日本地球惑星科学連合2018年大会

講演情報

[EE] ポスター発表

セッション記号 B (地球生命科学) » B-AO 宇宙生物学・生命起源

[B-AO01] アストロバイオロジー

2018年5月22日(火) 13:45 〜 15:15 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:薮田 ひかる(広島大学大学院理学研究科地球惑星システム学専攻)、杉田 精司(東京大学大学院理学系研究科地球惑星科学専攻)、深川 美里(名古屋大学、共同)、藤島 皓介(東京工業大学地球生命研究所)

[BAO01-P03] Effect of Minerals on Amino Acids Formation in Environments Simulating Parent Bodies of Meteorites

*Walaa Elmasry1Shusuke Misawa1Jun Matsukuma1Yoko Kebukawa1Kensei Kobayashi1 (1.Yokohama National University)

キーワード:Meteorite, Formaldehyde, Minerals, Amino acids

The origin of life on Earth is not yet understood. Extraterrestrial organic compounds are considered as a key for understanding prebiotic organic synthesis in the early Earth. Several pathways have been proposed for the formation of extraterrestrial organic matters. Recently, Cody et al. [1] proposed the hypothesis that IOM and refractory organics in comets could be produced through the condensation of interstellar H2CO via formose reaction after planetesimal accretion, in the presence of liquid water in the early solar system. Additional hydrothermal experiments showed that ammonia enhanced the yields of organic matter [2] and produced amino acids [3]. The mineral surfaces could have been strongly involved throughout the process of synthesis of organic matter to contribute promoting prebiotic reactions. Pearson et al. [4] found that the meteoritic organic matter is strongly associated with clay minerals suggesting that clay mineral may have had an important catalytic role in chemical evolution in the early solar system.
In our present research, we are studying possible role that minerals such as montmorillonite clay and olivine could have played in the processes for the amino acid productions in water-bearing planetesimals.

First we synthesized organic compounds using a mixture of water, formaldehyde and ammonia (H2O, H2CO, NH3) in a ratio of 100:5:5 and 100:7:1 by simulating primordial materials in comets and asteroids, in order to compare between two ratios. Adding some minerals (10 g/L) to these solutions to study their effects on the formation of amino acids. Aqueous solutions were heated in oven under various temperatures (100 - 150°C). The resulting products were then acid hydrolyzed (6M HCl, 110°C, 24h), desalted, and subjected to amino acid analysis by high performance liquid chromatography (HPLC).

After acid hydrolysis, amino acids including glycine, alanine and beta-alanine were detected, while a little or no amino acids were detected without acid hydrolysis. Our preliminary results showed that the yields of amino acids were enhanced with the presence of minerals. These results suggested that the associated minerals were act as catalysts to produce amino acid precursors during aqueous activities in the planetesimals.


References:
[1] Cody et al. (2011) PNAS 108, 19171-19176.
[2] Kebukawa et al. (2013) ApJ 771, 19.
[3] Kebukawa et al. (2017) Science Advances 3, e1602093.
[4] Pearson et al. (2002) Meteoritics & Planetary Science 37, 1829-1833.