FAGOMINE ISOMERS AND GLYCOSIDES FROM XANTHOCERCIS-ZAMBESIACA

50% aqueous MeOH extracts from the leaves and roots of Xanthocercis za mbesiaca (Leguminosae) were subjected to various ion-exchange column c hromatographic steps to give fagomine (1), 3-epi-fagomine (2), 3,4-di- epi-fagomine (3), 3-O-beta-D-glucopyranosylfagomine (4), and 4-0-beta- D-glucopyranosylfagomine (5). Their structures were determined by spec troscopic analyses, particularly by extensive 1D and 2D NMR studies. C ompounds 3 and 4 are new natural products. Compound 1 is a good inhibi tor of isomaltase and certain alpha- and beta-galactosidases. Whereas 2 is a more potent inhibitor of isomaltase and beta-galactosidases tha n 1, it does not inhibit alpha-galactosidase. Compounds 3-5 exhibited no significant inhibition against the glycosidases used.