α-Amylase and α-Glucosidase Inhibitory Saponins from Polyscias fruticosa Leaves

Abstract EN

Three bisdesmosidic saponins 3-O-[β-D-glucopyranosyl-(1 → 4)-β-D-glucuronopyranosyl] oleanolic acid 28-O-β-D-glucopyranosyl ester (1), polyscioside D (2), and 3-O- { β -D-glucopyranosyl-(1 → 2)-[β-D-glucopyranosyl-(1 → 4)]-β-D- g l u c u r o n o p y r a n o s y l } oleanolic acid 28-O-β-D-glucopyranosyl-(1 → 2)-β-D-galactopyranosyl ester (3) were isolated from a methanol extract of Polyscias fruticosa (L.) Harms leaves.

Compound 1 was obtained as a main constituent and compound 3 was reported for the first time and named as polyscioside I.

Saponin 1 inhibited porcine pancreas α-amylase and yeast α-glucosidase activities while 2 and 3 were inactive.

Synergistic inhibitory effect on α-amylase was observed from the combination of low concentrations of 1 and acarbose.

The findings suggest the use of P.

fruticosa and its major saponin 1 for the prevention and treatment of diabetes and its complications.