Evaluation of Hydroxycinnamic Acid Content, Antioxidant Activity of Siberian crab Apple (Malus baccata (L.) Borkh) Leaves

Given the significant interest of researchers in studying a wide range of pharmacological effects characteristic of apple raw materials due to the presence of various groups of biologically active substances (BAS), the object of the study was the Siberian crab apple leaves (Malus baccata (l.) Borkh), growing in the Botanical Garden of Moscow State University. Lomonosov, as well as in gardens and parks of ecologically safe areas of the Moscow region, including from varietal plants “Street Parade” (Archiland plant nursery) harvested during the flowering, fruiting and autumn period of fruit fall (September 2024).

The analysis was performed on a GILSON high-performance liquid chromatograph, model 305 (France), manual injector, model RHEODYNE 7125 USA. A metal column with a size of 4.6 x 250 mm KROMASIL C18 was used as the stationary phase, and a mixture of acetonitrile – water – phosphoric acid concentrated in a ratio of 20:80: 0.05 was used as the mobile phase. The quantitative content of hydroxycinnamic acids in the M. baccata leaves was determined by spectrophotometry in terms of caffeic acid (3,4-dioxycinnamic acid, 3-(3,4-dihydrophenyl)-2-propenic acid).

The authors studied the composition of the polyphenolic fraction, isolated a number of hydroxycinnamic acids and carried out their quantitative assessment. Based on the analysis of data from HPLC analysis of phenolic derivatives, caffeic, gallic, chicory, chlorogenic, neochlorogenic, cinnamic acids, catechin, epicatechin, vicenin, rutin, coumarin, epicatechingallate quercitin, floretin, floridzine, apigenin were determined. The presence of flavonoids floretin, floridzine and vicenin, previously found in extracts from the leaves of forest and domestic apple trees, can be considered as a probable identifier of the genus Malus. Hydroxycoric acids such as caffeic, gallic, chicoric, chlorogenic, neochlorogenic, and cinnamic acids have been identified. The content of hydroxycinnamic acids in terms of caffeic acid, depending on the phase of vegetation, was revealed by spectrophotometric analysis. The authors found that the maximum amount of hydroxycinnamic acids accumulates in the plant during the fruiting phase.

The analysis allows us to determine and identify phenolic derivatives in the fraction in extracts from apple leaves, which will simplify the standardization of raw materials in the preparation of appropriate regulatory documentation