Thiotagetin A, a new cytotoxic thiophene from Tagetes minuta.

Phytochemical investigation of the n-hexane fraction of the methanolic extract of Tagetes minuta L. (Asteraceae) aerial parts afforded a new thiophene derivative: thiotagetin A (3), together with β-sitosterol (1) and stigmasterol (2). The structure of the new thiophene was identified by UV, IR, 1D (1H and 13C), 2D (1H-1H COSY, HSQC and HMBC) NMR and HRESIMS spectral data. Compound 3 displayed cytotoxic activity against KB and MCF7 cancer cell lines with ED50 values of 2.03 and 3.88 μg/mL, respectively, compared to adriamycin (0.26 and 0.07 μg/mL, respectively).