ИСТИНА

The universal approaches were proposed to determine neuromediator exchange markers - biogenic amines, catecholamines and their metabolites, as well as inorganic and organic peroxides, and flavonoids. The first one includes the unique combination of obtaining highly fluorescent derivatives of the analytes as a result of the interaction of their peroxidase oxidation products with benzylamine and 1,2-diphenylethylenediamine (DED), with the application of first-order derivative fluorescence spectroscopy for the resolution of the derivatives spectra. The proposed procedures provided sensitive (3–200 nM), selective, and reproducible multiplex determination of the catecholamines and their metabolites in biological liquids and were successfully applied for the rapid simultaneous (20 samples per 15–30 min) screening of human urine and mice blood plasma. The same system was used for rapid screening analysis of pharmaceuticals with predictable set of flavonoids and as a detecting system for chromatographic analysis of raw plant materials extracts without preliminary pretreatment of samples. The combination of the peroxidase reaction of any flavonoid oxidation with peroxide with the following derivatization of the oxidation product with DED became the base for the determination of (1 – 100) μM of peroxides in water-organic media. The second approach is based on obtaining intensively fluorescing ternary complexes of the mentioned analytes with europium(III) and oxytetracycline. The procedures can be applied to determine neuromediators with the high sensitivity (down to 50 fM) in blood plasma and cells of healthy people and patients with neuroendocrinal and neurodegenerative diseases. The authors are grateful to RFBR for financial support (grants NN 17-53-50025 and 19-03-00901).