High-performance thin-layer chromatographic analysis for the simultaneous quantification of four phenolics in flowers and flower buds ofBauhinia purpureaL.,Bauhinia variegataL., andBauhinia acuminataL.

Abstract

A high-performance thin-layer chromatographic (HPTLC) method for the simultaneous quantitative determination of caffeic acid, vanillic acid, syringic acid and kaempferol in flowers and buds of three different Bauhinia species was developed for the first time in the case of these species. Methanol was found to be the best for the highest possible recovery of target analytes. For achieving good separation, a mobile phase of toluene—ethyl acetate—formic acid (5:4:1, v/v) was used. The densitometric determination was carried out at 350 nm in reflection—absorption mode. The calibration curves were linear in the range of 100–700 ng per spot for caffeic acid, vanillic acid, syringic acid, and kaempferol. The methanolic fractions of Bauhinia variegata L. flowers (BVFM) showed the highest amount of caffeic acid (0.08%), B. variegata L. buds (BVBM) and Bauhinia purpurea L. flowers (BPFM) showed the highest amount of kaempferol (1.53%), Bauhinia acuminata L. flowers showed the highest amount of vanillic acid (0.40%)...