Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.
Astromaterials Research and Exploration Science, NASA Johnson Space Center, 2101 NASA Parkway, Houston, TX 77058, USA.
Sci Adv. 2017 Mar 17;3(3):e1602093. doi: 10.1126/sciadv.1602093. eCollection 2017 Mar.
The exogenous delivery of organic molecules could have played an important role in the emergence of life on the early Earth. Carbonaceous chondrites are known to contain indigenous amino acids as well as various organic compounds and complex macromolecular materials, such as the so-called insoluble organic matter (IOM), but the origins of the organic matter are still subject to debate. We report that the water-soluble amino acid precursors are synthesized from formaldehyde, glycolaldehyde, and ammonia with the presence of liquid water, simultaneously with macromolecular organic solids similar to the chondritic IOM. Amino acid products from hydrothermal experiments after acid hydrolysis include α-, β-, and γ-amino acids up to five carbons, for which relative abundances are similar to those extracted from carbonaceous chondrites. One-pot aqueous processing from simple ubiquitous molecules can thus produce a wide variety of meteoritic organic matter from amino acid precursors to macromolecular IOM in chondrite parent bodies.
外源有机分子的输送可能在早期地球上生命的出现中发挥了重要作用。碳质球粒陨石被认为含有土著氨基酸以及各种有机化合物和复杂的大分子材料，如所谓的不溶性有机质（IOM），但有机质的起源仍存在争议。我们报告说，在液态水存在的情况下，甲醛、乙二醇醛和氨可以合成水溶性氨基酸前体，同时还可以合成类似于球粒陨石 IOM 的大分子有机固体。水热实验后的酸水解氨基酸产物包括α-、β-和γ-氨基酸，最多含有五个碳原子，其相对丰度与从碳质球粒陨石中提取的相似。因此，从简单普遍存在的分子一锅法水相处理可以从氨基酸前体到球粒陨石母体中的大分子 IOM 产生各种各样的陨石有机质。
