Alkaloids From Holarrhena, Kopsia And Tabernaemontana. Chemistry And Bioactivity.






Holarrhena curtisii, Kopsia griffithii, Tabernaemontana corymbosa, chemistry, alkaloids, bioactivity


Three Malaysian plants viz., Holarrhena curtisii, Kopsia griffithii and Tabernaemontana corymbosa were investigated for their alkaloidal content and the results are summarized below (Table and structures). A total of 98 alkaloids and 3 non-alkaloids were isolated and characterized from these three plants. Of these, 48 are new alkaloids and several represent first members of novel skeletal groups. All the 8 compounds from Holarrhena curtisii and 3 compounds from Kopsia griffithii viz., harmane 1, pleiocarpine 93 and buchtienine 114 showed significant activity against Leishmania donovani with the highest level of activity being shown by holamine 11 and buchtienine 114 (0.39 < IC50 < 1.56 µg/mL). The aminoglycosteroid, 17-epi-holacurtine 7 showed marked inhibition against HL-60 with IC50 0.01 µg/mL.. Three aspidofractinine compounds from Kopsia griffithii (pleiocarpine 93, 11-methoxykopsilongine 95 and kopsamine 98) and eighteen indole alkaloids from Tabernaemontana corymbosa (19S-hydroxyibogamine 262, coronaridine 268, heyneanine 276, 19-epi-heyneanine 277, dippinine B 280, dippinine C 281, apparicine 293, conodiparines A-D 306-309, conodutarines A-B 312-313, cononitarines A-B 314-315, 19'S-hydroxyconodurine 323, conodurinine 324 and 19'S-hydroxyconoduramine 325) showed appreciable activity in reversing multidrug resistance in vincristine-resistant KB cells with the highest level of activity shown by conodiparine A 305 (IC50 1.45 (µg/mL) and 11-methoxykopsilongine 95 (IC50 1.6µg/mL)