Diterpenes, grayanoid

Figure 6. Grayanoid Diterpenes with insect antifeedant activity.

Three grayanoid diterpenes are the most active constituents from dried flowers of the Chinese insecticidal plant, Rhododendron molle. Rhodojaponin III (49), the major compound, has antifeedant, growth inhibitory, and insecticidal activity against the larvae of Leptinotarsa decemlineata and Spodoptera frugiperda (Klocke et al., 1991). 

El-Naggar, S. F., R. W. Doskotch, T. M. O Dell, and L. Girard, Antifeedant diterpenes for the gypsy moth larvae from Kalmia latifolia Isolation and characterization of 10 grayanoids, J. Nat. Prod., 43, 617-631 (1980). 

Klocke, j. a., M. Hu, S. Chiu, and I. Kubo, Grayanoid diterpene insect antifeedants and insecticides from Rhododendron molle. Phytochemistry, 30, 1797-1800 (1991). 

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