Study of the composition of fatty and amino acids in the common pear leaves of lisova krasunya variety

Abstract

Introduction. One of the most common groups of biologically active substances formed in plants is amino acids, which are found in plant proteins. They are known to be necessary for the synthesis and metabolism of specific tissue proteins, nucleic acids, bile acids, antibodies, complex carbohydrates, enzymes, fats, hormones, antibiotics, and other amino acids, and for the normal functioning of organs and systems of the human body. In medicine, they are widely used for parenteral nutrition (especially during resuscitation), treatment of diseases of the digestive system, anemia, burns, stomach ulcers, neuropsychiatric and epileptic seizures, for pharmacotherapeutic correction of disorders of the hepatobiliary system, and cancer. Medicines containing amino acids are used for premature aging, congenital and acquired metabolic disorders, the negative effects of ionizing radiation on the body, and acute and chronic poisoning with various substances. They have a positive effect on human cardiovascular and brain activity, promote the restoration of liver and kidney function, improve absorption, prolong the therapeutic effect, and potentiate the action of the main biologically active compounds of plant origin. Plants are the largest source of amino acids (almost 30%), which are found in a free or bound state. Therefore, the use of amino acids in the prevention and treatment of many diseases is becoming increasingly important in many countries, and research in this area is revealing new functions of amino acids and their specific effects on the human body. Essential polyunsaturated fatty acids, in particular ω-6 and ω-3, are no less important for human health. They affect metabolism and nervous system function, participate in fat metabolism, help lower cholesterol levels, prevent the development of atherosclerosis, lower blood pressure, improve blood circulation, reduce the risk of anemia, and prevent inflammation. Moreover, these compounds improve cellular and tissue trophism, stimulate the immune system, serve as precursors of prostaglandins, and positively affect the growth and normal development of the child's body. It is known that omega-3 polyunsaturated fatty acids increase the fluidity of cell membranes, increase the number of receptors and the affinity of insulin for them, and increase the number of glucose transporters, which may represent a promising direction in the treatment of diabetes mellitus. Therefore, the search for promising plant sources of polyunsaturated fatty acids and amino acids is a relevant direction in pharmaceutical science, aimed at developing effective domestic medicines and dietary supplements based on them. The aim of the study was to investigate the qualitative composition and quantitative content of amino and fatty acids in the leaves of the common pear variety Lisova Krasunya, which is widely cultivated in Ukraine. Materials and methods. We selected leaves of the common pear variety Lisova Krasunya, harvested in June 2025 in the Kharkiv region, as the object of our study. The fatty acid composition was studied using a gas chromatograph (Agilent Technologies 7890B) with a mass spectrometric detector (5977 B). The amino acid composition was studied using ion-exchange liquid column chromatography on an AAA T-339M automatic amino acid analyzer manufactured by Microtechn (Czech Republic) and equipped with a recording photocell. Results and discussion. Seven fatty acids were found in the leaves of the common pear variety Lisova Krasunya: four saturated and three unsaturated. Among the identified saturated acids, a significant content was found for palmitic acid – 8.76 ± 0.23%. The predominant unsaturated fatty acids were α-linolenic (46.51 ± 0.42%) and linoleic (42.38 ± 0.37%). The lowest content among saturated acids was stearic acid (0.19 ± 0.05%), and among unsaturated acids, palmitoleic acid (0.23 ± 0.06%). It should be noted that unsaturated fatty acids significantly prevailed in the total content of the leaves of the common pear variety Lisova Krasunya – 89.12%. Sixteen amino acids were found in the leaves of the common pear variety Lisova Krasunya: 7 essential, 5 conditionally essential, and 4 replaceable. The raw material studied contained significant amounts of glutamic and aspartic acids, leucine, and slightly lower levels of lysine, isoleucine, phenylalanine, arginine, and valine. Cysteine and tyrosine were identified in minor amounts. It should be noted that, in terms of total content in the leaves of the common pear variety Lisova Krasunya, replaceable amino acids slightly prevailed – 56.49%. Among the essential amino acids, which are of greatest interest to the human body, leucine (4.98 ± 0.10%), lysine (3.28 ± 0.07%), and phenylalanine (3.13 ± 0.06%) predominated in terms of content. They accounted for about 25% of the total amino acid content. It should be noted that the content of some essential amino acids (leucine, isoleucine, lysine, phenylalanine + tyrosine, threonine, valine, and histidine) slightly exceeds the FAO/WHO level (for adults). Conclusions. The fatty acid composition of leaves of the common pear variety Lisova Krasunya was studied using chromatography-mass spectrometry. Seven fatty acids were identified, of which four were saturated (palmitic, stearic, arachidonic, and heneicosanoic acids) and three were unsaturated (α-linolenic, linoleic, and palmitoleic acids). Among the unsaturated fatty acids, α-linolenic acid dominated, and among the saturated fatty acids, palmitic acid dominated. The amino acid composition of the leaves of the common pear variety Lisova Krasunya was studied using ion-exchange liquid chromatography. Sixteen amino acids were identified, among which glutamic, aspartic acids, and leucine dominated. The studies confirm the promise of further phytochemical research on the leaves of the common pear variety Lisova Krasunya and the possibility of using the plant's raw materials as a source of amino and fatty acids.