Comprehensive Search of Stable Isomers of Alanine and Alanine Precursors in Prebiotic Syntheses
Comprehensive Search of Stable Isomers of Alanine and Alanine Precursors in Prebiotic Syntheses
复制标题
益生元合成中丙氨酸和丙氨酸前体稳定异构体的综合检索
DOI：
10.1089/ast.2022.0011
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发表时间：
2022
期刊：
影响因子：
4.2
通讯作者：
Shigeta Yasuteru
中科院分区：
文献类型：
--
作者：
Shoji Mitsuo;Watanabe Natsuki;Hori Yuta;Furuya Kenji;Umemura Masayuki;Boero Mauro;Shigeta Yasuteru
在陨石中发现了对映体过量的氨基酸，然而，它们的分子机制和益生元合成仍然是一个争论的问题。为了阐明同手性的起源，采用最小能量原理，即分子在星际介质中的迁移与异构体间的稳定性直接相关，研究了丙氨酸和在生命前体过程中形成的手性前体在异构体间的稳定性.为了便于搜索可能的异构体，我们开发了一种新的异构体搜索算法，随机连接方法，并进行了彻底的搜索所有稳定的异构体在一个给定的化学式。我们发现丙氨酸和它的大多数前体都位于比最稳定的直链结构异构体高出5.7 kcal mol−1的能量处，而只有2-氨基丙腈是所有可能的异构体中最稳定的异构体。α-氨基腈的固有稳定性表明，2-氨基丙腈是形成α-氨基酸的常见对映体过量的主要贡献。
Enantiomeric excesses ofl-amino acids have been detected in meteorites; however, their molecular mechanism and prebiotic syntheses are still a matter of debate. To elucidate the origin of homochirality, alanine and the chiral precursors formed in prebiotic processes were investigated with regard to their stabilities among their isomers by employing the minimum energy principle, namely, the abundancy of a molecule in the interstellar medium is directly correlated to the stability among isomers. To facilitate the search for possible isomers, we developed a new isomer search algorithm, the random connection method, and performed a thorough search for all the stable isomers within a given chemical formula. We found that alanine and most of its precursors are located at higher energy by more than 5.7 kcal mol−1, with respect to the most stable isomer that consists of a linear-chain structure, whereas only the 2-aminopropanenitrile is the most stable isomer among all others possible. The inherent stability of the α-amino nitrile suggests that the 2-aminopropanenitrile is the dominant contribution in the formation of the common enantiomeric excess over α-amino acids.