New thymol and isothymol derivatives from Eupatorium fortunei and their cytotoxic effects

Four new thymol derivatives (1-4), one new isothymol derivative (5), together with one known analogue (6) were isolated from the overground parts of Eupatorium fortunei. The structures were elucidated by extensive spectroscopic data analysis, including UV, IR, HR-ESIMS, 1D-, and 2D-NMR data. All compounds were evaluated for their cytotoxic effects against four human cancer cell lines using MTT assay. Compounds 1, 2, and 6 showed cytotoxicities with IC₅₀ values 6.24-11.96 μM against MCF-7, HeLa, A549, and Hep G-2 cell lines.