Partial transfer of enantioselective chiralities from α-methylated amino acids, known to be of meteoritic origin, into normal amino acids

There is overwhelming evidence that meteorites bring α-methylated amino acids to earth with some l(S) enantiomeric excess. How does that get transferred into normal biological molecules? In this brief account, we show that an α-methylated amino acid, d(R)-α-methylvaline, can react with pyruvate and phenylpyruvate salts in dry mixtures to form alanine and phenylalanine with l enantiomeric excesses, under sensible prebiotic conditions. Thus the meteoritic l(S) excesses of this compound would produce excess d-alanine and d-phenylalanine, which are found in some organisms.