Cytotoxic and anti-bacterial evaluation of two new aromatic A-ring steroids isolated from the Red Sea soft coral Dendronephthya spp.

Abstract

A successful column chromatography of a CHCl3/MeOH crude extract of Dendronephthya spp. soft coral led to the isolation of two new aromatic A-ring steroids (1–2), together with three known compounds (3–5). Both 1 and 2 are 19-norsteroids. The chemical structures were elucidated based on extensive 1D, 2D NMR, and EIMS analyses. In cytotoxic bioassays, compounds 1–5 were tested against three cancer cell lines: MCF-7, NCI-1299, and HepG2, with IC50 in the ranges of 22.1–85.4, 26.9–88.7, and 25.9–93.7 μM, respectively. Compounds 1, 2, and 5 showed moderate degrees of inhibition against Escherichia coli and Pseudomonas sp. at 100 and 150 µg/mL, while exhibiting weak inhibition against Bacillus cereus and Staphylococcus aureus at 150 µg/mL.