Lobophytones O–T, New Biscembranoids and Cembranoid from Soft Coral Lobophytum pauciflorum

Chemical examination of a Chinese soft coral Lobophytum pauciflorum resulted in the isolation of five new biscembranoids named lobophytones O-S (1-5) and a new "monomeric" cembrane lobophytone T (6). The structures of the new compounds were elucidated by interpretation of 1D and 2D NMR (COSY, HSQC, HMBC, and NOESY) spectroscopic data in association with MS and IR data. Lobophytone Q showed significant inhibition against lipopolysaccharide (LPS)-induced nitric oxide (NO) release in mouse peritoneal macrophages, while lobophytones Q and T showed inhibitory activities against the bacteria S. aureus and S. pneumoniae.