COX-2 and iNOS inhibitory epimeric meroterpenoids from Ganoderma cochlear and structure revision of cochlearol Q

Four novel epimeric meroterpenoids, ganadone A ( 1 ), 3′,10′-di- epi -ganadone A ( 2 ), 10′- epi -ganadone A ( 3 ), and 3′- epi -ganadone A ( 4 ) as well as another pairs of epimers, ganadone B ( 5 ) and 10′- epi -ganadone B ( 6 ), with a same basic skeleton compound ganadone C ( 7 ), together with two lactonized meroterpenoids, ganadones D and E ( 8 and 9 ) were isolated from the fruiting bodies of Ganoderma cochlear. Compounds 1 – 7 were constructed with fascinating adjacent 6′,7′-bifuran ring system. Fortunately, we have revised our previously reported structure cochlearol Q, which was proposed pyrano[6′,7′- b ]pyran ring system into 6′,7′-bifuran motif. All the isolates were characterized by analysis of HRESIMS, NMR spectroscopy and 1 was supported by X-ray crystallography analysis. The absolute stereochemistry of 1 – 9 were assigned by quantum chemical calculations. Biological evaluation of 1 – 9 showed that 5, 6, and 9 have significant anti-inflammatory potentials.