Two new meroterpenoids and two new monoterpenoids from the deep sea-derived fungus Penicillium sp. YPGA11.

Twelve terpenoids, including two new 3,5-dimethylorsellinic acid-based meroterpenoids (1 and 2) and two new monoterpenoids (11 and 12), were obtained from the deep-sea fungus Penicillium sp. YPGA11. Their structures were determined by extensive analyses of spectroscopic data, and the absolute configurations of 1 and 2 were determined by comparisons of experimental and calculated ECD spectra. Compounds 1 and 2, bearing a 23-aldehyde or 23-carboxylic acid group, were rarely found in compounds with similar carbon skeleton. All compounds but 11 were evaluated for inhibitory effects towards nitric oxide production induced by lipopolysaccharide in RAW 264.7 macrophage cells. Compound 9 exhibited significant inhibitory effects with an IC50 value of 7.58 μM, being comparable to the positive control, quercetin (10.97 μM).