Analysis of small samples of limonoids of neem (Azadirachta indica) using solid phase extraction from tissue culture

The limonoids (triterpenoids), including the natural insecticide azadirachtin, from the seeds of the neem tree (Azadirachta indica) can be partially purified and separated into groups for final analysis very quickly by the use of solid phase extraction procedures. The individual compounds can then be accurately quantified in the separated fractions by supercritical fluid chromatography or high pressure liquid chromatography, The method is particularly useful for the small samples available from tissue culture experiments, but is equally applicable to analysis of seed extracts. Two alternative procedures are described, one that gives six fractions and more accurate quantification, and a second shorter, faster procedure for smaller samples that gives two fractions. Both procedures include the quantification of azadirachtin, Copyright (C) 2000 John Wiley & Sons, Ltd.