HPTLC determination of lupeol in<i>Grewia tiliaefolia</i>

Abstract

Among the complex mixture of biologically active compounds in the bark of Grewia tiliaefolia , a plant used in folklore, lupeol, a constituent of the bark, has been used as an analytical marker indicative of the quality of the plant. A sensitive and reliable quantitative high-performance thin-layer chromatographic method has been developed for the determination of lupeol from Grewia tiliaefolia . Chloroform extracts of bark from five different sources were used for HPTLC on silica gel with benzene-ethyl acetate, 95 + 5, as mobile phase. Under these conditions the RF of lupeol was 0.40. The calibration plot was linear in the range 0.5 to 1.5 μg lupeol and the correlation coefficient, 0.999, was indicative of good linear dependence of peak area on concentration. The mean assay of lupeol was 2.902 ± 0.243 mg g −1 bark. The method enables reliable quantification of lupeol and good resolution and separation of lupeol from other constituents of Grewia tiliaefolia . To ascertain the purity of the peak from the test sample its in-situ reflectance spectrum was compared with that from standard lupeol; clear superimposibility indicated the purity of the peaks. Recovery values from 98.00 to 99.78% showed the reliability and reproducibility of the method were excellent. The HPTLC method proposed for quantitative monitoring of lupeol in Grewia tiliaefolia is rapid, simple, and accurate and can be used for routine quality testing.