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Hokkaido University Collection of Scholarly and Academic Papers >
Institute of Low Temperature Science >
低温科学 = Low Temperature Science >
第66巻 >
星間での複雑有機物の生成と変成 : 生命の素材は宇宙でつくられた
| Title: | 星間での複雑有機物の生成と変成 : 生命の素材は宇宙でつくられた |
| Other Titles: | Formation and Alteration of Complex Organic Compounds in Interstellar Space |
| Authors: | 小林, 憲正1 Browse this author | | 遠西, 寿子2 Browse this author | | 坪井, 大樹3 Browse this author | | 酒井, 貴博4 Browse this author | | 金子, 竹男5 Browse this author | | 吉田, 聡6 Browse this author | | 高野, 淑識7 Browse this author | | 高橋, 淳一8 Browse this author |
| Authors(alt): | Kobayashi, Kensei1 | | Tonishi, Hisako2 | | Tsuboi, Taiki3 | | Sakai, Takahiro4 | | Kaneko, Takeo5 | | Yoshida, Satoshi6 | | Takano, Yoshinori7 | | Takahashi, Jun-ichi8 |
| Issue Date: | 31-Mar-2008 |
| Publisher: | 北海道大学低温科学研究所 |
| Journal Title: | 低温科学 |
| Journal Title(alt): | Low Temperature Science |
| Volume: | 66 |
| Start Page: | 39 |
| End Page: | 46 |
| Abstract: | 炭素質コンドライトや彗星中に種々の複雑有機物が検出されていることから，地球外有機物が生命の誕生に重要な役割を果たした可能性が議論されている．隕石・彗星中有機物の起源としては，分子雲中の星間塵アイスマントル中で宇宙線・紫外線エネルギーにより生成したとするモデルが提案されて
いる．われわれは模擬星間物質に重粒子線を照射することにより高分子状の複雑有機物に結合したアミノ酸前駆体が生成することを見いだした．このような高分子状結合型アミノ酸は遊離アミノ酸と比較して宇宙環境で安定であること，円偏光照射によりアミノ酸エナンチオ過剰を生じうることなどが
わかった．これらの知見をもとに生命の起源にいたる新たな化学進化シナリオを提案する． | | Complex organic compounds were detected in carbonaceous chondrites and comets, and their relevance to origins of life has been discussed. It was suggested that these extraterrestrial organics were originally formed in ice mantles of interstellar dusts (ISDs) in molecular clouds. It was reported that amino acid precursors were formed from ice mixtures simulating ISD ice mantles by irradiation with UV or high-energy particles, but the nature of the precursors before hydrolysis were unknown. We irradiated a frozen mixture of possible interstellar molecules (methanol, ammonia and water) with high-energy heavy ions. The products were complex precursors of amino acids with large molecular weights. Such “complex amino acid precursors” were much more stable than free amino acids against irradiation with γ-rays or heavy ions. Irradiation of simulated interstellar complex organics with circular polarized light gave an enantiomeric excess of amino acid. These results suggested that formation of complex organics-bound amino acids and seeds of homochirality of amino acids were originally formed in interstellar cold environments. We propose a novel scenario of chemical evolution from interstellar organics to the first life on the Earth. |
| Description: | 1章 分子雲における氷と低温化学過程 |
| Type: | bulletin (article) |
| URI: | http://hdl.handle.net/2115/34708 |
| Appears in Collections: | 低温科学 = Low Temperature Science > 第66巻
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Submitter: 低温科学研究所図書室
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