Purification and identification of carvacrol from the root of Stellera chamaejasme and research on its insecticidal activity.

The root powder of Stellera chamaejasme was extracted with petroleum ether. The crude extract obtained was chromatographed repeatedly with silica gel columns. One pure natural product was obtained, which was identified as 5-isopropyl-2-methylphenol (carvacrol), separated for the first time from the root of S. chamaejasme. The results of a laboratory bioassay showed that it had good insecticidal activity against Aphis craccivora and Leucania separata. Its median lethal concentrations (LC(50)) (24 h after treatment) were 16.8 and 12.7 mg L(-1), respectively. This is the first report of the insecticidal activity of carvacrol against A. craccivora and L. separata.