The hypoglycemic effect of (7R*,9aS*)-7-phenyl-octahydroquinolizin-2 one in mice

(-)-Multiflorine (1), which was isolated from leguminous plants, produced a hypoglycemic effect when administered to mice with streptozotocin-induced diabetes. (-)-Multiflorine has an enaminone type conjugation on the A-ring, which is unusual in lupine alkaloids, Proceeding on the assumption that th e A-B ring is responsible for the activity, several compounds bearing quino lizidin-2-one were synthesized and their hypoglycemic effects were examined , The hypoglycemic effect of (7R*,9aS*)-7-phenyl-octahydroquinolizin-2-one was approximately 4 times stronger than that of (-)-multiflorine measured b y oral glucose tolerance test in normal mice. This result indicates that co mpounds possessing the quinolizidin-2-one ring system as the basic structur e may be possible lead compounds for a new type of diabetes drug.