Polymerization Reactions Involving the Side Chains of α-L-Amino Acids

Article abstract of DOI:10.1021/ja00237a030

The feasibility of polymerizing naturally occurring α-L-amino acids via their side chains by bonds other than the amide bond was investigated.Poly(Pal-Hpr-ester) > was obtained by melt transesterification of N-Pal-Hpr-Me in the presence of aluminum isopropoxide as catalyst.M_n (8450) and M_w (15500) were determined by gel permeation chromatography relative to polystyrene standards.The tyrosine dipeptide Z-Tyr-Tyr-Hex was cyanylated at the tyrosine side chain hydroxyl groups to yield Z-Tyr-Tyr-Hex-dicyanate -3-(p-cyanatophenyl)-L-alanine hexyl ester>.By solution polymerization of equimolar quantities of Z-Tyr-Tyr-Hex and Z-Tyr-Tyr-Hex-dicyanate in tetrahydrofuran, poly(Z-Tyr-Tyr-Hex-iminocarbonate) imino<2-<1-(benzyloxy)fomamido>-1-oxotrimethylene>-p-phenylene>> was obtained with M_n = 11500 and M_w = 19500.The synthesis of such "pseudopoly(amino acids)", which may be regarded as structural analogues of conventional poly(amino acids), may be of interest in enzymology, immunology, pharmacology, and biotechnology (biomaterials for medical applications).