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 (=(2 β ,3 β ,4 β ,20 S )‐20‐(dimethylamino)‐3‐[(3‐methylbut‐2‐enoyl)amino]‐5 α ‐pregn‐16‐ene‐2,4‐diol; 1 ), (+)‐hookerianamide B (=(2 α ,3 β ,4 β ,20 S )‐4‐acetoxy‐20‐(dimethylamino)‐3‐[(3‐methylbut‐2‐enoyl)amino]‐5 α ‐pregnan‐2‐ol; 2 ), (−)‐hookerianamide C (=(2 β ,3 β ,20 S )‐2‐acetoxy‐20‐(dimethylamino)‐3‐[(3‐methylbut‐2‐enoyl)amino]‐5 α ‐pregnane; 3 ), (−)‐hookerianamine A (=(3 β ,20 S )‐20‐(dimethylamino)‐3‐(methylamino)‐5 α ‐pregn‐14‐ene; 4 ), and (+)‐phulchowkiamide A (=(3 β ,20 S )‐20‐(methylamino)‐3‐[(2‐methylbut‐2‐enoyl)amino]‐5 α ‐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.