の固気液相間の分配関係:火山ガス組成の予測モデルの確立

    奥村 聡, 角野 浩史, 古川 善博, 石橋 秀巳

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

    研究種目:Grant-in-Aid for Challenging Exploratory Research

    研究機関:Tohoku University

    2015年4月1日 ~ 2017年3月31日

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    マグマ中の硫黄は水蒸気などと一緒に火山ガスとして地表へ放出され,大気組成や気候に大きな影響を与えている.そのため硫黄がガスとして大気へ放出されるのか,岩石中に固定されるのかを決定づけるマグマ中の硫黄の固気液相間の分配関係を決定することは,火山ガス組成の理解と予測には必要不可欠である.本研究ではマグマの上昇・減圧過程(1~900MPa/hの減圧速度)の再現実験を行った.その結果,高減圧速度下において水・硫黄の非平衡脱ガスによってマグマが酸化し硫化金属が分解することを発見した.この結果は,固気液相間の硫黄分配が減圧速度に依存し,火山ガス組成はマグマ減圧速度の違いによって変化しうることを意味する.

  13. 鉱物をテンプレートとした前生物的RNA生成への挑戦

    古川 善博, 掛川 武, 長瀬 敏郎

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

    研究種目:Grant-in-Aid for Challenging Exploratory Research

    研究機関:Tohoku University

    2015年4月1日 ~ 2017年3月31日

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    本研究では鉱物表面でのヌクレオチドの重合によるオリゴヌクレオチドの生成に挑戦した。テンプレート鉱物はジプサム、カルサイトを用い、4種類のヌクレオチドについて実験を行なった。その結果、一部の実験ではジプサム基盤、ガラス基盤で十数量体のオリゴヌクレオチドが生成した。しかし、再現性や基板による優位な差が確認されないことから、追加実験を行なっている。 また、ホウ酸とリン酸を含む鉱物であるルネバガイトが、ヌクレオシドをリン酸化してヌクレオチドの生成を可能にするということを示した研究はドイツの科学誌Angwandte Chemie International Editionに掲載され表紙にも選ばれた。

  14. 炭素質コンドライトおよび南極微小隕石の有機分子—鉱物イメージングによる地球外有機物の生成過程研究 競争的資金

    制度名:Contract Research

    2016年5月 ~ 2017年3月

  15. 初期地球環境が作り出した前生物的有機圏

    掛川 武, 古川 善博, 関根 利守

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:Tohoku University

    2012年5月31日 ~ 2015年3月31日

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    生命起源に関する前生物的有機分子生成実験を初期地球の情報を生かしながら取り組むことが本研究課題の目的である。具体的には初期地球環境で最も頻繁に起った鉱物・水反応(隕石衝突、海洋堆積物続成作用など)に着目し最新鋭の分析機器を導入し、本組織でしか行えない実験を行う。一段式火薬銃を用いた衝撃圧縮実験、ガスフローラインによる衝突蒸気雲再現実験、高圧炉によるペプチド生成実験、高アルカリ条件でのリボース生成実験を行った。その結果、多種アミノ酸、ペプチド、核酸塩基生成に成功した。リボースの選択的安定化にも成功した。生命起源研究の進展に寄与する重要な成果であった。

  16. 隕石の海洋衝突条件下でのキラル化学に基づく生物有機分子進化

    関根 利守, 古川 善博, 小林 敬道, 掛川 武

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

    研究種目:Grant-in-Aid for Challenging Exploratory Research

    研究機関:Hiroshima University

    2012年4月1日 ~ 2014年3月31日

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    最近の研究により,約40億年前の地球には既に海が存在し激しい隕石衝突が起っていたと考えられている。そのような環境では地球上の生命起源物質が生成されることを示す実験結果もあり,実際にその頃の地層に含まれる炭素の中には非生物的起源の炭素も見つかっている。生命起源物質ではアミノ酸は基本的な物質で,タンパク質を作るアミノ酸はL体のみである。このことに注目して、衝撃回収実験で得られた試料の分析から衝突でキラル反応がどうなるかを実験的に検討した。

  17. 衝突反応による隕石有機物の化学進化

    古川 善博

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)

    研究種目:Grant-in-Aid for Young Scientists (B)

    研究機関:Tohoku University

    2011年 ~ 2013年

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    隕石の衝突現象は隕石や衝突地点付近の有機物に化学反応を起こす駆動力となりうる。 本研究では、ギ酸やメチルアミンなどの単純な有機物が衝突により発生する衝撃波によって反応し、生命誕生に必要な有機物が生成するのかどうかを実験的に検証した。 その結果、タンパク質構成アミノ酸であるグリシンおよびアラニンと数種の非タンパク質構成アミノ酸およびアミンの生成を確認した。この結果は、隕石に含まれるアミノ酸の一部は衝突により合成されたものであることを示すものである。また、隕石の衝突は生命誕生前の地球で頻繁に起こっていた現象と考えられており、このような有機合成が生命の前駆物質を生み出した可能性がある。

  18. 隕石の海洋衝突により生成する生物有機分子の総合的解明

    古川 善博

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Research Activity start-up

    研究種目:Grant-in-Aid for Research Activity start-up

    研究機関:Tohoku University

    2009年 ~ 2010年

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    生命誕生前の地球において有機分子がいつどのようにして誕生したのかは未だ明らかになっていない。隕石衝突生成説は、Furukawa et al. 2009の模擬実験によりアミノ酸やカルボン酸の生成が示され、その重要性が明らかにされた。 本研究では、揮発性有機分子回収装置を開発し、衝突実験生成物の分析を行った。この結果、炭化水素、アルコールなど、多種類のVOC生成が確認された。この結果は、隕石衝突が生命誕生前の地球に実に多様な有機物を供給したことを示唆している。

  19. グラファイトからの有機物生成:初期地球隕石海洋衝突による生物有機分子生成研究

    古川 善博

    2007年 ~ 2008年

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    本研究は初期地球における隕石の海洋衝突による、生命起源有機分子の生成について、実験的アプローチにより検証を行い、その現象により可能な生成分子種、生成量を解明することを目的としている。昨年度は、隕石の海洋衝突の実験に成功し、隕石主要鉱物と水との反応を明らかにした。二年目の今年度はその技術を用い、無機炭素、鉄、ニッケル、水を原料とする初期地球における隕石の海洋衝突模擬実験による有機物の生成を明らかにすることを目的として研究を行った。この研究には回収試料の抽出手法の開発、それらの試料のLC/MSおよびGC/MSを用いた分析手法の開発が必要となった。これらの実験および開発を行い、カルボン酸、アミンおよびグリシン(アミノ酸の一種)の生成を明確に証明することができた。この研究により、はじめて、初期地球において利用可能な物質から隕石の海洋衝突現象により生物磯分子が生成することが示唆された。この研究成果の意義は大変大きく、Nature Geoscienceの1月号に掲載された。掲載後の社会的反響も大きく、日本の報道機関(NHK、朝日新聞、読売新聞、毎日新聞、日経新聞、時事通信、共同通信、ニュートン)のみならず、海外の報道機関(USA Today,Science News,New Scientist,Scientific American,Chemistry World,Discovery Channel等)によっても報道された。

︎全件表示 ︎最初の5件までを表示

メディア報道 23

  1. 「隕石衝突」でアミノ酸生成

    朝日新聞

    2020年6月

    メディア報道種別: 新聞・雑誌

  2. 生命材料の糖 隕石から発見

    日経新聞

    2019年11月

    メディア報道種別: 新聞・雑誌

  3. 隕石から糖の分子検出に成功

    NHK おはよう日本

    2019年11月

    メディア報道種別: テレビ・ラジオ番組

  4. Sugars found in meteorites

    BBC World News

    2019年11月

    メディア報道種別: テレビ・ラジオ番組

  5. 「DNAの起源 隕石衝突」実験成功 生命のもととなる物質生成

    毎日新聞

    2015年

    メディア報道種別: 新聞・雑誌

  6. Study suggests life created by asteroid collisions

    USA Today

    2008年

    メディア報道種別: 新聞・雑誌

  7. 有機分子は隕石衝突で生成

    NHK

    2008年

    メディア報道種別: テレビ・ラジオ番組

  8. Asteroid impacts gave crucial spark to early life

    Discovery Channel

    2008年

    メディア報道種別: インターネットメディア

  9. Rock and Roil: Meteorites Hitting Early Earth's Oceans May Have Helped Spawn Life

    Scientific American

    2008年

    メディア報道種別: 新聞・雑誌

  10. 隕石中の有機物を再現

    日経新聞

    2021年5月

    メディア報道種別: 新聞・雑誌

  11. 生命を探す 太陽系編

    読売新聞

    2021年4月11日

    メディア報道種別: 新聞・雑誌

  12. 地球に隕石衝突 アミノ酸生成か

    河北新報

    2020年6月

    メディア報道種別: 新聞・雑誌

  13. 隕石衝突でアミノ酸生成

    日経新聞

    2020年6月

    メディア報道種別: 新聞・雑誌

  14. First Detection of Sugars in Meteorites Give Clues to Origin of Lifes

    NBC

    2019年11月

    メディア報道種別: インターネットメディア

  15. First Detection of Sugars in Meteorites Give Clues to Origin of Lifes

    MORNIG STAR

    2019年11月

    メディア報道種別: インターネットメディア

  16. 隕石から生命に欠かせない糖発見

    テレビ朝日 報道ステーション

    2019年11月

    メディア報道種別: テレビ・ラジオ番組

  17. Astronomers Look Inside Meteorites and Find the Sugars Needed for Life

    DISCOVER MAGAZINE

    2019年11月

    メディア報道種別: 新聞・雑誌

  18. 科学における仮説とはなにか 仮説が世界を前へと進める

    BSフジ ガリレオX

    2019年5月

    メディア報道種別: テレビ・ラジオ番組

  19. 隕石衝突から「DNAの部品」 原始の海 再現し生成

    読売新聞

    2015年

    メディア報道種別: 新聞・雑誌

  20. 隕石衝突が生命の材料を生んだ?

    ニュートンプレス Newton

    2015年

    メディア報道種別: 新聞・雑誌

  21. 生命の起源は隕石衝突

    毎日新聞

    2008年

    メディア報道種別: 新聞・雑誌

  22. Meteorite splash kick-started life

    New Scientist

    2008年

    メディア報道種別: 新聞・雑誌

  23. Study suggests life created by asteroid collisions

    ABC NEWS

    2008年

    メディア報道種別: テレビ・ラジオ番組

︎全件表示 ︎最初の5件までを表示

その他 4

  1. 炭素質コンドライトおよび南極微小隕石の有機分子—鉱物イメージングによる地球外有機物の生成過程研究

    詳細を見る 詳細を閉じる

    イメージング質量顕微鏡を用いて炭素質隕石に含まれる有機物の分布を明らかにする。

  2. 初期地球におけるRNA構成物質の生成と重合

    詳細を見る 詳細を閉じる

    生命のRNAを構成するリボースや核酸塩基などの物質は初期地球の一般的な環境では生成や重合が難しいと考えられている。本研究では初期地球の様々な環境に対応した条件でこれらの生成を明らかにする。

  3. 高温高圧下での多環芳香族炭化水素の安定性に関する研究

    詳細を見る 詳細を閉じる

    高温高圧下での多環芳香族炭化水素の安定性と重合を明らかにすることにより地下深部での炭素循環に制約を与える

  4. 初期地球における隕石衝突による有機物の生成と分解

    詳細を見る 詳細を閉じる

    隕石の高速衝突では、隕石構成鉱物と初期地球の海洋、大気間での化学反応が起こることが知られている。本研究では初期地球に置けるこのような隕石の高速衝突がどのような有機物を生成したのかを明らかにする。