Abstract
An investigation on biologically active secondary metabolites from the stem bark of Mesua beccariana was carried out. A new cyclodione, mesuadione (1), along with several known constituents which are beccamarin (2), 2,5-dihydroxy-1,3,4-trimethoxy anthraquinone (3), 4-methoxy-1,3,5-trihydroxyanthraquinone (4), betulinic acid (5) and stigmasterol (6) were obtained from this ongoing research. Structures of these compounds were elucidated by extensive spectroscopic methods, including 1D and 2D-NMR, GC-MS, IR and UV techniques. Preliminary tests of the in vitro cytotoxic activities of all the isolated metabolites against a panel of human cancer cell lines Raji (lymphoma), SNU-1 (gastric carcinoma), K562 (erythroleukemia cells), LS-174T (colorectal adenocarcinoma), HeLa (cervical cells), SK-MEL-28 (malignant melanoma cells), NCI-H23 (lung adenocarcinoma), IMR-32 (neuroblastoma) and Hep-G2 (hepatocellular liver carcinoma) were carried out using an MTT assay. Mesuadione (1), beccamarin (2), betulinic acid (5) and stigmasterol (6) displayed strong inhibition of Raji cell proliferation, while the proliferation rate of SK-MEL-28 and HeLa were strongly inhibited by stigmasterol (6) and beccamarin (2), indicating these secondary metabolites could be anti-cancer lead compounds in drug discovery.
Highlights
Herbal plants are usually a primary source of medicines in many developing countries
The flowers are traditionally used in conditions like asthma, cough and fever, whereas the fresh flowers are useful in reducing itchiness and nausea
The quaternary carbons were predicted to be carbonyl carbons due to their downfield chemical shifts as well as the appearance of C=O absorptions in the IR spectrum. Both carbonyl carbons were assigned as C-2 and C-8 due to long range HMBC correlations of correlated to δ 35.0 (C-3) and correlates to δ 25.4 (C-4) protons with the former carbonyl and C-6 proton with the latter carbonyl group (Figure 2)
Summary
Herbal plants are usually a primary source of medicines in many developing countries. Different parts of Mesua species are traditionally used as folk medicine for treatment of dyspepsia, fever, renal diseases and even as a poultice [1]. Previous chemical investigations on this species have revealed their activities to be basically due to the presence in these plants of phloroglucinols, xanthones and neoflavonoids [3,4,5,6,7,8,9,10]. These reports and the traditional uses of the Mesua species have led us to investigate the cytotoxic activities of Mesua beccariana. A new cyclodione, mesuadione (1), along with several known constituents 2–6 (Figure 1) were obtained from this ongoing research. The details of their cytotoxic activities are described in this manuscript
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
