Growth Inhibition of Colon Cancer and Melanoma Cells by Versiol Derivatives from a Paraconiothyrium Species

Bioassay-guided fractionation of a colon cancer growth inhibitory extract of the fungus Paraconiothyrium sp. led to the isolation of eight new versiol derivatives (1, 38, 10) along with two known compounds. The structures were elucidated by interpretation of combined MS and 2D NMR spectroscopic data. Compounds 8, 9, and 10 showed cell growth inhibition against COLO205 and KM12 cells, and both 8 and 9 displayed selectivity in their inhibition of melanoma cell lines in the NCI 60 one-dose test. In addition, compound 8 and the crude Paraconiothyrium sp. extract showed potent dose-dependent inhibitory effects in the five-dose NCI 60 cell line assay.