DEVELOPMENT OF A DENSITOMETRIC HIGH-PERFORMANCE THIN-LAYER CHROMATOGRAPHIC METHOD FOR THE QUANTITATIVE ANALYSIS OF URSOLIC ACID IN THE LEAVES OF SPECIES OF GENUS TECOMA AND TABEBUIA OF BIGNONIACEAE FAMILY

摘要

Objective: A simple and sensitive high-performance thin–layer chromatographic (HPTLC) method was developed for the quantification of ursolic acid in the leaves of three species of genus Tecoma ( Tecoma gaudichaudi DC, Tecoma capensis (Thunb.) Lindl, Tecoma stans (L.) Juss. ex Kunth) and genus Tabebuia ( Tabebuia rosea Bertol) belong to family Bignoniaceae. Methods: Chromatography was performed on Silica gel 60 F254 precoated HPTLC Plates with optimised mobile phase pet ether: ethyl acetate: formic acid (7:3:0.5, v/v/v). The plate was derivatized with p-anisaldehyde reagent and scanned at 540 nm. The developed method was found to give a compact spot for ursolic acid at R f value 0.43±0.01. The method was validated using International Council for Harmonization (ICH) guidelines, including linearity, precision, accuracy, and robustness. Results: Ursolic acid was found to be present in four species, i.e., Tecoma gaudichaudi DC (1.48%w/w), Tecoma capensis (Thunb.) Lindl. (0.79%w/w), Tecoma stans (L.) Juss. Ex Kunth (1.11%w/w), Tabebuia rosea (Bertol.) (1.13%w/w). A good linearity relationship was found to be (200-1400ng band?1) with a correlation coefficient (r 2 ) value of 0.9946 with ursolic acid. Limit of detection and limit of quantification was considered to be 40.66, 123.21 ng per band respectively. The developed method was found to be accurate and precise with 1.32%, 1.19% (%RSD) for interday and intraday precision. The accuracy of the method was performed by recovery studies at three different concentration levels, and the average percentage recovery was found to be 98.05% for ursolic acid. Conclusion : The proposed method for the quantitation of ursolic acid was found to be reproducible and simple.