The vegetable extracts were cleaned up as follows; A 10 mm chromatographic column was filled with 3g activated silica gel and topped up with 2 to 3 g of anhydrous sodium sulphate, and 5 ml of n-hexane was added to the column. The residue in 2 ml n-hexane was transferred onto the column and the extract was rinsed thrice with 2ml hexane. The procedure was repeated for all the samples. The sample was collected in a 2 ml vial, sealed and placed in the refrigerator in the laboratory with temperature below normal room temperature, to prevent evaporation of the
ethyl acetate.