| Abstract | Bioassay-guided phytochemical investigation of Sarcococca hookeriana has resulted in the isolation and structure elucidation of five new pregnane-type steroidal alkaloids: (-)- hookerianamide A (=(2β,3β,4β,20 S )-20- (dimethylamino)-3-[(3-methylbut-2-enoyl)amino]-5α-pregn-16- ene-2,4-diol; 1), (+)-hookerianamide B (=(2α,3β,4β,20 S )-4-acetoxy-20- (dimethylamino)-3-[(3-methylbut-2-enoyl)amino]-5α-pregnan-2- ol; 2), (-)-hookerianamide C (=(2β,3β,20 S )-2- acetoxy-20-(dimethylamino)-3-[(3-methylbut-2-enoyl)amino]-5α- pregnane; 3), (-)-hookerianamine A (=(3β,20 S )-20- (dimethylamino)-3-(methylamino)-5α-pregn-14-ene; 4), and (+)- phulchowkiamide A (=(3β,20 S )-20-(methylamino)-3-[(2- methylbut-2-enoyl)amino]-5α-pregn-2-en-4-one; 5). These compounds, as well as the two chemically derived acetyl derivatives 6 and 7, displayed cholinesterase inhibition in a concentration-dependent manner. |