Mililatensols A-C, New Records of Sarsolenane and Capnosane Diterpenes from Soft Coral Sarcophyton mililatensis .

Three unusual diterpenes with rare sarsolenane and capnosane skeletons, namely mililatensols A-C ( 1 - 3 ), were isolated from the South China Sea soft coral Sarcophyton mililatensis , leading to the first record of sarsolenane and capnosane diterpenes from the title animal. The structures of compounds 1 - 3 were established by extensive spectroscopic analysis and comparison with the literature data. Moreover, the absolute configuration of 2 was determined by TDDFT ECD calculations. In an in vitro bioassay, none of the isolated compounds showed obvious anti-inflammatory activity on LPS-induced TNF- α release in RAW264.7 macrophages. In the preliminary virtual screening of inhibitory potential against SARS-CoV-2 by molecular docking, the results showed these three diterpenes were potential SARS-CoV-2 M pro inhibitors.