Triterpene acids are common metabolites in the Myrtaceae family, especially in the genus Eugenia. Ursolic acid was found in Eugenia brasiliensis collected in Southeastern Brazil. A previous solvent partition of the ethanol or chloroform extracts of the leavesof E. brasiliensis, followed by rapid high-speed counter-current chromatography (HSCCC) afforded ursolic acid in high purity (> 97%). This compound was also purified apart by conventional column chromatography (yield of 0.22% from the ethanolic extract) and characterized by 13C-NMR, GC-MS and co-injection of its methyl ester with standards in GC-FID. The HSCCC technique, usually applied to triterpene glycosides, was here applied successfully to an aglycone, to which examples are rarely described. The mobile and stationary phase for the HSCCC experiment were derived from the two-phase solvent system composed by n-hexane : ethyl acetate : methanol : water in the proportion of 10:5:2.5:1. The choice of the developing solvent system for optimum HSCCC separation was determined by TLC coupled to densitometric measurements of ursolic acid in both stationary and mobile phase, generated by the upper and lower layer of the system above. Commercial ursolic acid was used as standard.
Eugenia brasiliensis; Myrtaceae; ursolic acid; counter-current chromatography
