Xylarinic Acids A and B, New Antifungal Polypropionates from the Fruiting Body of Xylaria polymorpha

Two new polypropionates designated as xylarinic acids A and B were isolated from the fruiting body of Xylaria polymorpha . Their structures were established as 4,6,8-trimethyl-2,4-decadienoic acid and 2,4,6-trimethyl-2-octenoic acid, respectively, on the basis of extensive spectroscopic analysis. Both compounds displayed significant antifungal activity against plant pathogenic fungi Pythium ultinum , Magnaporthe grisea , Aspergillus niger , Alternaria panax , and Fusarium oxysporium , whereas they did not show antibacterial and cytotoxic effect.