Cytosporinols A-C, new caryophyllene sesquiterpenoids from Cytospora sp

Three new caryophyllene sesquiterpenoids, cytosporinols A-C (1-3), have been isolated from solid cultures of Cytospora sp. The structures of 1-3 were elucidated primarily by NMR spectroscopy, and 3 was further confirmed by X-ray crystallography. The absolute configurations of the C-11 secondary alcohol in 1 and the 6,8-diol moiety in 3 were deduced using the modified Mosher and Snatzke's method, respectively. Compounds 2 and 3 showed moderate cytotoxicity against HeLa cells.