A preliminary study on activity mechanism and identification of an extract of Pharbitis purpurea seeds against Tetranychus cinnabarinus

Abstract

The isolation fraction 8 of petroleum ether extract of Pharbitis purpurea (P. purpurea) seeds was identified and its action mechanism against Tetranychus cinnabarinus (T. cinnabarinus) was initially investigated. Thin-layer chromatography (TLC) was used to measure purity of the isolation fraction 8. Ultraviolet (UV) and infra-red (IR) spectrum, nuclear magnetic resonance (NMR), gas chromatography and mass spectrum (GC-MS) were used to identify the main component of the isolation fraction 8. The influence of several kinds of enzyme activity such as glutathione-S-transferase (GSTs), acetylcholine esterase (AChE), mono-amine oxidase (MAO) and ATPase in body of T. cinnabarinus was tested with the biochemical method. Results showed that the isolation fraction 8 was the methyl linoleate. The methyl linoleate could activate GSTs in T. cinnabarinus. The isolation fraction 8 had strong toxic effect on T. cinnabarinus because it could inhibit in various degrees AChE, MAO and ATPase related to nervous system, which might lead to blocking neurotransmission and the death of mites. So, P. purpurea seeds have better development prospects that the methyl linoleate is regarded as new pesticide. © 2012 Springer-Verlag GmbH.