Rapid separation of triterpenoids from Neem seed extracts

Abstract

A dichloromethane extract of the triterpenoids from seeds of the Neem tree (Azadirachta indica) can be fractionated rapidly and with economic use of solvents using the Biotage® flash chromatography system. The fractions can be analysed by thin layer chromatography (TLC), or quantitatively, by supercritical fluid chromatography or high performance liquid chromatography (HPLC), for the determination of 11 tetranortriterpenoids, including the natural insecticide azadirachtin. After a second pass through the Biotage flash column, pure compounds, including azadirachtin and salannin can be obtained directly, although these compounds comprise less than 0.3% of the total mass of the seeds extracted and are present in a complex mixture of similar substances.