Guaiane sesquiterpenes and isopimarane diterpenes from an endophytic fungus Xylaria sp.

Nine guaiane sesquiterpenes and three isopimarane diterpenes were isolated from the endophytic fungi Xylaria sp. YM 311647. The absolute configurations of 1 and 2 were confirmed by X-ray crystallography. All compounds were tested for their antifungal activities, with one (compound 12) having the most potent activity.