Oxidative peptide (and amide) formation from Schiff base complexes.
One hypothesis of the origin of pre-modern forms of life is that the original replicating molecules were specific polypeptides which acted as templates for the assembly of poly-Schiff bases complementary to the template, and that these polymers were then oxidized to peptide linkages, probably by photo-produced oxidants. A double cycle of such anti-parallel complementary replication would yield the original peptide polymer. If this model were valid, the Schiff base between an N-acyl alpha amino aldehyde and an amino acid should yield a dipeptide in aqueous solution in the presence of an appropriate oxidant. In the present study it is shown that the substituted dipeptide, N-acetyl-tyrosyl-tyrosine, is produced in high yield in aqueous solution at pH 9 through the action of H2O2 on the Schiff-base complex between N-acetyl-tyrosinal and tyrosine and that a great variety of N-acyl amino acids are formed from amino acids and aliphatic aldehydes under similar conditions.
D000577:Amides / Q000138:chemical synthesis*; D000596:Amino Acids / Q000138:chemical synthesis; D005075:Biological Evolution; D006861:Hydrogen Peroxide; D007097:Imines; D010084:Oxidation-Reduction; D010455:Peptides / Q000138:chemical synthesis*; D012545:Schiff Bases / Q000138:chemical synthesis*; D014443:Tyrosine
D000577:Amides; D000596:Amino Acids; D007097:Imines; D010455:Peptides; D012545:Schiff Bases; D014443:Tyrosine; D006861:Hydrogen Peroxide