Proceedings of the YSU B: Chemical and Biological Sciences

Vibration pathologies are one of the pressing issues in medicine and biochemistry. It is known that under the influence of vibration, the content of amide groups of proteins in tissues increases, which is one of the biochemical indicators of the organism. It has been shown that amidation occurs to a lesser extent in brain proteins of old rats exposed to vibration than in young rats. When Trifolium pratense L. flowers are added to the animals' diet, the level of amidation during vibration in old rats also decreases to a lesser extent than in young rats. However, in both cases, the level of amidation occurring is reduced by half under the influence of the plant. Based on these results, the use of T. pratense plant material is proposed as a means of reducing the negative impact of vibration on the body.

L-arginine metabolism has emerged as a central regulatory axis in cancer biology, integrating metabolic reprogramming, immune modulation, and tumor microenvironment remodeling. Cancer cells frequently rewire arginine uptake, synthesis, and degradation pathways to sustain proliferation, evade immune surveillance, and adapt to metabolic stress conditions. This metabolic flexibility is enabled through coordinated regulation of key enzymatic nodes, including argininosuccinate synthase 1, argininosuccinate lyase, arginase isoforms (ARG1 and ARG2), and nitric oxide synthases, which collectively control intracellular arginine availability and its downstream signaling outputs. In the tumor microenvironment, arginine metabolism becomes a competitive interface between malignant cells and immune populations. Tumors exploit arginine depletion through increased arginase activity in myeloid-derived suppressor cells and tumor-associated macrophages, leading to impaired T-cell activation and suppression of anti-tumor immunity. In parallel, nitric oxide generated from arginine metabolism exerts concentration-dependent effects that can either promote tumor progression through angiogenesis and survival signaling or induce cytotoxic stress and apoptosis at higher levels. Additionally, polyamine biosynthesis derived from arginine catabolism further supports tumor growth, chromatin remodeling, and resistance to cell death. This review provides a comprehensive synthesis of L-arginine metabolic pathways in cancer, with a particular focus on their roles in tumor-associated inflammation, apoptotic regulation, and angiogenesis. We also discuss therapeutic strategies targeting arginine dependency, including arginine deprivation therapies, arginase inhibition approaches, and emerging combination immunometabolic strategies, as well as key resistance mechanisms such as argininosuccinate synthase 1 re-expression and metabolic rewiring. Collectively, L-arginine metabolism represents a multifunctional metabolic hub that connects tumor progression with immune regulation and offers multiple promising therapeutic entry points in oncology.

The White Stork (Ciconia ciconia L.) is one of the best monitored bird species in the Western Palearctic, with national censuses conducted roughly every ten years since 1934. In Armenia, systematic monitoring between 2005 and 2016 documen-ted breeding pairs in seven of the country's eleven administrative regions – Ararat, Armavir, Aragatsotn, Yerevan, Lori, Shirak, and Vayots Dzor – with no confirmed breeding records from Kotayk Region. During Armenia's participation in the 8th International White Stork Census in June 2024, seven breeding pairs were confirmed across three settlements in Kotayk (Yeghvard, Kanakeravan, and Mrgashen), all nesting on electric poles. This represents the first documented breeding occurrence of the species in this region. We report the details of this finding and discuss two non-exclusive explanations: genuine range expansion associated with Armenia's broader national population increase in 2024, and improved survey coverage relative to earlier monitoring efforts that did not include Kotayk. Continued monitoring will be needed to determine whether this represents a stable and expanding foothold for the species in the region.

Adenosine deaminase (ADA) is an enzyme important in mammalian purine metabolism and in maintenance of the immune system. Its activity increases in pathological conditions, resulting in decrease in the concentration of anti-inflammatory adenosine, with aggrаvation of inflammation. Therefore, the discovery and development of ADA inhibitors represent an actual biochemical and pharmacological task. We tested approximately 100 new synthesized aniline and piperazine derivatives for their ADA inhibitory activity. The present study describes the inhibition of ADA by one of the aniline derivatives tested, D011_186. The compound exhibited potent inhibitory activity with an IC₅₀ value of 40±1.1 µg/mL. The interaction between the ADA and D011_186 was investigated using UV-Vis and fluorescence spectroscopy techniques. Differential UV-Vis spectroscopy analysis of the ADA-compound interaction revealed no significant difference between the optical absorption of their mixture relative to the sum of their individual spectra. Next, 2D and 3D fluorescence spectroscopy methods were applied to assess ADA-compound interaction. The individual fluorescence spectra of ADA and compound were compared with the spectrum of their mixture, however, no changes in the recorded fluorescence spectra reflecting their interaction were detected. Thus, although the compound D011_186 inhibits ADA activity it is not accompanied by a change in the orbitals of their optical electrons.

The effect of gallic acid (GA) and tannic acid (TA) on the antioxidant activity of white wines was studied based on sensory, physicochemical and DPPH assay. It was shown that GA exhibits pronounced antioxidant activity (R_s = 22.78%), while TA, at the same concentration, demonstrates a significantly stronger antioxidant effect (R_s = 68.21%) without altering the sensory properties of the wine. These findings suggest that both phenolic acids, GA and TA, may serve as promising natural antioxidant additives for enhancing the oxidative stability and preserving the quality of white wines.