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

O-Peracetylated 1-(β-d-glucopyranosyl)-5-phenylbiuret was prepared in the reaction of O-peracetylated β-d-glucopyranosylisocyanate and phenylurea. The reaction of O-peracetylated N-β-d-glucopyranosylurea with phenylisocyanate furnished the corresponding 1-(β-d-glucopyranosyl)-3,5-diphenyl- as well as 3-(β-d-glucopyranosyl)-1,5-diphenyl biurets besides 1-(β-d-glucopyranosyl)-3-phenylurea. O-Peracetylated 1-(β-d-glucopyranosyl)-5-(β-d-glycopyranosyl)biurets were obtained in one-pot reactions of O-peracetylated β-d-glucopyranosylamine with OCNCOCl followed by a second glycopyranosylamine of β-d-gluco, β-d-galacto and β-d-xylo configurations. O-Acyl protected 1-(β-d-glucopyranosyl)-3-(β-d-glycopyranosylcarbonyl)ureas were obtained from the reaction of β-d-glucopyranosylisocyanate with C-(glycopyranosyl)formamides of β-d-gluco and β-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 α-amylase.