Cytotoxic thiophenes from the root of Echinops grijisii Hance.

A new thiophene, echinothiophenegenol (1), together with seven known thiophenes was isolated from the crude ethanol extract of roots of Echinops grijisii Hance. The structure of 1 was elucidated on the basis of spectroscopic data. Compounds 2 and 5, isolated from the plant for the first time, and compounds 1-7 were tested for their cytotoxicity against two human cancer cell lines, HL60 and K562. The thiophenes showed better activity than the bithiophenes.