Terpenoids from Penicillium chrysogenum MT-40, an endophytic fungus isolated from Huperzia serrata

Abstract

Two novel 3,5-dimethylorsellinic acid derived meroterpenoids, peniciterpenolides A (1) and B (2) individually containing a 2-oxaspiro[4,5]deca-6,8-diene-1,4-dione and a 6-oxabicyclic[3,2,1]oct-3-en-7-one motif, one new spongian-type diterpene, peniciterpenolide C (3), and one new drimane-type sesquiterpene, peniciterpenolide D (4), together with the known meroterpenoid atlantinone B (5) were isolated from Penicillium chrysogenum MT-40, an endophytic fungus identified from Huperzia serrata. All the five compounds additionally contain a unique 2-oxabicyclo[2.2.2]octan-3-one moiety formed by the annulation of the C-3 hydroxyl and the oxidized methyl on C-10. The structures were established by the analysis of their spectroscopic data, single-crystal X-ray diffraction, and quantum chemical calculations of electronic circular dichroism spectra. Compounds 1–5 showed inhibition of nitric oxide production in lipopolysaccharide-activated RAW 264.7 macrophage cells with IC₅₀ values in the range of 20.6–46.9 μM.