Qualitative evaluation of phenolic compounds and free amino acids in Cirsium vulgare plant raw materials

Abstract

Cirsium vulgare (Savi) Ten. is also known as a bull thistle. It is a species of the Asteraceae, genus Cirsium. This plant is known as biennial native in most of Europe, Western Asia, Northwestern Africa [1]. Studies show that the main active compounds in Cirsium genus plants are flavonoids. It is known that Cirsium vulgare contains secondary metabolites such as sterols and triterpenes, aliphatic aldehydes, phenolic acids [2]. Also, it is suspected that this plant accumulates amino acids like other plants of this genus. Due to this, our main research aim was to identify phenolic compounds and amino acids in Cirsium vulgare plant leaves, roots, flowers raw materials. For these plant parts qualitative evaluation HPLC-PDA (for phenolic compounds) and GC-MS (amino acids) methods were used. Results showed that main phenolic compounds accumulated in Cirsium vulgare raw materials water/ethanol extracts were chlorogenic acid, neochlorogen, p-cumaric acid, hyperoside, isoquercitrine, apigenin, apigenin-7-O-glucoside and luteolin. Amino acids accumulated in plant were L-Alanine, Glycine, L-Valine, L-Leucine, L-Isoleucine, L-Proline, L-Serine, L-Threonine, L-Phenylalanine, L-Aspartic acid, L-Glutamic acid, L-Lysine and L-Tyrosine. A relation between detection of active compounds and the phenological stage and/or part of the plant raw materials were found. The greatest variety of amino acids and phenolic compounds was found during the mass flowering of plants, in the flowers and leaves, respectively.