After evaporation of the solvents under reduced
pressure, the crude extracts were used for the insecticidal
activity to P. xylostella third instar larvae. Ten g portions
of the crude extract which exhibited highest mortality of
larvae was first fractionated on a silica gel (70-230 mesh)
column chromatography and eluted with 20% step gradient
of hexane in ethyl acetate and then with methanol. The
most active fraction was further isolated by repeated column
chromatography and purified by preparative TLC (silicagel
60 F254, Merck) using 20% ethyl acetate in methanol as the
developing solution. Identification of the most active
compound was carried out by spectroscopic techniques
like HR-MS, IR and 1NMR.