HPTLC Quantification and Antimicrobial Activity of Ursolic Acid from Diospyros melanoxylon

Abstract

An important bioactive molecule, ursolic acid was isolated from the leaves of Diospyros melanoxylon and characterized with help of physical and spectroscopic data viz. m. p, IR, H-1, and C-13 NMR. A high-performance thin-layer chromatography method has also been developed and validated for its quantification in D. melanoxylon leaves. The high-performance thin-layer chromatography analysis was performed on high performance thin-layer chromatography plates using chloroform-methanol (9.5:0.5, v/v) as mobile phase. The compound was quantified at 540 nm after derivatzation with sulphuric acid reagent. The sensitivity of the method with respect to limit of detection and limit of quantification were found to be 20 and 40 ng per spot. The response was obtained as a linear function of peak area and concentration in the range of 50 to 450 ng per spot with correlation coefficient of r(2) = 0.9998. The method showed excellent accuracy greater than 97.54% with acceptable precession and was successfully validated according to International Conference of Harmonization protocols. Antimicrobial screenings of ursolic acid revealed potent activity against two Gram-positive bacteria viz. Staphylococcus aureus and Enterococcus faecalis and three fungal starins viz. Aspergillus niger, Candida tropicalis, and Candida albicans.