Structure-activity relationship of highly potent galactonoamidine inhibitors toward β-galactosidase (Aspergillus oryzae).

A small library of 22 N-substituted galactonoamidines was synthesized, and their structure-activity relationship for inhibition of the hydrolytic activity of β-galactosidase (Aspergillus oryzae) was evaluated. A fast screening assay in 96-well plate format was used to follow the enzymatic hydrolysis of 2-chloro-4-nitrophenyl-β-D-galactopyranoside using UV-vis spectroscopy. The aglycon moiety of all compounds was found to have a profound effect on their inhibitory ability.