DETERMINATION OF ORGANIC ACIDS IN FLOWERS OF SOME SPECIES OF MEDICINAL PLANTS BY GAS CHROMATOGRAPHY WITH MASS SPECTROMETRY (GC/MS) METHOD

Abstract

Introduction. Organic acids are one of the main substances of primary synthesis, present in plants in high concentrations. They play an important role in human life, are a source of energy, building material, pH regulator. Organic acids have anti-inflammatory, bactericidal effects, normalize the activity of the digestive system, improve appetite, regulate the secretion of bile and pancreatic juice, have antiseptic and detoxification properties, and have found wide application in cosmetology. The aim of the research was to study organic acids in the flowers of some little-studied species of medicinal plants. Research Methods. The material for the research was the flowers of nasturtium (Tropaeolum majus L.), curly mallow (Malva crispa L.), meluca mallow (Malva meluca Graebn.) and marigolds (Tagetes patula L.), which were harvested on household plots in the Ternopil region. For experimental research, raw materials from the 2025 harvest were used. The determination and quantification of individual organic acids in the raw materials under study was carried out on an Agilent 6890N/5973inert gas chromatography-mass spectrometry system (Agilent technologies, USA). The identification of organic acids was carried out by comparing the retention times of standards (oxalic, maleic, succinic, itaconic, malic, α-ketoglutaric, citric and isocitric acids) and using the NIST database. Results and Discussion. The GC/MS method identified and quantified the following individual organic acids in the flowers of marigold, nasturtium, mallow, and mallow melyuka: oxalic, malonic, fumaric, citric, isolimonic, succinic, and malic; α-ketoglutaric, cis-aconite, salicylic, levulinic, and maleic acids were not detected. In the flowers of nasturtium, curly mallow, and meluca mallow, citric acid dominated, the content of which was 1481.98 μg/g (58.32 % of the total amount of identified organic acids), 1813.31 μg/g (52.00 %) and 1484.84 μg/g (47.45 %), respectively. In marigold flowers, malic acid prevailed – 950.30 μg/g (52.93 % of the total amount of identified organic acids). The content of citric acid in marigold flowers was 444.27 μg/g (24.75 % of the total amount of identified organic acids). Slightly smaller amounts of malic acid were found in the flowers of nasturtium, curly mallow, and meluca mallow – 707.66 μg/g (27.86 % of the total amount of identified organic acids), 474.66 μg/g (13.87 %) and 430.60 μg/g (13.76 %), respectively. Conclusions. The qualitative composition and quantitative content of individual organic acids in the flowers of marigolds, nasturtium, mallow and meluca mallow were determined. The dominant organic acid in nasturtium, mallow and meluca mallow flowers was citric acid (1481.98 μg/g, 1813.31 μg/g and 1484.84 μg/g, respectively); in marigold flowers – malic acid (950.30 μg/g). The highest total content of individual organic acids was found in mallow flowers (3421.50 μg/g), the lowest – in marigold flowers (1795.23 μg/g), which is almost 2 times less.