text: Reaction of carbon monoxide (CO), hydrogen sulfide (HS) and methanethiol CHSH in the presence of nickel sulfide and iron sulfide generates the methyl thioester of acetic acid [CH-CO-SCH] and presumably thioacetic acid (CH-CO-SH) as the simplest activated acetic acid analogues of acetyl-CoA. These activated acetic acid derivatives serve as starting materials for subsequent exergonic synthetic steps. They also serve for energy coupling with endergonic reactions, notably the formation of (phospho)anhydride compounds. However, Huber and Wächtershäuser reported low 0.5% acetate yields based on the input of CHSH (methanethiol) (8 mM) in the presence of 350 mM CO. This is about 500 times and 3700 times  the highest CHSH and CO concentrations respectively measured to date in a natural hydrothermal vent  fluid.
  Reaction of nickel hydroxide with hydrogen cyanide (HCN) (in the presence or absence of ferrous hydroxide, hydrogen sulfide or methyl mercaptan) generates nickel cyanide, which reacts with carbon monoxide (CO) to generate pairs of α-hydroxy and α-amino acids: e.g. glycolate/glycine, lactate/alanine, glycerate/serine; as well as pyruvic acid in significant quantities. Pyruvic acid is also formed at high pressure and high temperature from CO, HO, FeS in the presence of nonyl mercaptan. Reaction of pyruvic acid or other α-keto acids with ammonia in the presence of ferrous hydroxide or in the presence of ferrous sulfide and hydrogen sulfide generates alanine or other α-amino acids. Reaction of α-amino acids in aqueous solution with COS or with CO and HS generates a peptide cycle wherein dipeptides, tripeptides etc. are formed and subsequently degraded via N-terminal hydantoin moieties and N-terminal urea moieties and subsequent cleavage of the N-terminal amino acid unit.
  Proposed reaction mechanism for reduction of CO on FeS: Ying et al. (2007) have shown that direct transformation of mackinawite (FeS) to pyrite (FeS) on reaction with HS till 300 °C is not possible without the presence of critical amount of oxidant. In the absence of any oxidant, FeS reacts with HS up to 300 °C to give pyrrhotite. Farid et al. have experimentally shown that mackinawite (FeS) has ability to reduce CO to CO at temperature higher than 300 °C. They reported that the surface of FeS is oxidized, which on reaction with HS gives pyrite (FeS). It is expected that CO reacts with HO in the Drobner experiment to give H.