Vol. 58 No. 3 (265) (2024)

N-Tert-butoxycarbonylglycyl-(S)-β-imidazolyl-α-alanine and N-tert-butoxycarbonylglycyl-(S)-[4-allyl-3-(3'-hydroxypropyl)-5-thioxo-1,2,4-triazol-1-yl]-α-alanine dipeptides, previously not described in the literature, were synthesized using the activated ester method for classical peptide synthesis. The structures of these synthesized dipeptides were confirmed through NMR spectroscopic analysis. The antifungal activity of initial non-protein amino acids and synthesized dipeptides was studied by choosing wide spread pathogenic and conditionally pathogenic fungal strains as test fungi: Aspergillus versicolor 12134, A. flavus 10567, A. candidus 10711, Penicillium chrysogenum 8190, P. aurantiogriseum 12053, P. funiculosum 8258, Alternaria alternata 8126, Ulocladium botrytis 12027, Aureobasidium pullulans 8269. The antifungal activity of the initial (S)-β-imidazolyl-α-alanine amino acid is notable against the P. aurantiogriseum 12053 and U. botrytis 12027 fungal strains. N-Tert-butoxycarbonylglycyl-(S)-β-imidazolyl-α-alanine dipeptide demonstrates a strong inhibitory effect specifically on the P. aurantiogriseum 12053 strain, with a similar level of inhibition observed at a concentration of 0.6 mL (0.331 mmol/mL). The initial amino acid exhibited comparable inhibition at a higher volume of 0.9 mL (0.495 mmol/mL). In contrast, the (S)-[4-allyl-3-(3'-hydroxypropyl)-5-thioxo-1,2,4-triazol-1-yl]-α-alaninе amino acid effectively suppresses the growth of multiple strains, including P. aurantiogriseum 12053, P. funiculosum 8258, U. botrytis 12027, and A. pullulans 8269, when tested at 0.9 mL (0.495 mmol/mL). The corresponding N-tert-butoxycarbonylglycyl-(S)-[4-allyl-3-(3'-hydroxypropyl)-5-thioxo-1,2,4-triazol-1-yl]-α-alanine dipeptide also shows significant inhibitory effects similar to those of (S)-[4-allyl-3-(3'-hydroxypropyl)-5-thioxo-1,2,4-triazol-1-yl]-α-alaninе.

Acid treatment of natural zeolites is often used to "improve" their porous structure and properties, which are also affected by thermal treatment. The influence of hydrochloric acid solutions with concentrations up to 2 N and calcination at temperatures up to 800℃ on the structure and properties of clinoptilolite-containing tuff from the Armenian Nor-Kohb deposit, selected for the creation of new bactericidal zeolite filter materials for purification and disinfection of water from various sources, was studied by the chemical analysis, powder X-ray diffraction patterns, adsorption of water, benzene and nitrogen. It was found that an acidic environment leads to significant dealumination (Si/Al atomic ratio increases from ≈5 to ≈9.4) and changes in cationic composition without decationization leading to a decrease in the adsorption capacity for water vapor; acidic solutions do not lead to amorphization of the zeolite microporous crystal structure, but gradually dissolve it. Acid treatment also "opens" micropores for large non-polar nitrogen molecules, increases the adsorbing surface area and causes changes in the mesopore system, leading to an increase in their size. Heating leads to the transformation of partially dehydrated zeolite into the metastable phase of heulandite B at 457℃ followed by possible formation of zeolite-like mineral wairakite (500℃) and formation of anorthite-like feldspar (600℃); the content of the amorphous phase increases with increasing temperature, but the zeolite crystalline structure is maintained even after annealing at 800℃. The specific porosity of heulandite (0.17 cm³/g) is maintained up to a temperature of 700℃, the adsorption capacity of micropores for water vapor (>4 mmol/g) does not change up to a temperature of 500℃, at higher calcination temperatures, the volume of micropores available for nitrogen molecules and the surface area also decrease, and the average diameter of nano-sized pores increases.

An investigation into the precise ethylenediaminetetraacetic acid (EDTA) crystalline structural report was initiated, as there appeared to be some ambiguity regarding the accurate notation of EDTA as a neutral molecule or a zwitterion. As a result, the first and foremost article reporting EDTA in zwitterionic form was determined after a difficult confirmation. Additionally, crystallographic data of the zwitterionic EDTA itself and non-chelated salts thereof registered on the CCDC were also mentioned herein. This episodic knowledge will be fundamental for not only chemical education but also related science and technology in the future.

As the global population grows and ages, the incidence of cancer is rising.  Cancer treatment remains one of the most significant biomedical challenges of modern medicine. Current treatment modalities, including surgery, radiation therapy, chemotherapy, targeted therapy, and immunotherapy, have significantly improved survival rates for some cancers. However, substantial challenges persist across several fronts, which limit the efficacy and accessibility of cancer treatment. In recent years, the integration of herbal preparations alongside conventional chemotherapy has gained growing attention in cancer treatment. The investigation into the synergistic potential of herbal extracts combined with chemotherapeutic agents is of particular interest, as it could enhance their therapeutic efficacy while reducing adverse effects. This work aimed to evaluate the antitumor effect of plant extracts in the HeLa cancer cell line, study the possible mechanisms of action, and observe the effectiveness of the combined effect of plant extracts such as Inula helenium and Alchemilla smirnovii Juz. with chemical inhibitors of the arginase like L-NAME and nor-NOHA, targeting the metabolic pathways of nitric oxide synthase (NOS) and arginase. In our study, treatment with Alchemilla smirnovi Juz. resulted in a significant decrease in arginase activity compared to the control group. Similarly, treatment with Inula helenium also reduced arginase activity. This combination aimed to enhance the cytotoxic impact on cancer cells, potentially offering an effective strategy for combating breast cancer. Based on the data, we can conclude that targeting arginine metabolism and using plant-derived compounds holds promise for developing novel anticancer therapies.

The influence of L-Val and D-Val amino acids on a phospholipid bilayer, which serves as a physical model for the cell membrane, has been studied using the simultaneous small and large angle X-ray diffraction, as well as optical polarizing microscopy methods. It is shown that despite L-Val and D-Val amino acids having the same structure and differing only on their chirality, the effect of L-amino acids and, consequently, their permeability on the membrane is greater than that of D one. This indicates that the cell membrane exhibits a certain selectivity towards chiral molecules. Additionally, it was demonstrated that the hydrophobicity and hydration of an L- and D-amino acids also play a significant role on the interaction between the amino acids and the cell membrane. It is known that L-amino acids are more prevalent in nature than D-amino acids. This research was to explore the interaction of L- and D-amino acids with the phospholipid bilayer, which can serve as a physical model of the biological membrane, aiming at understanding the differences of their effects. This could help to explain the widespread presence of L-amino acids in nature and the scarcity of D-amino acids. The data obtained in this work suggest that this difference is likely due to the distinct mechanisms of interaction between L- and D-amino acids with the bilayer. Investigating the interaction of these amino acids with the phospholipid bilayer, which forms the essential structure of biological membranes, one can gain insights into the mechanisms of their interaction with biological membranes.

The etiology of Dupuytren's contracture (DC), a disease characterized by the thickening of the palmar aponeurosis, remains relatively understudied. Diabetes mellitus (DM) is identified as one of the risk factors for DC. The objective of the present research is to find out the relation of DM to the DC in the level of some essential enzymes. The object of the study was the hand's aponeurosis. The activities of adenosine deaminase (ADA) and glutaminase (GLS) enzymes were studied in the aponeurosis tissue homogenate. 15 individuals participated in the research and were divided into 3 groups per 5 persons: the group of individuals with only DC, the group consisted of individuals with DC and DM together (DC+DM), and the group of the relatively healthy subjects served as a control. The activity of GLS in the control group was equal to 0.92 ± 0.0180 IU/µg protein, and in the DC and DC+DM groups decreased down to 0.60 ± 0.03 IU/µg protein and 0.12 ± 0.012 IU/µg protein, relatively. On the contrary, the activity of ADA was in the control group of 0.057 ± 0.007 IU/µg protein and increased in the DC and DC+DM groups up to 0.47 ± 0.03 IU/µg protein and 0.94 ± 0.062 IU/µg protein, respectively. The results of the research indicated that these two enzymes are associated with the ethology and pathogenesis of DC development.