HYDROTHERMAL SYNTHESIS OF AMINO ACIDS

Abstract

This study presents further evidence that amino acids can be synthesized rapidly in hydrothermal solutions from reactants that may have been present in primitive environments. Aqueous NH 4 HCO 3 solutions were reacted with C 2 H 2 , H 2 , and O 2 (formed in situ from CaC 2 , Ca, and H 2 O 2 ) at 200-275°C over 0.2-2 h periods to synthesize several amino acids and abundant amines. These amino acid and amine producing reactions were not observed to occur below 150°C. Amino acids and amines also were synthesized at 210°C from solutions of NH 4 OH, HCHO, NaCN, and H 2 . When NH 4 OH was replaced by NH 4 HCO 3 , the syntheses predominantly confirmed the recent results of et al. (1992). Additionally, amino acids and amines were observed to form by reactions among NH 4 OH, HCHO, and H 2 at hydrothermal conditions, essentially confirming the results of and (1970). Inclusion of both carbonate and O 2 in these latter solutions greatly enhanced the production rate of amino acids. The amines synthesized hydrothermally could be significant if they are precursors in the amino acid syntheses either at hydrothermal or later at lower temperatures. These observations provide additional input to the current questions of synthesis, stability, and decomposition of amino acids at hydrothermal conditions, and their possible relevance to the origin of life.