Contribution to the TLC separation of ursolic and oleanolic acid mixture

The aim of the study was to develop a rapid, simple, effective and reproducible TLC method for separation of a naturally occurring mixture of ursolic and oleanolic acids. Because of the similarity of chemical structures, in situ derivatisation by iodine was necessary to separate these triterpenic acids. Separation was achieved on silica gel plates. After derivatisation, a chromatographic plate was developed with the mobile phase consisting of light petrol, ethyl acetate and acetone (8.2:1.8:0.1, v/v/v) following visualisation by spraying with sulphuric acid in diethylether (25%, v/v) and heating to 120°C for 5 min. The method used enabled chromatographical differentiation of ursolic and oleanolic acid mixtures in all tested mutual ratios.