Crude Drugs from Aquatic Plants. V. On the Constituents of Alismatis Rhizoma. (3). Stereostructures of Water-Soluble Bioactive Sesquiterpenes, Sulfoorientalols a, b, c, and d, from Chinese Alismatis Rhizoma

Abstract

From the water-soluble portion of Chinese Alismatis Rhizoma, four bioactive sesquiterpenes, sulfoorientalols a, b, c, and d, were isolated and their structures having a sulfonic acid function were established on the basis of chemical and physicochemical evidence. In addition, two sulfoorientalol congeners were derived from alismol by sulfonation of the exo-methylene moiety. Sulfoorientalols and the synthetic congeners were found to inhibt the carbachol-induced contraction of isolated bladder smooth muscle of guinea pig.