Paecilins F-P, new dimeric chromanones isolated from the endophytic fungus Xylaria curta E10, and structural revision of paecilin A.

A total of eleven new dimeric chromanones, paecilins F-P (-), were isolated from the endophytic fungus E10, along with four known analogs (, -). Their structures and absolute configurations were determined by extensive experimental spectroscopic methods, single-crystal X-ray diffraction, and equivalent circulating density (ECD) calculations. In addition, the structure of paecilin A, which was reported to be a symmetric C8-C8' dimeric pattern, was revised by analysis of the nuclear magnetic resonance (NMR) data, and single-crystal X-ray diffraction. Compound showed antifungal activity against the human pathogenic fungus with a minimum inhibitory concentration of 16 μg/mL, and Compounds and showed antibacterial activity against the gram-negative bacterium with the same minimum inhibitory concentration of 16 μg/mL.