Two new polyhydroxylated steroids, 3β-acetoxy-gorgost-5α,6β,11α-triol (3) and (23 R) methylergosta-20-ene-3β,5α,6β,17α-tetrol (4), together with three known gorgosteroid compounds, gorgost-3β, 5α,6β,11α- tetrol (1), 11α-acetoxy-gorgost- 3β,5α, 6β- triol (2), and gorgost-5 (E) ene-3-β-ol (5), as well as batyl alcohol (6), were isolated from the Egyptian soft coral Heteroxenia fuscescens. The structures of these compounds were elucidated based on NMR spectroscopic analyses, HR-FAB-MS, and comparisons with published data. The cytotoxic activities of the fractions and compounds were evaluated against MCF-7 cancer cell lines using MTT colorimetric assay. Compounds 2 and 4 showed moderate cytotoxic activity, with IC50 values equal to 33.2 and 25.1 µM, respectively, in comparison with the IC50 of 5-fluorouracil 18.7 µM.
Keywords: MCF-7; Polyhydroxylated; cytotoxicity; heteroxenia.