Russian Chemical Bulletin最新文献

The graft polymerization of acrylamide and methyl methacrylate onto a mixture of collagen and chitosan in an acetic acid dispersion in the presence of the complex of triethylborane with hexamethylenediamine has been studied. It was found that monomer conversion depends on the molecular weight of chitosan and the nature of the monomer, while the resulting terpolymers have a cross-linked structure. The models of hydrogel scaffolds based on terpolymers of collagen—chitosan—(meth)acrylic monomer were developed and water absorption and stability in buffer solutions were determined for these materials. The cytotoxicity of the obtained scaffold models was assessed using the MTT assay on human dermal fibroblast cultures. The results suggest that some samples are promising materials for regenerative medicine.

The review is devoted to one of the most popular polysaccharides at present, namely, chitosan and new composite materials with chitosan as one of the components. The main methods of chitosan fabrication, as well as the factors affecting the characteristics and properties of this polysaccharide are considered. The leading areas of chitosan application and the directions for the design of new composite materials based on this biopolymer are highlighted. The primary applications relate to medical materials and food biotechnology, where the unique structure of chitosan allows the creation of functional polymeric materials with predictable properties. The most demanded materials are scaffolds based on chitosan with various additives, biocompatible non-woven fibrous materials for bioengineering, and food packaging films with antibacterial properties.

Polymethine dyes (PDs) possessing unique photophysical and photochemical properties are widely used as probes or sensors for studying biomolecular systems. This review systematizes the results of our studies of the interaction between PDs and biomolecules (DNA, albumins, etc.) as part of research of certain biological objects. The fluorescent and photochemical properties of PDs are considered and the potential of application of these compounds as probes/sensors for biomolecular systems is assessed. In particular, interactions of cationic PDs with DNA and other biomolecules and those of anionic and cationic PDs with proteins, as well as the applicability of PDs as sensors in biomicellar systems and the application of molecular docking in studies of the interaction of PDs with biomolecules are discussed. It is demonstrated that improvement of PD probes based on deeper understanding of structure–property relationships, the development of specialized sensors for solving various biomedical problems, and further investigations of elementary photochemical processes occurring in the PD complexes with biomolecules still remain key areas of the development.

This review considers the results of research carried out in the past years at the Division of Chemical Enzymology of the Department of Chemistry of the Lomonosov Moscow State University on the development of bioluminescent test systems and their applications in ecology and biotechnology. Luminous bacteria were used as bioindicators in the screening of a large group of mycotoxins and for the selection of enzymes for their detoxification. Cells expressing pH-resistant thermostable firefly luciferase from Luciola mingrelica were used for the first time to study the kinetics and mechanisms of action of various antibiotics and other lytic agents on viable cells of prokaryotic and eukaryotic cells.

A simple and efficient method for producing lactate test strips was proposed, based on a one-step dropwise modification of screen-printed electrodes with three-component membrane-forming mixtures containing an enzyme, a mediator, and a polyelectrolyte. Compositions of mixtures for co-immobilization of lactate oxidase and mediators (potassium hexacyanoferrate(iii) or hexaammineruthenium(iii) chloride) in a chitosan membrane were developed. An increase in both the chitosan content (up to 0.1 vol.%) in the mixture and the signal registration time (up to 10–15 s) helped to expand the linear range of the test strips into the region of high lactate concentrations (up to 30 mmol L⁻¹). The applicability of the test strips for the lactate concentration determination in whole blood matrix was demonstrated, and the prospects for non-invasive lactate detection in sweat were considered. Thus, a method for manufacturing a biosensor was developed allowing simplification of the sensor production process and achieving optimal characteristics of biosensors for analyzing biological fluids.

Optimum conditions were selected for the preparation of new phenols: azo dyes of various compositions, namely, 2-phenyldiazenyl-4-(2-phenylpropan-2-yl)phenol and (2,6-dibromo)phenyldiazenyl-4-(2-phenylpropan-2-yl)phenol. Nucleophilic substitution with 3- and 4-nitrophthalonitrile was carried out using the synthesized dyes to form 3/4-[2-phenyldiazenyl-4-(2-phenylpropan-2-yl]phenoxy- and 3/4-[2-(2,6-dibromo)-phenyl)diazenyl]-4-(2-phenylpropan-2-yl)phenoxyphthalonitriles. The metal complexes were synthesized by template condensation in a solution of the corresponding phthalonitrile with zinc or magnesium acetate. The compositions and structures of the synthesized compounds were confirmed by mass spectrometry and NMR, IR, and electronic absorption spectroscopy. The spectral and luminescence properties were studied, the yield of singlet oxygen generation of the synthesized phthalocyanines was determined, and the acid-base properties of the synthesized complexes were investigated.

A series of aminobisphenol ligands containing different substituents both on the aromatic moieties and at the central nitrogen atom were synthesized by the Mannich reaction. The reaction of dilithium derivatives of these ligands with gallium trichloride affords the corresponding ONO-type gallium monochloride complexes. The replacement of the chlorine atom by a tert-butoxide moiety allows the preparation of reactive complexes, which efficiently initiate the ε-caprolactone polymerization. The activity of the synthesized complexes as polymerization initiators was studied. The structures of three aminobisphenols and three gallium complexes were determined by X-ray diffraction.

The reaction of S-(1S,2R,3S,5R)-2-formyl-6,6-dimethylnorpinan-3-yl thioacetate with chlorine dioxide in a pyridine—water solution was studied. The oxidative cleavage of the C—C bond between the carbonyl carbon and α-carbon atoms of the starting 2-formyl thioacetate of the pinane structure afforded new polyfunctional derivatives, (3S)- and (3R)-2-keto-3-sulfonic acids and 2-keto-3-chloro-3-sulfonic acid. The structure of the latter compound was determined by X-ray diffraction. The antifungal activity of the starting thioacetate and its keto derivative was evaluated against micellar forms of the fungi Aspergillus niger and Fusarium oxysporum and the yeast fungi of the genus Candida.

The reactivity of α-alkyl-α-nitroacetophenones with 1,2-phenylenediamines and o-aminophenols in acidic medium was examined. The reaction pathway depends on the catalyst used and provides access to the corresponding benzoxazoles, benzimidazoles, and quinoxalines via the aza-Nef-type reaction.

The applicability of the empirical charge model DENR (dynamic electronegativity relaxation) accounting for the inductive effect to the description of electrostatic interactions in compounds relevant to medicinal chemistry was assessed. Using a representative set of biologically relevant molecules selected from the PDBbind refined set, parameters of the DENR model were optimized to achieve the best fit to the reference molecular electrostatic potential (MEP) values calculated at the RHF/6-31G* level of theory. The results obtained using the DENR model and certain popular charge models aimed at reproducing the quantum chemical MEP values at RHF/6-31G* were compared. The cases were established where the DENR model provides better description of the electrostatic component of the energy of molecular interactions than the models that do not include the inductive effect. The scope of applicability of the DENR model was determined.