High-Performance Thin-Layer Chromatography Analysis for Simultaneous Quantifications of Phenolic Biomarkers in Oxalis corniculata L. Methanolic Fraction

Oxalis corniculata is an important medicinal plant, but chromatographic analysis for the simultaneous quantification of different phenolic compounds has not been performed till date in this plant species. A high-performance thin-layer chromatography (HPTLC) method for the simultaneous quantitative determination of caffeic acid, vanillic acid, and syringic acid in O. corniculata L. methanolic fraction was developed for the first time. In HPTLC, for achieving good separation, the mobile phase of toluene—ethyl acetate—formic acid (7:3:1, v/v) was used. The densitometric determination was carried out at 300 nm in reflection/absorption mode. The calibration curves were linear in the range of 100–700 ng per spot for caffeic acid, vanillic acid, and syringic acid. HPTLC analysis has indicated the presence of optimum amount of caffeic acid (0.025 ± 0.0002), vanillic acid (0.018 ± 0.0005), and syringic acid (0.04 ± 0.0006) in the methanolic fractions. The optimized method was successfully applied for the analysis of three major phenolics in O. corniculata L. The proposed method is simple, precise, specific, and accurate. The quantification of these phenolic compounds has not yet been reported in this species which may be utilized for the proper standardization of the drug.