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.