Insecticidal, antifeedant and antifungal activities of two glucosides isolated from the seeds of Simmondsia chinensis

Insecticidal, antifeedant and antifungal activities of two glucosides isolated from the seeds of jojoba plant, Simmondsia chinensis (Link) Schneider, were tested. Bioassay-driven fractionations of the chloroform extract of the plant seeds over silica gel columns followed by recrystallization afforded two glucosides, simmondsin and simmondsin 2′-ferulate. The structure of these glucosides was confirmed by physico-chemical properties and spectroscopic analyses. In topical application assay, simmondsin and simmondsin 2′-ferulate showed a strong insecticidal activity against the third instar larvae of Spodoptera littoralis Boisduval (Lepidoptera: Noctuidae) with LD50 values of 1.49 and 2.58 μg/larva, respectively. Both compounds showed antifeedant activity against S. littoralis in a concentration-dependent manner. In addition, the isolated compounds showed moderate to high antifungal activity against four plant pathogenic fungi. This is the first study on the insecticidal, antifeedant and antifungal activities of these glucosides.