A new isoflavonoid, excelsanone (2), was isolated from the ethyl acetate extract of Erythrina excelsa Backer stem bark, together with three known compounds namely 6,8diprenylgenistein (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 data reported in literature. 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 this radical scavenging activity showed that excelsanone (2) has a moderate potential with an IC 50 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.

Background: Dalbergia boehmii (Leguminosae), is a medicinal plant used in the Northen part of Cameroon, against digestive tract diseases and fever. Objectives: This work which is part of the search for bioactive molecules through natural products, aimed to isolate, characterize and evaluate the cytotoxicity of compounds from D. boehmii. Materials and Methods: Chemical investigations were carrying out on stem barks of Dalbergia boehmii using chromatographic techniques. Structures elucidation of isolated compounds were done using 1D and 2D NMR as well as EI-MS and literature data. Some isolated compounds were evaluated in vitro against MCF-7 cell lines for their cytotoxicity activity, using the MTT colorimetric method. Results: The chemical investigation leaded to the isolation of a new ceramide derivative named Dalbergiamide (1), a triterpene identified as olean-12-ene-3,11-dione (2) isolated here for the first time from Dalbergia genus, along with two known compounds, glucoside 3-O-β-D-sitosterol (3) and glucoside 3-O-β-D-stigmasterol (4). Compounds 1 and 2 were found to be cytotoxic at 50 μM with IC 50 value of 17.13 μM and 35.52 ± 2.95 μM respectively. Conclusion: These promising results suggested more in-depth studies should be carried out on this plant in order to assess its potential in the fight against cancer.