HPTLC-densitometry determination of triterpenic acids in Origanum vulgare, Rosmarinus officinalis and Syzygium aromaticum.

Spices play an important role in the chemoprevention and they can be a rich source of biologically active compounds such as triterpenes in the human diet. A method based on high performance thin-layer chromatography combined with densitometry for determination of ursolic and oleanolic acids in some common spices was elaborated. The prechromatographic derivatization with 1% of iodine solution was used to enable simultaneous analysis of these triterpenes. The extracts were separated on HPTLC silica gel 60 F254 plates with use of mobile phase consisting of toluene-petroleum ether-ethyl acetate-acetonitrile 5: 5: 1: 0.3 (v/v/v/v). After drying, the plates were sprayed with 10% (v/v) ethanol solution of sulfuric acid (VI) and heated to 120 degrees C for 3 min. Quantification was performed in fluorescence/reflectance mode at a wavelength of 400 nm using a computer-controlled densitometer Desaga CD 60.