PAPAIN-CATALYZED ESTERIFICATION OF N-ALPHA-PROTECTED AMINO-ACIDS AND DIPEPTIDES WITH ETHANOL IN DIFFERENT ORGANIC-SYSTEMS

The papain-catalyzed esterification of N-alpha-protected amino acids a nd dipeptides with ethanol in mostly hydrophobic organic solvent syste ms containing low amounts of water has been investigated. The influenc e of various parameters, such as the amount of added water, reaction t ime, temperature and pH of added buffer, on the yield of ester was stu died first on the model substrate Z-Ala. The optimized reaction condit ions were then used for esterification of a series of N-alpha-protecte d amino acids and dipeptides.