Anti-neuroinflammatory naphthol dimers from the marine-derived fungus Penicillium sp. HQ1-23.

Five undescribed naphthol dimers, penibinaphthols A-E (1-5), and two known analogues (6 and 7), were isolated from the marine-derived fungus Penicillium sp. HQ1-23. Their structures were elucidated based on spectroscopic data analysis, and the absolute configurations were determined by X-ray crystallographic data and ECD spectroscopic analysis. Compound 3, with a ketone carbonyl group at C-1', potently inhibited LPS-induced NO production in BV-2 microglial cells (IC50 = 6.86 ± 0.10 μM), surpassing that of the positive control minocycline (IC50 = 23.57 ± 0.92 μM). Moreover, compound 3 decreased LPS-induced iNOS and COX-2 expression and reduced LPS-stimulated levels of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6.