The active fractions
were subjected to thin layer chromatography on precoated silica gel
60 plates DCM: MeOH (95:5) as mobile phase.
The chromatograms were sprayed with spraying reagent (0.5% p-anisaldehyde
254 in MeOH: acetic acid: conc. H2SO
(17:2:1 v/v/v)) followed by incubation at 110°C for 3 min and visualized with iodine vapour.