12:00 PM - 12:15 PM
[MTT28-12] Stereochemical feedback with “an achiral amino acid precursor” and “a chiral amino acid”: Experimental verifications
Keywords: “an achiral amino acid precursor” and “a chiral amino acid”, Stereochemical feedbacks
When we simply imagine a coin toss chemical reaction, prebiotic enantiomers are equally racemic outcomes as 50.0 : 50.0, likewise two sides of a coin. Among these racemic reactions (e.g., the typical nucleophilic substitution reaction), enantiomer-specific isotopic analysis (ESIA) showed infinitely homogeneous components for each enantiomer (Takano et al., 2010). D, L-alpha-alanine (C3 carbon frame; potentially, including D, L-alpha-alanine precursors: Takano et al., 2007) is most abundant chiral amino acid in prebiotic chemistry, except of glycine (C2). For further information of molecular-specific homochiral verification, here we developed a stereochemical feedback reaction with an “achiral amino acid precursor “ and “a chiral amino acid trigger”, resulting unique and large enantiomeric excesses in the reaction products. Here, we discuss the reaction mechanism focusing on an amino acid precursor formula and a transition state inducing optically active amino acids. This research was supported in part by a grant for Scientific Research on Innovative Areas (No. 25108001; A. Kouchi & H. Yurimoto) from the Japan Society for the Promotion of Science (JSPS).
Bassez, M-P., Takano, Y., and Ohkouchi, N. (2009) Organic analysis of peridotite rocks from Ashadze and Logatchev hydrothermal sites. International Journal of Molecular Sciences, 10, 2986-2998.
Bonner, W.A. (1991) The origin and amplification of biomolecular chirality. Origins of Life and Evolution of Biospheres, 21, 59-111.
Meierhenrich, U. (2008) Amino Acids and the Asymmetry of Life, Springer, 1-241.
Takano, Y., Takahashi, J., Kaneko, T., Marumo, K. and Kobayashi, K. (2007) Asymmetric synthesis of amino acid precursors in interstellar complex organics by circularly polarized light. Earth and Planetary Science Letters, 254, 106-117.
Takano, Y., Chikaraishi, Y., and Ohkouchi, N. (2010) Enantiomer-specific isotope analysis (ESIA) of D- and L-alanine: nitrogen isotopic hetero- and homogeneity by microbial process and chemical process. Earth, Life, and Isotopes. Kyoto University Press., pp. 387-402.