ABSTRACT
Background Neem (Azadirachta indica A. Juss) is a plant belonging to the meliaceae family. It was used widely asherbal medicine in ancient India and Burma. It possesses a variety of chemical constitutes. Recent studies showedthat some of major constitutes have remarkable anticancer activities. However, the minor constitutes in neem arestill studied insufficiently.Aim The aim of the study is to identify the minor constitutes in neem, and investigate their cytotoxic activity.Material & methods The dry seeds of neem were extracted with 95% ethanol. The ethyl acetate fraction of theextract was systematically separated by silica gel, Sephadex LH-20, High Performance Liquid Chromatography(HPLC) and other chromatographic techniques. The structures of the resulting isolates were elucidated byspectroscopic methods, such as mass spectrum (MS), nuclear magnetic resonance spectrum (NMR), etc.Results A sesquiterpenoid, 11,13-dihydroqinghaosu V (1), together with two known steroids, (24R)-ergosta5,7,22E-trien-3β-ol (2) and 5α,8α-epidioxiergosta-6,22-dien-3β-ol (3), was isolated from the dry seeds of neem. 1is a compound which is isolated from nature for the first time. In vitro cytotoxic bioassays showed that compound1 selectively inhibited the growth of Hela cell lines, with an IC50 value of 37.26 ±6.02 µM.Conclusion The study indicated that besides some major constituents of neem possessing anticancer activity, itsminor metabolites may also inhibit growth of cancer cells