Cembranoids from the Vietnamese soft coral Sarcophyton ehrenbergi

Using various chromatographic separations, two new cembranoids, ehrenbergols F and G (1 and 2), along with three known analogs ehrenbergol D (3), (+)-isosarcophine (4) and sinulariol Z(2) (5) were isolated from the soft coral Sarcophyton ehrenbergi. The structural elucidation was done by extensive analysis of the 1 D and 2 D NMR, HR-ESI-QTOF-MS as well as CD experiments. In addition, compounds 1 (IC50 of 38.38 +/- 2.89 mu M), 3 (IC50 of 37.14 +/- 3.22 mu M) and 4 (IC50 of 45.01 +/- 2.49 mu M) revealed moderate inhibitory activity on LPS-induced NO production in RAW264.7 cells, whereas 2 (IC50 of 73.32 +/- 1.95 mu M) and 5 (IC50 of 64.48 +/- 4.93 mu M) exhibited weak effect.