@article{5cfabf72ab7c448a957ac5d46fc7e668,
title = "Extraterrestrial hydroxy amino acids in CM and CR carbonaceous chondrites",
abstract = "The abundances, distributions, and enantiomeric ratios of a family of three- and four-carbon hydroxy amino acids (HAAs) were investigated in extracts of five CM and four CR carbonaceous chondrites by gas chromatography-mass spectrometry analyses. HAAs were detected in both the acid hydrolysates of the hot water extracts and the 6 M HCl extracts of all the CM and CR chondrites analyzed here with total hot water and HCl extractable HAA concentrations ranging from 6.94 to 315 nmol g−1. The HAA analyses performed in this study revealed: (1) the combined (hot water + HCl) extracts of CR2 chondrites contained greater abundances of α-HAAs than that of CM2 chondrites and (2) the combined extracts of CM and CR chondrites contained roughly similar abundances of β- and γ-HAAs. Application of the new GC-MS method developed here resulted in the first successful chromatographic resolution of the enantiomers of an α-dialkyl HAA, d,l-α-methylserine, in carbonaceous chondrite extracts. Meteoritic α-methylserine was found to be mostly racemic within error and did not show l-enantiomeric excesses correlating with the degree of aqueous alteration, a phenomenon observed in meteoritic isovaline, another α-dialkyl amino acid. The HAAs identified in CM and CR chondrite extracts could have been produced during parent body alteration from the Strecker cyanohydrin reaction (for α-HAAs) and an ammonia-involved formose-like reaction (for β-, and γ-HAAs).",
author = "Toshiki Koga and Parker, {Eric T.} and McLain, {Hannah L.} and Aponte, {Jos{\'e} C.} and Elsila, {Jamie E.} and Dworkin, {Jason P.} and Glavin, {Daniel P.} and Hiroshi Naraoka",
note = "Funding Information: This work was supported by the JSPS Overseas Challenge Program for Young Researchers Grant (number 201880018), the NASA Astrobiology Institute through award 13-13NAI7-0032 to the Goddard Center for Astrobiology, and a grant from the Simons Foundation (SCOL award 302497 to J.P.D.). We thank the National Institute of Polar Research and the Antarctic meteorite curator at the NASA Johnson Space Center for providing the meteorite samples used in this study. US Antarctic meteorite samples were recovered by the Antarctic Search for Meteorites (ANSMET) program which has been funded by NSF and NASA and characterized and curated by the Department of Mineral Sciences of the Smithsonian Institution and the Astromaterials Curation Office at the NASA Johnson Space Center. Japanese Antarctic meteorite samples were provided by the National Institute of Polar Research (NIPR). We appreciate valuable comments on the manuscript from two anonymous reviewers. The authors declare no conflicts of interest. Funding Information: This work was supported by the JSPS Overseas Challenge Program for Young Researchers Grant (number 201880018), the NASA Astrobiology Institute through award 13‐13NAI7‐0032 to the Goddard Center for Astrobiology, and a grant from the Simons Foundation (SCOL award 302497 to J.P.D.). We thank the National Institute of Polar Research and the Antarctic meteorite curator at the NASA Johnson Space Center for providing the meteorite samples used in this study. US Antarctic meteorite samples were recovered by the Antarctic Search for Meteorites (ANSMET) program which has been funded by NSF and NASA and characterized and curated by the Department of Mineral Sciences of the Smithsonian Institution and the Astromaterials Curation Office at the NASA Johnson Space Center. Japanese Antarctic meteorite samples were provided by the National Institute of Polar Research (NIPR). We appreciate valuable comments on the manuscript from two anonymous reviewers. The authors declare no conflicts of interest. Publisher Copyright: {\textcopyright} 2021 The Meteoritical Society.",
year = "2021",
month = may,
doi = "10.1111/maps.13661",
language = "English",
volume = "56",
pages = "1005--1023",
journal = "Meteoritics and Planetary Science",
issn = "1086-9379",
publisher = "The University of Arkansas Press",
number = "5",
}