Cladosporitides A–C, three polyketides from an endophytic fungi Cladosporium tenuissimum

Three new polyketides, named cladosporitides A–C (1–3), were isolated from an endophytic fungi Cladosporium tenuissimum derived from the stem of Berberis heteropoda. Their structures were determined by extensive spectroscopic analysis including HRMS, 1D and 2D NMR data. Compound 1 possesses an unusual octahydro-2H-2,5-epoxychromene tricyclic structure moiety. An anti-inflammatory assay indicated that compounds 1–3 showed moderate inhibitory activities against LPS-induced NO production in RAW 264.7 cells with IC50 values ranging from 22.32 to 33.97 μM.