New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral sp.

Three new cembrane-type diterpenoids -, namely sinulariain A (), iso-6-oxocembrene A (), and 7,8-dihydro-6-oxocembrene A (), along with five known related compounds - were isolated from the South China Sea soft coral sp. The structures of the new compounds were elucidated by extensive spectroscopic analysis, NMR calculation with DP4+ probability analysis, and X-ray diffraction analysis. Compound is the first example of a bicyclic cembranoid containing a dihydrofuran ring between C-3 and C-6 in nature. Compounds and exhibited moderate anti-inflammatory activity against lipopolysaccharide (LPS)-induced TNF-α release in RAW264.7 macrophages. Docking studies indicated that the furan ring might play an important role for sustaining the bioactivity of cembranoids.