Synthesis of new glycosyl biuret and urea derivatives as potential glycoenzyme inhibitors

Abstract

O-peracetylated 1-(beta-D-glucopyranosyl)-5-phenylbiuret was prepared in the reaction of O-peracetylated beta-D-glucopyranosylisocyanate and phenylurea. The reaction of O-peracetylated N-beta-D-glucopyranosylurea with phenylisocyanate furnished the corresponding 1-(beta-D-glucopyranosyl)-3,5-diphenyl- as well as 3-(beta-D-glucopyranosyl)-1,5-diphenyl biurets besides 1-(beta-D-glucopyranosyl)-3-phenylurea. O-Peracetylated 1-(beta-D-glucopyranosyl)-5-(beta-D-glycopyranosyl)biurets were obtained in one-pot reactions of O-peracetylated beta-D-glucopyranosylamine with OCNCOCl followed by a second glycopyranosylamine of beta-D-gluco, beta-D-galacto and beta-D-xylo configurations. O-Acyl protected 1-(beta-D-glucopyranosyl)-3-(beta-D-glycopyranosylcarbonyl)ureas were obtained from the reaction of beta-D-glucopyranosylisocyanate with C-(glycopyranosyl)formamides of beta-D-gluco and beta-D-galacto configurations. The O-acyl protecting groups were removed under acid- or base-catalyzed transesterification conditions, except for the N-acylurea derivatives where the cleavage of the N-acyl groups was faster than deprotection. Some of the new compounds exhibited moderate inhibition against rabbit muscle glycogen phosphorylase b and human salivary alpha-amylase.