TLC separation of oleanolic and ursolic acids

Objectives:Create an in-situ pretreatment TLC method to separate oleanolic acid and ursolic acid in Chinese material medicas collected in ChP 2005,which use oleanolic acid or ursolic acid as an indicator to test.Method:The samples were treated directly on the chromatographic plate by 1% iodine solution in methylene dichloride and developed with the mobile phase consisting of cyclohexane-methylene dichloride-ethyl acetate-glacial acetic acid (20∶5∶8∶0.1).The plates were sprayed with 10% ethanol solution of sulfuric acid and heated to 105 ℃ for 5 min.Results:Oleanolic acid and ursolic acid were detected in the Chinese material medicas that contain them.The Rf of Oleanolic acid and ursolic acid were 0.54 and 0.38,and they were effectively separated.Conclusion:The results were found to be satisfactory.The method can be used to identify oleanolic acid and ursolic acid in Chinese material medicas simultaneously.