Camptothecine, a potent eukaryotic topoisomerase inhibitor, is an important anticancer compound. The global demand for this compound was estimated to be $1 billion in 2003 and is only further expected to increase. Partly to meet the expected increase in demand, in the recent past, several efforts have been made to discover newer and alternative plant and fungal sources of
camptothecine. In this study we report a rich source of camptothecine and its natural derivatives, Pyrenacantha volubilis (Icacinaceae) fromthe eastern coast of peninsular India. Camptothecine and its derivativeswere analyzed using high performance liquid chromatography (HPLC) coupledwith electrospray mass spectrometry (ESI-MS) in all plant parts such as twigs, leaves, roots, seedling, ripened whole fruit, fruit coat, seed coat and cotyledons. Cotyledons and ripened whole fruits contained the highest amount of camptothecine (1.35% and 0.60% dryweight respectively). LC-MS and ESI-MS/MS analyses revealed besides camptothecine, other derivatives and precursors such as 10-hydroxycamptothecine, 9- ethoxycamptothecine, 20-deoxycamptothecine, deoxypumiloside, strictosidine and strictosamide. Pure camptothecine was isolated from fruits and structurally confirmed usingNMR. Seed extractswere found to be effective against breast cancer, ovarian, colon and carcinoma cell lines (with IC50 values of 4.0 μg/mL, 6.5 μg/mL, 25.0 μg/mL and 25.0 μg/mL respectively). We discuss the results in the context of exploring alternative sources of camptothecine.