期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2021
卷号：118
期号：22
页码：1
DOI：10.1073/pnas.2101314118
出版社：The National Academy of Sciences of the United States of America
摘要：Cell membranes are a key element of life because they keep the genetic material and metabolic machinery together. All present cell membranes are made of phospholipids, yet the nature of the first membranes and the origin of phospholipids are still under debate. We report here the presence of ethanolamine in space, N H 2 C H 2 C H 2 OH, which forms the hydrophilic head of the simplest and second-most-abundant phospholipid in membranes. The molecular column density of ethanolamine in interstellar space is N = (1.51 ± 0.07) × 10 13 c m − 2 , implying a molecular abundance with respect to H 2 of ( 0.9 − 1.4 ) × 10 − 10 . Previous studies reported its presence in meteoritic material, but they suggested that it is synthesized in the meteorite itself by decomposition of amino acids. However, we find that the proportion of the molecule with respect to water in the interstellar medium is similar to the one found in the meteorite ( 10 − 6 ). These results indicate that ethanolamine forms efficiently in space and, if delivered onto early Earth, could have contributed to the assembling and early evolution of primitive membranes.
