Cytotoxic antifeedant from Dionaea muscipula ellis: A defensive mechanism of carnivorous plants against predators

We revealed that Dionaea muscipula Ellis accumulates a great amount of cytotoxic naphthoquinone derivatives, of which the main component is plumbagin (1). It was also revealed that 1 showed strong antifeedant activity against Spodoptera litura. These results strongly suggest that 1 in D. muscipula operates as an antifeedant which prevents them from being consumed by predators. The accumulation of a great amount of 1 would be an important strategy of carnivorous plants for their survival. Also, we discuss the structure-activity relationship of the cytotoxicity of naphthoquinones using isolated naphthoquinones and their derivatives.