First report of steroid derivatives isolated from starfish Acanthaster planci with anti-bacterial, anti-cancer and anti-diabetic activities

Chemical studies on Acanthaster planci have afforded two steroids, 5 alpha-cholesta-24-en-3 beta,20 beta-diol-23-one (1) and 5 alpha-cholesta-9(11)-en-3 beta, 20 beta-diol (2). Structures compounds 1 and 2 were determined with the help of spectroscopic studies. Compound 1 showed strong antibacterial activity (21.0 +/- 0.06 mm) against P. aeruginosa. Compounds 1 and 2 were also active against human breast carcinoma cells (MCF-7) with LC50 values of 49 +/- 1.6 and 57.5 +/- 1.5 mu g/ml, respectively. This bioactivity was comparable to the currently used anticancer agent, cisplatin (LC50 46 +/- 1.1 mu g/ml). Compounds 1 and 2 exhibited anti-alpha-glucosidase activity with IC50 values of 58 +/- 0.8 and 55 +/- 0.5 mu g/ml, respectively, whereas IC50 of Acarbose as a positive control was found to be 36 +/- 0.4 mu g/ml in our bioassay.