Aqueous polymerization of L-amino acid active esters in bicarbonate solution via Leuchs' anhydrides

Aqueous polymerization of p-nitrophenyl esters of proteinaceous alpha-amino acids is much more efficient in the presence of sodium hydrogen carbonate than in the presence of sodium hydroxide for a given pH. Evidence is presented for the intermediary formation of Leuchs' anhydride in the presence of bicarbonate anions. The prebiotic significance of such a mechanism favouring the polymerization of proteinaceous alpha-amino acids, i.e. C alpha-mono-substituted amino acid, is discussed.