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