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Isolation, screening, and identification of key components having intense insect repellent activity against Plodia interpunctella from 4 different medicinal plant materials.

BACKGROUND
Global warming and indiscriminate use of pesticides increased the propagation of the stored-product insect pests, leading to the enormous losses in the agriculture and food industries. The most used insect repellents were synthetic derivatives, however, these have an adverse effect on human health as well as on the environment. Therefore, we tried to find materials with insect repellent activity in natural products. This study was carried out to identify the single chemical component having intense insect repellent activity in extracts from the 4 different Oriental medicinal plant materials: (1) A. graveolens L. (dill) seeds; (2) Artemisia capillaris Thunb. (capillary wormwood) leaves; (3) smoked Prunus mume Siebold & Zucc. (mume) fruits; (4) Rhus javanica L. (galls).


RESULTS
As a result of the bioassay-guided fractionation of each extract against the Plodia interpunctella, stored-product insect, the n-Hexane fraction of dill seeds extract was confirmed as the optimal fraction between all of the fractions. In total, 32 chemical components were identified from the n-Hexane fraction of dill seeds by GC-MS analysis, and the two main components were dillapiole (47.51%) and carvone (26.76%). Of the two components, dillapiole was confirmed as the key component playing an essential role in insect repellent activity.


CONCLUSION
Our study suggests that dillapiole has the potential to be used as a natural insect repellent for control of Plodia interpunctella infestation in agricultural and food products during distribution and storage. This article is protected by copyright. All rights reserved.