Cholinesterase-inhibiting new steroidal alkaloids from Sarcococca hookeriana of Nepalese origin

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