Thioester synthesis through geoelectrochemical CO2 fixation on Ni sulfides

• Published in: Communications chemistry Vol. 4; no. 1; p. 37
• Main Authors: Kitadai, Norio, Nakamura, Ryuhei, Yamamoto, Masahiro, Okada, Satoshi, Takahagi, Wataru, Nakano, Yuko, Takahashi, Yoshio, Takai, Ken, Oono, Yoshi
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17.03.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 639/638/161/886; 639/638/904; Carbon dioxide; Carbon monoxide; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Deep sea; Electrowinning; Fixation; Geoelectricity; Hydrothermal systems; Nickel sulfide; Prebiotics; Room temperature; Synthesis; Thioesters
• ISSN: 2399-3669; 2399-3669
• DOI: 10.1038/s42004-021-00475-5

A prevailing scenario of the origin of life postulates thioesters as key intermediates in protometabolism, but there is no experimental support for the prebiotic CO 2 fixation routes to thioesters. Here we demonstrate that, under a simulated geoelectrochemical condition in primordial ocean hydrothermal systems (–0.6 to –1.0 V versus the standard hydrogen electrode), nickel sulfide (NiS) gradually reduces to Ni 0 , while accumulating surface-bound carbon monoxide (CO) due to CO 2 electroreduction. The resultant partially reduced NiS realizes thioester (S-methyl thioacetate) formation from CO and methanethiol even at room temperature and neutral pH with the yield up to 35% based on CO. This thioester formation is not inhibited, or even improved, by 50:50 coprecipitation of NiS with FeS or CoS (the maximum yields; 27 or 56%, respectively). Such a simple thioester synthesis likely occurred in Hadean deep-sea vent environments, setting a stage for the autotrophic origin of life. Thioesters are often suggested to be key intermediates in primordial metabolism, but prebiotic CO 2 fixation routes to thioesters remain elusive. Here, the authors show nickel sulfide, partially reduced to Ni(0) with realistic geoelectric potentials, facilitates thioester (S-methyl thioacetate) formation via CO 2 -to-CO electroreduction, followed by a CO-methanethiol reaction.