Comparative analysis of hydroxycinnamic acids of Artichoke cultivated in Ukraine and in France

Abstract

Purpose – comparative analysis of hydroxycinnamic acids present in the inflorescences of Artichoke (Cynarae flos) cultivated in Ukraine and in France. Materials and methods. Identification of hydroxycinnamic acids was performed by thin layer chromatography of the ethanol extract of artichoke inflorescence. The research was carried out on TLC plates with a layer of silica gel of 5–40 μm. As the mobile phase 15% acetic acid was used. For the detection of the hydroxycinnamic acid, the chromatogram was handled with 10% solution of potassium hydroxide and diazotized sulfanilic acid, followed by heating the chromatograms in an oven for 3–5 minutes and visual analysis in the daylight. The quantitative content of hydroxycinnamic acids was determined by two methods. Determination was carried out using a spectrophotometric method calculated on the chlorogenic acid and absolutely dry raw material. According to the first method, the absorbance of water extract of the plant material was measured at a wavelength of 327 nm. As for the second procedure, the optical density of alcohol extract of artichoke inflorescence was measured at a wavelength of 525 nm after the reaction of complex formation of hydroxycinnamic acids with solutions of sodium molybdate and sodium nitrite. Results. p-Coumaric, chlorogenic and neochlorogenic acids were identified in both samples of artichoke inflorescence using TLC method by comparison of Rf values, fluorescence under the UV-light before and after the ammonia vapors handle and by color of the spots after handle of chromatograms with ferric (III) chloride solution, 10% potassium hydroxide solution and diazitized sulfanilic acid. The content of hydroxycinnamic acids in artichoke inflorescence harvested in Ukraine and France was determined using the spectrophotometric method. Hydroxycinnamic acid content, determined by the method 1, was 1.64 % and 1.93 %, using method 2–1.66 % and 1.95 %, respectively. Conclusions. The qualitative composition and quantitative content of hydroxycinnamic acids was determined in the artichoke inflorescence harvested in Ukraine and France. The results of the experiment allow to recommend the artichoke inflorescence of both domestic and foreign origin as the source of hydroxycinnamic acids.

Keywords

• Cynara scolymus
• hydroxycinnamic acids
• caffeic acids
• neochlorogenic acid
• ferulic acid
• chromatography
• spectrophotometry