Polyketides with Anti-Inflammatory Activity from Trichoderma koningiopsis , a Rhizosphere Fungus from the Medicinal Plant Polygonum paleaceum .

Twelve new fungal polyketides, koningiopisins I-P ( 1 - 8 ) and trichoketides C-F ( 9 - 12 ), together with six known congeners ( 13 - 18 ), were isolated from Trichoderma koningiopsis , a rhizosphere fungus obtained from the medicinal plant Polygonum paleaceum . Their structures and absolute configurations were established by spectroscopic analysis, single-crystal X-ray diffraction, the modified Mosher's method, chemical derivatization, the octant rule, and 13 C NMR and ECD calculations. Compounds 1 - 5 are tricyclic polyketides possessing an octahydrochromene framework with a 6,8-dioxabicyclo[3.2.1]octane core. Compounds 7 and 8 contain a unique ketone carbonyl group at C-7 and differ from other members of this group of compounds with the ketone carbonyl group at C-1. Compounds 1 , 2 , and 13 showed inhibitory activity on LPS-induced BV-2 cells on NO production with IC 50 values of 14 ± 1, 3.0 ± 0.5, and 8.9 ± 2.7 μM, respectively.