We analyzed the amino acid content of seven lunar regolith samples returned by the Apollo 16 and Apollo 17 missions and stored under NASA curation since collection using ultrahigh-performance liquid chromatography with fluorescence detection and time-of-flight mass spectrometry. Consistent with results from initial analyses shortly after collection in the 1970s, we observed amino acids at low concentrations in all of the curated samples, ranging from 0.2 parts-per-billion (ppb) to 42.7 ppb in hot-water extracts and 14.5-651.1 ppb in 6 M HCl acid-vapor-hydrolyzed, hot-water extracts. Amino acids identified in the Apollo soil extracts include glycine, D-and L-alanine, D-and L-aspartic acid, D-and L-glutamic acid, D-and L-serine, L-threonine, and L-valine, all of which had previously been detected in lunar samples, as well as several compounds not previously identified in lunar regoliths: alpha-aminoisobutyric acid (AIB), D-and L-b-amino-n-butyric acid (beta-ABA), DL-alpha-amino-n-butyric acid, gamma-amino-n-butyric acid, beta-alanine, and epsilon-amino-n-caproic acid. We observed an excess of the L enantiomer in most of the detected proteinogenic amino acids, but racemic alanine and racemic beta-ABA were present in some samples.
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机译:我们分析了由阿波罗16号和阿波罗17号任务返回并在NASA策展下存储的七个月球长石样本的氨基酸含量,这是因为使用了具有荧光检测和飞行时间质谱仪的超高效液相色谱仪进行收集。与1970年代收集后不久的初步分析结果一致,我们在所有精选样品中观察到了低浓度的氨基酸,热水提取物中的氨基酸含量从十亿分之0.2(ppb)到42.7 ppb,而14.5-651.1 ppb在6 M HCl酸-蒸汽水解的热水提取物中。在阿波罗土壤提取物中鉴定出的氨基酸包括甘氨酸,D-和L-丙氨酸,D-和L-天冬氨酸,D-和L-谷氨酸,D-和L-丝氨酸,L-苏氨酸和L-缬氨酸,所有这些先前都已在月球样品中检测到,以及先前在月球白垩纪中未发现的几种化合物:α-氨基异丁酸(AIB),D-和Lb-氨基-正丁酸(beta-ABA),DL- α-氨基-正丁酸,γ-氨基-正丁酸,β-丙氨酸和ε-氨基-正己酸。我们在大多数检测到的蛋白原氨基酸中观察到过量的L对映异构体,但在某些样品中存在外消旋丙氨酸和外消旋β-ABA。
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