CHARACTERIZATION OF ORTHOSIPHON STAMINEUS BENTH EXTRACTS BY REVERSED-PHASE THIN LAYER CHROMATOGRAPHIC METHODS

TLC is a powerful method used for separation of complex mixtures such as plant extracts. Employing different TLC techniques the separations can be improved. This paper presents a study of the Orthosiphon stamineus Benth extracts using isocratic reversed-phase thin layer chromatography (RP-TLC) and reversed-phase automated multiple development technique (RP-AMD). Methanol (SI) and a mixture of methanol-water-methyl acetate (SII) were used as extraction agents. Orthosiphon stamineus Benth. belongs to the Lamiaceae family. Its leaves contain rosmarinic acid, sinesetine and eupatorine as main compounds. After TLC separation the bioactive compounds from plant extracts were identified by comparison of the R-f values and in situ UV-Vis spectra with those of the standards and quantified using the calibration method. The rosmarinic acid was better extracted in the solvent mixture methanol-water-methyl acetate (10:10:80, v/v), while the sinesetine and eupatorine, which are more lipophilic, were better extracted in methanol. The study revealed the AMD technique superiority in comparison with the isocratic one.