NOVEL HYPOTENSIVE AGENTS, NIAZIMIN-A, NIAZIMIN-B, NIAZICIN-A AND NIAZICIN-B FROM MORINGA-OLEIFERA - ISOLATION OF FIRST NATURALLY-OCCURRING CARBAMATES

Two novel hypotensive carbamate glycosides designated niazimin A 1 and niazimin B 3 and two new hypotensive mustard oil glycosides possessin g the thiocarbamate group, niazicin A 5 and niazicin B 10 along with a benzaldehyde;glycoside 12 have been isolated from the fresh leaves ex tract of Moringa oleifera employing bioassay-guided fractionation. The structures of all these glycosides have been elucidated on the basis of spectroscopic evidence (IR. UV. MS, NMR. 2D NMR) and chemical react ions. Compounds 1 and 3 appear to be the first natural products embody ing the carbamate moiety. The amide bond in these compounds appears to play an important role in the hypotensive activity, since in both the carbamates and thiocarbamates it is common to those which possess hyp otensive activity.