Identification of acarcidal compounds in Inula japonica extracts against Tetranychus cinnabarinus

Abstract

In this study, we aimed to identify acaricidal compounds in Inula japonica against Tetranychus cinnabarinus. Here, I. japonica petroleum-ether extracts were found toxic to T. cinnabarinus with a LC50 value of 1.18 mg/ml. Silica gel column chromatography was used to further separate acaricidal components from I. japonica petroleum-ether extracts. Contact toxicity data showed that 17 out of 38 fractions groups had mite mortality rates above 50%, 9 fraction groups above 60 %, and fractions groups G5, G7 and G15 even above 80 % at a concentration of 2 mg/ml. The major vital compounds in the bioactive fraction groups were identified by GC/MS, and four compounds, namely β-Sitosterol (1), Stigmasterol (2), Lupeol (3), and α-Amyrin (4) were determined to have acaricidal activity to Tetranychus cinnabarinus. © 2012 Springer-Verlag GmbH.