Phytotoxic activity and conformational analysis of thymol analogs from Hofmeisteria schaffneri

Thymol analogs, 3-5, along with seven known compounds (1, 2 and 6-10), were isolated from the aerial parts of Hofmeisteria schaffneri (Asteraceae). Their conformational behavior was studied by molecular modeling using DFT calculations; 1-4 and 6-10 inhibited radicle growth of seedlings of Amaranthus hypochondriacus and Echinochloa crus-galli with IC50's ⩽ 10−4 M.