GC-based analysis of insecticidal constituents of the flowers of Azadirachta indica A. Juss.

The present article describes the analysis of an n-hexane soluble fraction of fresh flowers of Azadirachta indica A. Juss (Neem), possessing larvicidal activity against Anopheles stephensi Liston, a vector of malarial parasite. Forty-one compounds were identified in non-polar to less-polar fraction as well as in essential oil.

Analysis of insecticidal Azadirachta indica A. Juss. fractions.

As a result of chemical investigation on the ethanolic extract of fresh fruit coatings of Azadirachta indica A. Juss. (neem), twenty-seven compounds were identified in non-polar to less polar fractions which showed pesticidal activity determined by WHO method against Anopheles stephensi Liston.

Tetracyclic triterpenoids from the leaves of Azadirachta indica and their insecticidal activities.

A new tetranortriterpenoid, meliatetraolenone [24,25,26,27-tetranor-apotirucalla-(apoeupha)-6alpha-O-methyl, 7alpha-senecioyl(7-deacetyl)-11alpha,12alpha,21,23-tetrahydroxy-21,23-epoxy-2,14,20(22)-trien-1,16-dione] (1) was isolated from the methanolic extract of fresh leaves of Azadirachta indica along with the known compound odoratone (3) which was hitherto unreported from this source. Their structures have been elucidated by spectral studies including 2D NMR. The insecticidal activities of 1 as well as those of odoratone (3) are reported.