Orizabins V-VIII, tetrasaccharide glycolipids from the Mexican scammony root (Ipomoea orizabensis).

An extensive investigation of the so-called jalapin resinoid obtained from roots of the Mexican scammony, Ipomoea orizabensis, using high field NMR spectroscopy led to the characterization of six glycosides, including the known scammonins I (1) and II (2) and four new tetrasaccharides of jalapinolic acid, orizabins V-VIII (3-6). All the isolates (1-6) were found to be weakly cytotoxic toward human oral epidermoid carcinoma (KB).