Synthesis of Amino Acids from Aldehydes and Ammonia: Implications for Organic Reactions in Carbonaceous Chondrite Parent Bodies
Synthesis of Amino Acids from Aldehydes and Ammonia: Implications for Organic Reactions in Carbonaceous Chondrite Parent Bodies
复制标题
由醛和氨合成氨基酸：对碳质球粒陨石母体有机反应的影响
DOI：
10.1021/acsearthspacechem.2c00008
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发表时间：
2022
影响因子：
3.4
通讯作者：
Naraoka Hiroshi
中科院分区：
文献类型：
--
作者：
Koga Toshiki;Naraoka Hiroshi
Strecker氰醇合成是从醛、氨和氰化物形成氨基酸的已知机制。氨基酸合成的另一种机制称为氨参与的类甲醛反应，使用醛和氨，它已被证明可以解释碳质陨石中的氨基酸分布。在本研究中，进行了从 13 C标记的醛和氨合成氨基酸的实验，并研究了类甲醛反应的详细形成途径。还检查了初始醛组成和游离氧对反应的影响。与氮气气氛中相比，空气中包括甘氨酸在内的氨基酸的产量显着增加，这表明空气中的氧气促进了氨基酸的合成。甘氨酸的前体化合物被鉴定为N-草酰甘氨酸，它可以由氨和乙醇醛氧化产生的乙醛酸合成。这种形成机制表明醛的氧化对于通过类甲糖反应合成氨基酸至关重要。根据甘氨酸通过N-草酰甘氨酸的形成途径，可以假设α-、β-和γ-含氧酸与氨反应，产生碳质球粒陨石中发现的氨基酸的各种结构异构体，包括α-、β-和γ-羟基氨基酸。
The Strecker cyanohydrin synthesis is a known mechanism for the formation of amino acids from aldehydes, ammonia, and cyanide. An alternative mechanism for amino acid synthesis called the ammonia-involved formose-like reaction uses aldehydes and ammonia, and it has been demonstrated to explain the amino acid distributions in carbonaceous meteorites. In this study, experiments were performed to synthesize amino acids from13C-labeled aldehydes and ammonia and to investigate the detailed formation pathways of the formose-like reaction. The effects of the initial aldehyde compositions and free oxygen on the reaction were also examined. The production of amino acids, including glycine, significantly increased in the air compared to in a nitrogen atmosphere, which indicates that oxygen in the air promotes amino acid synthesis. A precursor compound of glycine was identified asN-oxalylglycine, and it can be synthesized from ammonia and glyoxylic acid produced by the oxidation of glycolaldehyde. This formation mechanism indicates that the oxidation of aldehydes is crucial for amino acid synthesis by the formose-like reaction. Based on the formation pathway of glycine viaN-oxalylglycine, α-, β-, and γ-oxo acids can be hypothesized to react with ammonia to produce the various structural isomers of amino acids found in carbonaceous chondrites, including α-, β-, and γ-hydroxy amino acids.