Our research focuses on the synthesis of 1,2,3-triazoles through 1,3-dipolar cycloaddition involving arylazides, acyclic active methylene compounds. The reaction demonstrates high efficiency when conducted in the presence of morpholine, resulting in 100% regioselectivity towards a single isomer. A theoretical study of this reaction can be conducted to gain insights into its mechanism and provide valuable information for its optimization. The study involves the use of computational methods, such as Density Functional Theory (DFT), to calculate the structures, energies, and properties of the reactants, intermediates, transition states, and products involved in the reaction. The calculations were performed using the Gaussian09 program with the DFT-D3/B3LYP-GD3BJ method.

Every year, peptide-based preparations are becoming more and more in demand in medicine. Therefore, identifying and researching new biomaterials that are sources of regulatory peptides is an urgent task. This study examines the epidermal secretion of African catfish (Clarias gariepinus) as a readily available raw material for the preparation of peptide complexes. In the history of peptide drug synthesis, this object was first investigated as a source for obtaining regulatory peptides with antioxidant activity. We applied a new approach to the process of isolation of biologically active peptide fractions, thus reducing the time and increasing the yield of the target product.

In this work, the antioxidant activity of the isolated peptide complexes was confirmed by two independent UV spectroscopic methods of quantitative analysis. These include a method for inhibition of adrenaline autooxidation in alkaline medium and a method based on the use of DPPH (2,2-diphenyl-1-picrylhydrazyl) to determine glutathione-equivalent activity. For a more precise quantification of the inhibitory activity of peptides, we applied methods and tools of the formal kinetics apparatus. The antioxidant activity of the complexes was determined over a wide range of concentrations and compared with the activity of commercial peptide drugs.

Thus, this work represents an in-depth study devoted not only to a comprehensive study of the process of isolating biologically active fractions of peptides. It also analyzed their antioxidant activity, which opens up the possibility of using these drugs for the treatment of severe forms of wound processes.

The modification of heterocyclic systems still remains one of the most promising areas in heterocyclic chemistry. Benzodiazepines (BZDs), representing a diverse class of heterocyclic molecules, have piqued the interest due to their use as anticonvulsant/anti-inflammatory/analgesic/sedative/anti-depressive/hypnotic medications, as well as anti-inflammatory/anti-HIV drugs. Particular attention was focused on the phosphorus heterocycle molecules fused with the rings of different sizes and bearing various hetero-atoms. Phosphoramidate class compounds with an amino group linked directly to the phosphorus atom have gained considerable attention due to their broad range of biological activity and agricultural application. To date, however, only non-condensed monocyclic 1,3,5,2-oxodiazaphosphol-2-oxides have been described.

Herein we report the synthesis of previously undescribed 4H-[1,3,5,2]oxadiazophospho[3,4-a][1,5]benzodiazepine-1-amino-1-oxides, comprising benzodiazepine and a fused five-member oxodiazophospholo cycle with four heteroatoms in the "a" position, which has made possible by phosphorylation of 1,3,4,5-tetrahydro-2H-1,5-benzodiazepin oximes with an equimolar amount of dimethylaminophosphoric acid dichloride. The chemical structures of the compounds were confirmed by IR, ¹H, ¹³C and ³¹P NMR spectral analysis. A series of simulations were run using the semi-empirical tight-binding computational approach GFN2-xTB to reveal the likely pathways leading to their formation.

The synthesized compounds obeyed Lipinski's rule, implying a high bioavailability, and assessment of their projected drug-like abilities revealed that they may have a strong anti-neoplastic potency and may serve as both substrates and inducers of cytochrome P-450 (CYP) super-family enzymes.

For many years, allenes have been considered very unstable molecules, which has caused a lack of knowledge of their chemical and synthetic applications in the scientific community. However, in the last decades these compounds have experienced great growth in the field of organic synthesis due to their interesting reactivity that allows a great variety of possible transformations. In particular, the allenol moiety is a special type of allene that exhibits a rich and fruitful reactivity.

On the other hand, metal catalysis allows the strict regulation of selectivity in chemical reactions which is crucial in organic synthesis because it enables the preparation of distinct molecules in a controlled manner. In this context, gold catalysis has been used for the cycloisomerization or oxycyclization of α-allenols showing useful levels of chemo-, regio-, and/or stereoselectivity.

We have recently achieved a gold-catalyzed bis[(trifluoromethyl)sulfonyl]ethylation of α-allenols, which allows the preparation of sterically congested bis(triflyl)enals. This sequence differs from the conventional reaction pathway of α-allenols under π-acid catalysis. In our case, Au(I) functions as a π-Lewis base catalyst rather than a π-Lewis acid to activate the allene.

In addittion, it should be also noted that the strongly electron-withdrawing (trifluoromethyl)sulfonyl (triflyl, Tf = SO₂CF₃) group confers a positive effect on the metabolic stability and lipophilicity of potential drugs important to the field of medicinal chemistry.

Some of the most extensively studied marine or estuarine bacteria belong to the genus Vibrio, with Vibrio cholerae being the most notorious species as it is the cause of cholera in humans. V. cholerae is found in tropical and temperate areas, and can be classified as a mesophilic bacterium with growth optimum around 37°C. One of the important factors in the activity and the stability of each enzyme is its physiological environment. A previous study on the secreted mesophilic enzyme Endonuclease I from the Vibrio cholerae genus (VcEndA), showed that its activity was strongly dependent not only on temperature, but also on NaCl concentration. Here we report a structural study on the mesophilic enzyme (VcEndA) using molecular dynamics simulations at different salt concentration (NaCl). The analysis of molecular dynamics simulations trajectories reveals that the enzyme is not tolerant and not sensitive to salt, since the profile of the rmsf as a function of different concentrations does not show a large difference in the mobility of the enzyme for high values of the NaCl concentration (450 and 650 mM). However, the most flexible regions of the enzyme are recorded under the concentration of 175 mM, which coincides well with the previous experimental work.

The synthesis of polymeric nanoparticles by two-step emulsion polymerization techniques is proposed for their application in metal recovery processes, particularly yttrium and europium.The particles will be functionalized with acrylic acid, fumaramide and curcumin at different percentages of solids content, (5, 10 and 15% p) to analyze their effect on the recovery of yttrium and europium rare earths in model solutions, and to establish the possible extraction mechanism. It is proposed to evaluate the efficiency of extraction and discharge of metal ions from polymeric materials, as well as to determine the pH conditions and the solid-liquid ratio that maximize the extraction and discharge of metal ions, thus seeking the substitution of liquid extractants used in the hydrometallurgical industry, which are expensive and highly polluting. Finally, a kinetic model that best fits the process will be proposed. The materials before and after extraction and discharge will be characterized by known techniques to evaluate structural and morphological changes of the polymeric particles

Thiazolyl-pyrimidine hybrid plays significant roles in the biological activities and SAR of thiazolylpyrimidines (Tzpd), thiazolopyrimidines and thienopyrimidines due the combination of the thiazole and pyrimidine pharmacophores. The study developed regression-based models for the prediction of antiplasmodial activity of 43 Tzpd hybrid obtained from the ChEMBL database. The molecular descriptors (145 features) were scaled down to 6 using the recursive feature elimination. The X- and Y-matrix were split into 34 train and 9 test sets using a split ratio of 0.20. Regression models were built using scikit-learn algorithms: k-Nearest Neighbours (kNN), Support Vector Regressor (SVR) and Random Forest Regressor (RFR)) to predict the pIC₅₀ of the test set. The models were evaluated using R², mean squared error (MSE), mean absolute error (MAE), root mean squared error (RMSE), p-values, F-statistic, and variance inflation factor (VIF). Of the 145 features calculated for the 43 TzPd, 6 molecular features: FCASA-, MNDO_LUMO, E_str, vsurf_HB1, vsurf_G and vsurf_DD12 (p < 0.05; VIF < 5) were found to significantly influence the antiplasmodial activity. Five-fold cross-validation performance scores of kNN, SVR, and RFR showed that the performance metrics of SVR (MSE = 0.052; R² = 0.610; MAE = 0.174; RMSE = 0.230; pIC₅₀(predicted) = 8.06 - 0.45vsurf_G + 0.37FCASA‒ - 0.42MNDO_LUMO – 0.20E_str + 0.30vsurf_HB1 – 0.38vsurf_DD12) outperformed models. The study developed predictive models and provided insights into the chemical features necessary for the optimization of thiazolyl-pyrimidine to enhance antiplasmodial activity.

A computational NMR approach for accurate predicting the ¹H/¹³C chemical shifts of triterpenoid oximes featuring the screening of 132 DFT methods was demonstrated. Efficiently synthesized dipterocarpol oxime was employed as a model compound. Six highest accurate methods from the screening generated the root-mean-square-error (RMSE) values in the range of 0.84 ppm (0.55 %) to 1.14 ppm (0.75 %) for calculated ¹³C shifts. For ¹H results, simple, economical 6-31G basis set unexpectedly outperformed other more expensive basic sets; and the couple of it with selected functionals provided high accuracy shifts (0.0617 ppm (1.49 %) ≤ RMSE ≤ 0.0870 ppm (2.04 %)). These computational results strongly supported the proton and carbon assignments of the oxime including the difficult ones of diastereotopic methyl groups, the methyl groups attached to an internal olefin, and diastereotopic a-protons.

A hybrid compound based on (5Z,9Z)-eicosa-5,9-dienoic acid and vanillin was synthesized in high yield (94%) using a new intermolecular cross-cyclomagnesiation reaction of aliphatic and O-containing 1,2-dienes catalyzed by Cp₂TiCl₂

Phthalocyanines are a group of synthetic molecules derived from porphyrin compounds. For decades, phthalocyanine molecules have been a very important object of study for the scientific community. Not only because of their ability to bind to a wide variety of metals and non-metals at the core of their structure, but also because of their recognised photochemical activity to generate reactive oxygen species (ROS), such as ¹O₂ and O₂^.-, via energy transfer and electron transfer reactions, respectively. These oxygen species have the ability to cause damage to bacterial cells, as well as assist in the elimination of malignant and tumour cells during the development of diseases such as cancer. In our study, we have synthesised via microwave several unsubstituted phthalocyanine molecules linked to different metals of the first transition series: Zn, Cu, Ni, Co, Fe and Mn. For this study several unsubstituted phthalocyanine molecules bound to different metals of the first transition series were synthesized via microwave. It was analyzed how the photochemical activity is modulated (UV-VIS spectrum, fluorescence, quantum yields of 1O2, free radicals, etc.) depending on the size and electronic configuration of the central metal. For this purpose, we have performed some theoretical calculations related to the energies of the excited states, and correlated them with the experimental results. Finally, the photobiological activity of phthalocyanines in DNA was carried out by using bacterial plasmid pBR-322 in agarose gel electrophoresis. This allowed us to obtain a general idea about which metals can provide the highest photosensitising ability in possible applications of Photodynamic Therapy.