Cytotoxic Activity of Two Cembranoid Diterpenes from Nicotiana Sylvestris Against Three Human Cancer Cell Lines

Abstract

Background: Two cembranoid diterpenes, [(1S, 2E, 4R, 6R, 7E, 11E)-2, 7, 11-cembratriene-4, 6-diol] (1) and its epimer [(1S, 2E, 4S, 6R,7E,11E)-2, 7, 11-cembratriene-4, 6-diol] (2) were isolated from surface dichloromethane washings and chloroform extract of Nicotiana sylvestris leaves. Methods: The compounds were purified using silica gel column- thin layer- and flash column chromatography methods. The structures of the isolated compounds were elucidated using spectroscopic analysis and their 1H and 13C NMR spectroscopic data were compared with those of authentic samples reported in the literature. The cytotoxic activity of 1 and 2 against three human cancer cell lines, including LS180 (human colon adenocarcinoma), MCF-7 (human breast adenocarcinoma) and MOLT-4 (human lymphoblastic leukemia) were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric bioassay. Results: The IC50 values of compounds 1 and 2 were calculated to be between (28.4±3.7 up to 44.0±6.4 µM) (mean±S.E.M.) for the above mentioned cell lines.