2,2-Diphenyl-1-picrylhydrazyl hydrate, a stable free radical, is an alpha-glucosidase inhibitor.

Glycosidases play a pivotal role in processing of various glycoproteins and glycolipids. It is well known that glycosidases are also involved in a variety of degenerative metabolic disorders such as cancer and AIDS. In order to develop potent alpha-glucosidase inhibitors, we first screened 2,2-diphenyl-1-picrylhydrazyl hydrate as a candidate. 2,2-Diphenyl-1-picrylhydrazyl hydrate was found to inhibit alpha- and beta-glucosidases as well as alpha- and beta-mannosidases. It was also shown to be a non-competitive inhibitor of yeast alpha-glucosidase with a Ki value of 1.1 x 10(-6) M. Taken together, we anticipate that 2,2-diphenyl-1-picrylhydrazyl hydrate may be a potent inhibitor for some incurable metabolic disorders including AIDS.