Santalane-type sesquiterpenoids and isobenzofuranones from cultures of Paraconiothyrium sporulosum YK-03

摘要

Three undescribed santalane-type sesquiterpenoids (parasantalenoic acids A-C) and two undescribed epimeric isobenzofuranones (paraphthalides A and B) were isolated from cultures of the marine mud-associated fungus Paraconiothyrium sporulosum YK-03. Their structures were elucidated by analysis of the extensive spectroscopic and crystal X-ray diffraction data, combined with ECD calculations and comparison. Santalane-type sesqui-terpenoids have been firstly found in the Paraconiothyrium species. Parasantalenoic acids A-C represent three rare polyhydroxylated santalane-type sesquiterpenoid carboxylic acids, and parasantalenoic acid A represents the first example of 2-chlorinated santalane-type sesquiterpenoid. A plausible biosynthetic pathway for para-santalenoic acids A-C was proposed. Additionally, the anti-neuroinflammatory activities of parasantalenoic acids A-C were investigated by evaluating their inhibitory effects on nitric oxide (NO) production in lipo-polysaccharide (LPS)-stimulated BV-2 microglia cells. Among them, parasantalenoic acid C showed significant anti-neuroinflammatory activity with an inhibition of 86.45 +/- 2.45% at 10 mu M.

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