Steroid constituents from the soft coral Sinularia microspiculata

A methanol extract of the soft coral Sinularia microspiculata revealed five sterols, including two new compounds. Using combined chromatographic and spectroscopic experiments, the new compounds were found to be 7-oxogorgosterol (1) and 16α-hydroxysarcosterol (2). Their structures were determined on the basis of spectroscopic data (1H and 13C NMR, HSQC, HMBC, 1H-1H COSY, NOESY, and FT-ICR-MS) and by comparing obtained results to the values indicated in previous studies. Among the isolated compounds, 3 showed weak cytotoxic effects against HL-60 (IC50 = 89.02 ± 9.93 μM) cell line, whereas 5 was weakly active against HL-60 (IC50 = 82.80 ± 13.65 μM) and SK-Mel2 (IC50 = 72.32 ± 1.30 μM) cell lines.