Isolation of cytotoxic polyphenolic derivatives from the root bark of Mesua ferrea

Phytochemists nowadays have growing interests on medicinal plants which have pharmacological activities. Therefore, investigation on biological active secondary metabolites from the root bark of Mesua ferrea (Clusiaceae) was scrutinized. A series of polyphenolic derivatives were obtained from our ongoing research where three of which were new: mesuaferrin A 1, mesuaferrin B 2 and mesuaferrin C 3. The known compounds were identified as caloxanthone C 4, 1,5-dihydroxyxanthone 5 and tovopyrifolin C 6. Structures of these compounds were elucidated by extensive spectroscopic methods which include 1D and 2D-NMR, GC-MS and IR techniques. Preliminary insights on in vitro cytotoxicity and structure-activity relationships of all the isolated metabolites against a panel of human cancer cell lines including Raji (human B lymphocyte), SNU-1 (human gastric carcinoma), K562 (human erythroleukemia cells), LS-174T (human colorectal adenocarcinoma), HeLa (human cervical cells), SK-MEL-28 (human malignant melanoma cells), NCI-H23 (human lung adenocarcinoma), IMR-32 (human neuroblastoma) and Hep-G2 (human hepatocellular liver carcinoma) were performed using MTT assay. Compounds 1 - 5 exhibited significant (IC₅₀ values ranging from 0.1 to 9.4 µg/mL) cell proliferation inhibition against all the tested cancer cells. The phytochemical and pharmacognosy investigation showed adverse effects of polyphenolic compounds suggesting that Mesua ferrea could be a phytotheraupic source of lead compounds in drug discovery.