The MeOH extract of the Vietnamese octocoral Dendronephthya mucronata afforded four bicyclic lactones (1-4), including three new compounds namely dendronephthyones A-C (1-3), after subjecting it on various chromatographic separations. The structures of the isolated compounds were established by spectroscopic experiments including 1D, 2D NMR, CD and HR-QTOF-MS. In addition, compounds 1-4 were found to exhibit selective cytotoxicity against the HeLa human cancer cell line with IC50 values of 32.48 ± 2.15, 30.12 ± 1.86, 35.14 ± 1.57 and 14.45 ± 1.34 μM, respectively.
Keywords: Dendronephthya mucronata; Nephtheidae; bicyclic lactone; cytotoxic activity.