Antifeedant activities of methanol extracts of four Zanthoxylum species and benzophenanthridines from stem bark of Zanthoxylum schinifolium against Tribolium castaneum

Antifeedant activities of the methanol extracts from Zanthoxylum bungeanum, Zanthoxylum schinifolium, Zanthoxylum armatum and Zanthoxylum dissitum were assessed on Tribolium castaneum adults. It was found that the methanol extract of stem bark of Z. schinifolium had the highest antifeedant activity at 41.12% (antifeedant index). Based on bioactivity-guided fractionation, six benzophenanthridines norchelerythrine (1), decarine (2), 8-hydroxy-9-methoxy-2,3-(methylenedioxy) benzophenanthridine (3), 6-hydroxydihydrochelerythrine (4), 6-methoxy-7-hydroxydihydrochelerythrine (5) and oxychelerythrine (6) were isolated from the stem barks of Z. schinifolium. And their antifeeding activities were also evaluated against T. castaneum. All of them exhibited strong antifeeding activity in a concentration-dependant manner with EC50 of 62.67, 66.97, 151.39, 96.72, 141.61 and 192.32 ppm, respectively. The six bioactive compounds from the stem bark of Z. schinifolium might be used as antifeedants against T. castaneum.