Ester and amide derivatives of α-azaglycine (carbazic acid, H2NNHCOOH), α-azaalanine, and α-azaphenylalanine (ie, Ac-l-Phe-NHN (R) CO-X, where X= H, CH3, or CH2Ph, respectively) were synthesized and evaluated as inhibitors of the cysteine proteinases papain and cathepsin B. The ester derivatives inactivated papain and cathepsin B at rates which increased dramatically with leaving group hydrophobicity and electronegativity. For ...
