An improved thin-layer chromatographic separation and quantitative estimation of ursolic acid in different plant parts of various
Ocimum species have been developed and validated. Excellent separation of the components was achieved on high-performance precoated
TLC plates by using optimized ternary mobile phase consisting of toluene : acetone : formic acid (7.8 : 2.2 : 0.15, v/v/v). Quantification and
densitometric determination were performed after derivatization of the plate with methanol-sulphuric acid reagent in reflection/absorption
mode at 540 nm. The limit of detection and limit of quantification were found to be 20 and 35 ng/spot, respectively. The response of ursolic
acid was linear over the range of 40 to 440 ng/spot with a correlation coefficient of r
2
=0.9995, indicating good relationship between peak
area and concentration. Recovery values from 98.36 to 100.06% showed excellent accuracy of the method. The method was validated
according to ICH protocol for precision, repeatability and accuracy. Ursolic acid was efficiently separated from the other components by
the proposed method which was very simple, rapid, precise, sensitive and accurate for the quantification of ursolic acid in different plant
parts of Ocimum species. The maximum ursolic acid content was found in the stems.