Scammonin III–VI, resin glycosides of Convolvulus scammonia

Abstract Four kinds of ether-soluble resin glycosides named scammonins III–VI were obtained as their acetates from Radix Scammoniae (scammony root), the root of Convolvulus scammonia . Their structures have been determined on the bases of chemical and spectral evidences. All of them have a common glycosidic acid, scammonic acid A, and a intramolecular macrocyclic ester structure.