Paraconulones A-G: Eremophilane Sesquiterpenoids from the Marine-Derived Fungus Paraconiothyrium sporulosum DL-16.

Seven new eremophilane sesquiterpenoids, paraconulones A-G ( 1 - 7 ), along with three previously reported analogues, periconianone D ( 8 ), microsphaeropsisin ( 9 ), and 4- epi -microsphaeropsisin ( 10 ), were obtained from an EtOAc extract of the marine-derived fungus Paraconiothyrium sporulosum DL-16. The structures of these compounds were elucidated by extensive spectroscopic and spectrometric analyses, single-crystal X-ray diffraction, and computational studies. Compounds 1 , 2 , and 4 are the first examples of dimeric eremophilane sesquiterpenoids coupled through a C-C bond identified from microorganisms. Compounds 2 - 5 , 7 , and 10 showed inhibitory effects on lipopolysaccharide-induced NO production in BV2 cells, which were comparable to the positive control curcumin.