HYDROTHERMAL SYNTHESIS OF AMINO-ACIDS

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 NH4HCO3 solutions were reacted with C2H2, H-2, and O2 (formed in situ from CaC2, Ca, and H2O2) at 200-275-degrees-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-degrees-C. Amino acids and amines also were synthesized at 210-degrees-C from solutions of NH4OH, HCHO, NaCN, and H-2. When NH4OH was replaced by NH4HCO3, the syntheses predominantly confirmed the recent results of HENNET et al. (1992). Additionally, amino acids and amines were observed to form by reactions among NH4OH, HCHO, and H-2 at hydrothermal conditions, essentially confirming the results of Fox and WINDSOR (1970). Inclusion of both carbonate and O2 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.