Secondary Metabolites from sp. and Structural Revision of Emericellins A and B.

Seven previously undescribed compounds were isolated from the endophytic fungus sp. KYG-19 (family Xylariaceae), including three gymnomitrane-type sesquiterpenes xylariacinols A, B, and D (, , and ), one bisabolane-type sesquiterpene annulnol F (), one phenol derivative lariacinol G (), and two polyhydroxy compounds hypoxylonols H and I ( and ), together with two known gymnomitrane-type sesquiterpenes emericellin A () and 3-gymnomitren-15-ol (). The assignments of their structures was determined by extensive spectroscopic and spectrometric analysis, acetonide analysis, Mosher's method, and X-ray crystallography. In addition, the structures of emericellins A and B, which were reported to possess an unprecedented tricyclo[4, 4, 2, 1]hendecane scaffold, were revised by comparing their spectroscopic data with those of and . Compounds and exhibited antibacterial activity against with minimum inhibitory concentrations of 4 and 2 μg/mL, respectively.