Abstract
A new isoflavonoid, excelsanone (2), was isolated from the ethyl acetate extract of Erythrina excelsa stem bark, together with three known compounds namely 6,8-diprenylgenistein (3), β-sitosterol (1) and sitosteryl-β-D-glucopyranoside (4). Their structures were elucidated using spectroscopic methods (HR-ESI-MS, NMR and IR) and by comparison with some literature data. The antioxidant activity of crude extracts and two isolated compounds was evaluated using free radical scavenging (DPPH) and Ferric Reducing Ability Power (FRAP) methods with catechin as standard. The results of the radical scavenging activity showed that excelsanone (2) has a moderate potential with an IC50 of 1.31 mg/ml. The cytotoxicity of compounds 2 and 3 as well as the ethyl acetate extract was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in two prostate cancer cell lines (DU145 and PC3). Excelsanone (2) induced a greater cytotoxicity in all tested cell lines, with a significant inhibition of DU145 cells growth in a concentration-dependent manner.
![](/cms/asset/d4942902-6131-43cd-8ada-8c065affdb40/gnpl_a_1495639_uf0001_c.jpg)
Acknowledgements
The authors are grateful to the Institute of Medical Research and Medicinal Plants Studies (IMPM) for providing some consumables. We also thank the pharmacognosy team of the University of Liège for undertaking the spectral analysis of compounds; and Professor Roman A. Blaheta (University Hospital Frankfurt) for his collaboration. We also gratefully acknowledge the financial support from Japan Society for the Promotion of Science Postdoctoral Fellowship awarded, through a travel grant (P16411) to Maurice D Awouafack at the Institute of Natural Medicine, University of Toyama.
Disclosure statement
No potential conflict of interest was reported by the authors.