Synthesis and cytotoxicity of novel isomeric C-seco limonoids.

Attempts to cleave the C-ring in the bioactive limonoids characteristic of the species Azadirachta indica A. Juss using BF(3) x OEt(2) and (C(4)H(9))(4)NBr resulted in novel isomeric C-seco limonoids. Structure related cytotoxic properties of the isomers and the native compounds have been studied using brine shrimp lethality bioassay (BSLB) method and molecular descriptors viz., theoretical and chromatographic hydrophobicity constants, oxidation state and molecular modelling studies. The O-O diad distances reveal the significance of the orientation of the furan ring in enhancing the cytotoxicity of the molecule.