Three new tetranortriterpenoids from neem seed oil

Abstract

Three new tetranortriterpenoids, 1alpha,2alpha epoxy 17beta hydroxyazadiradione (1), 1alpha,2alpha epoxymmolicinol (2), and 7 deacetylnimolicinol (3), have been isolated from a methanol extract of neem oil (Azadirachta indica, seed oil) along with the known compounds epoxyazadiradione, 17beta hydroxyazadiradione, gedunin, nimbin, and nimolicinol (4) Spectral studies and chemical transformations were used to establish the structure of compounds 1-3 The characterization of the epoxides 1 and 2 in neem oil is of biogenetic significance, as they may be considered as intermediates between A ring enones and 1,3 diols among the A indica tetranortriterpenoids.