Growth Inhibition of Colon Cancer and Melanoma Cells by Versiol Derivatives from a <i>Paraconiothyrium</i> Species

Bioassay-guided fractionation of a colon cancer growth inhibitory extract of the fungus <i>Paraconiothyrium</i> sp. led to the isolation of eight new versiol derivatives (<b>1</b>, <b>3</b>–<b>8</b>, <b>10</b>) along with two known compounds. The structures were elucidated by interpretation of combined MS and 2D NMR spectroscopic data. Compounds <b>8</b>, <b>9</b>, and <b>10</b> showed cell growth inhibition against COLO205 and KM12 cells, and both <b>8</b> and <b>9</b> displayed selectivity in their inhibition of melanoma cell lines in the NCI 60 one-dose test. In addition, compound <b>8</b> and the crude <i>Paraconiothyrium</i> sp. extract showed potent dose-dependent inhibitory effects in the five-dose NCI 60 cell line assay.