Alkaloids from Ochrosia borbonica

Ten new monoterpenoid indole alkaloids, ochroborines A and B (1 and 2, resp.), 10‐hydroxyisovallesiachotamine (3), 10‐hydroxyisositsirikine (4), 10,11‐dimethoxysitsirikine (5), 10‐methoxyapoyohimbine (6), 10‐hydroxyakuammidine (7), akuammidine 17‐O‐β‐D‐glucoside (8), 15α‐hydroxyapparicine (9), and 15α‐hydroxy‐10‐methoxyapparicine (10), and 24 known alkaloids were isolated from leaves and twigs of Ochrosia borbonica J. F.Gmel. These structures were elucidated based on 1D‐ and 2D‐NMR, FT‐IR, UV, and MS data. 10‐Hydroxyisovallesiachotamine (3), ellipticine, and 10‐methoxyellipticine showed cytotoxic activities against five human cancer cell lines.