Isotopic analyses of amino acids from the Murchison meteorite.
Isotopic analyses of amino acids from the Murchison meteorite.
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DOI：
10.1016/0016-7037(91)90350-e
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发表时间：
1991-03
影响因子：
5
通讯作者：
S. Pizzarello;R. Krishnamurthy;Samuel Epstein;John R. Cronin
中科院分区：
文献类型：
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作者：
S. Pizzarello;R. Krishnamurthy;Samuel Epstein;John R. Cronin
先前对默奇森陨石总氨基酸的同位素分析表明，相对于陆地有机质，这些化合物的 2 H、 13 C 和 15 N 含量显着富集。这些分析已重复进行（2 H，13 C），其中包括超滤步骤，以排除细颗粒污染物携带先前工作中观察到的同位素过量的可能性。此外，对陨石氨基酸进行了色谱分离，以排除陨石提取物中同位素富集可能存在于氨基酸以外的碱性化合物中的可能性。结果表明默奇森氨基酸在同位素方面确实是不寻常的，同位素过量存在于至少几种不同的氨基酸中，并且其中一些氨基酸的同位素含量达到约+ 40%（δ 13 C）和+ 2500%（δD）。如果假设陨石α-氨基酸的高氘含量是其分子前体在星际云中通过低温离子分子反应合成的结果，那么它们在母体中通过水相Strecker反应形成与其一般特征和已知的母体过程一致。
Previous isotopic analyses of the total amino acids of the Murchison meteorite showed these compounds to be substantially enriched in 2 H, 13 C, and 15 N relative to terrestrial organic matter. These analyses have been repeated (2 H, 13 C) with inclusion of an ultrafiltration step to exclude the possibility that a fine paniculate contaminant carried the isotopic excesses observed in the previous work. In addition, the meteorite amino acids were chromatographically separated to rule out the possibility that the isotopic enrichment of the meteorite extract could reside in basic compounds other than amino acids. The results indicate that the Murchison amino acids are truly isotopically unusual, that the isotopic excesses reside in at least several different amino acids, and that the isotopic contents of some of these amino acids reach values of about+ 40%.(δ 13 C) and+ 2500%.(δD). If it is assumed that the high deuterium content of the meteorite α-amino acids is a result of the synthesis of their molecular precursors by low temperature ion-molecule reactions in an interstellar cloud, their formation by aqueous phase Strecker reactions in the parent body is consistent with their general characteristics and with known parent body processes.