Studying the acids and amino acid composition of horse chestnut flowers

Abstract

Introduction. Currently, there is an increasing trend towards assessing the full spectrum of chemical compounds in plant materials. One of the first steps in the formation of secondary metabolites of complex structure, participating in biochemical processes in the plant body, which have their own effect on the human and animal body, are organic acids (OA) and amino acids (AA). However, due attention is not always given to these compounds when studying the component composition of plant raw materials.Aim. The purpose of the work was to study the profile and quantitative assessment of the content of organic acids and amino acids of Aesculus hippocastanum L. flowers.Materials and methods. The object of the study were horse chestnut flowers, collected during flowering in the Voronezh region in 2021 and dried by air-shade method. Quantitative assessment of the amount of TC in terms of malic acid and ascorbic acid was carried out titrimetrically according to the methods presented in the State Pharmacopoeia of the Russian Federation, XIV edition. The composition of the OA and AA profiles of horse chestnut flowers was determined using the capillary electrophoresis method ("Kapel®-105/105M", Group of Companies "Lumex", Russia).Results and discussion. The method of capillary electrophoresis revealed the presence of 12 compounds of the OA group in a total amount of 4.7 % (in terms of absolutely dry raw materials). The rationality of recalculating the content of the sum of OA to the major component – citric acid, which amounted to 1.65 ± 0.04 %, was shown. The content of ascorbic acid was low (0.033 ± 0.007) %. Using the TLC method, the presence of 5 zones of compounds belonging to the AA class was established in the aqueous extract of horse chestnut flowers. The quantitative content of the sum of free AA in terms of glutamine, determined by the spectrophotometric method, was 2.25 ± 0.07 % (n = 5). The presence of 17 AA was determined by capillary electrophoresis, which amounted to 7.13 %. Glutamic acid is present in the greatest quantity in horse chestnut flowers (1.19 %). Essential amino acids amounted to 2.27 %; leucine was present in the predominant amount (0.58 %).Conclusion. A study was carried out of the qualitative composition and quantitative content of organic acids and amino acids of horse chestnut flowers. The composition of the profile and the quantitative content of organic acids and amino acids have been established. It was revealed that citric acid prevails in the total organic acids; glutamic, aspartic acid, arginine and proline are found in greater quantities in the total amino acids.

Keywords

• horse chestnut
• flowers
• organic acids
• amino acids
• capillary electrophoresis