Triterpene derivatives of azadirachtin having insect antifeedant and growth inhibitory activity and a process for extracting such compounds from the neem plant

摘要

The invention discloses novel triterpene derivatives of azadirachtin of the formulae 2 to 11 of the drawings and a process for isolating new triterpene derivatives of azadirachtin from the various parts of the neem plant(Azadirachta indica A-Juss), which process comprises grinding the parts of the neem plant to get a powder, extracting the powder with a binary immiscible solvent consisting of one polar and another non-polar solvent in a ratio of 1:2 to obtain an extract, filtering the extract to get a filtrate having two layers, one layer containing lipids and the other layer containing the new triterpene derivatives of azadirachtin and water soluble constituents including sugars, separating the layers by known methods, concentrating the layer containing the new triterpenes of the formulae 2-11 including derivatives of azadirachtin and water soluble salts, treating the resultant concentrate with a polar solvent and if necessary, warm the concentrate having the solvent, and filtering/decanting the resultant solution to produce a filtrate containing the mixture of the new triterpene derivatives of azadirachtin. The lipid layer is concentrated in any known manner, the lipid concentrate is treated with a polar solvent, chilled to a temperature of 0 DEG to -10 DEG C. and filtered to produce a filtrate containing lipids. The new triterpene derivatives of azadirachtin are useful in suppressing the insect pest population below the economic threshold level by their antifeedant and growth inhibitory activities.