Cytotoxic isoflavones from Erythrina indica

Bioassay-directed fractionation of the CH 2Cl 2–MeOH (1:1) extract of the stem bark of Erythrina indica, has resulted in the isolation of two new isoflavone derivatives named indicanines D and E together with 11 known compounds including: six isoflavones (genistein, wighteone, alpinumisoflavone, dimethylalpinumisoflavone, 8-prenyl erythrinin C, and erysenegalensein E), one cinnamate (erythrinassinate B), two pentacyclic triterpenes (oleanolic acid and erythrodiol), and two phytosterols (stigmasterol and its 3- O-β- d-glucopyranoside). The structures of the new compounds were elucidated by means of spectroscopic analysis. The in vitro cytocidal activity against KB cells of some of the isolated compounds is also reported. In addition to eleven known compounds including six isoflavones, one ester of ferulic acid, two pentacyclic triterpenes and two phytosterols, two isoflavone derivatives, named indicanines D and E, were isolated from the stem bark of E. indica. Their structures were determined by spectroscopic techniques. Some of the isolated compounds were also tested for their cytotoxicity activity against KB cell.