title: The Abiotic Chemistry of Thiolated Acetate Derivatives and the Origin of Life.
abstract: Thioesters and thioacetic acid (TAA) have been invoked as key reagents for the origin of life as activated forms of acetate analogous to acetyl-CoA. These species could have served as high-energy group-transfer reagents and allowed carbon insertions to form higher molecular weight compounds such as pyruvate. The apparent antiquity of the Wood-Ljungdahl CO2 fixation pathway and its presence in organisms which inhabit hydrothermal (HT) environments has also led to suggestions that there may be a connection between the abiotic chemistry of compounds similar to TAA and the origins of metabolism. These compounds' apparent chemical simplicity has made their prebiotic availability assumed, however, although the kinetic behavior and thermochemical properties of TAA and analogous esters have been preliminarily explored in other contexts, the geochemical relevance of these compounds merits further evaluation. Therefore, the chemical behavior of the simplest thiolated acetic acid derivatives, TAA and methylthioacetate (MTA) were explored here. Using laboratory measurements, literature data, and thermochemical models, we examine the plausibility of the accumulation of these compounds in various geological settings. Due to the high free energy change of their hydrolysis and corresponding low equilibrium constants, it is unlikely that these species could have accumulated abiotically to any significant extant.
authors.affiliation: Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-IE-1 Ookayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Kuhan
authors.initials: K
authors.lastname: Chandru
authors.affiliation: Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-IE-1 Ookayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Alexis
authors.initials: A
authors.lastname: Gilbert
authors.affiliation: Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-IE-1 Ookayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Christopher
authors.initials: C
authors.lastname: Butch
authors.affiliation: Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-IE-1 Ookayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Aono
authors.affiliation: Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-IE-1 Ookayama, Meguro-ku, Tokyo 152-8551, Japan.|Institute for Advanced Study, Princeton, NJ 08540, USA.|Blue Marble Space Institute of Science, 1515 Gallatin St. NW, Washington, DC 20011, USA.|Center for Chemical Evolution, Georgia Institute of Technology, Atlanta, GA 30332 USA.
authors.forename: H James
authors.initials: HJ
authors.lastname: Cleaves
mesh_terms: D019342:Acetic Acid / Q000737:chemistry*; D000105:Acetyl Coenzyme A / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D005844:Geology; D007700:Kinetics; D000069497:Origin of Life; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry*
chemical_list: D013438:Sulfhydryl Compounds; D013440:Sulfides; D000105:Acetyl Coenzyme A; D002244:Carbon; C005732:thioacetic acid; D019342:Acetic Acid