Nanodispersions based on silver nanoparticles (Ag0) are synthesized In the presence of polymer complexones (copolymers of N-vinylpyrrolidone (VP) with p-methacryloylaminobenzoic (MABA-Na) and p-methacryloylaminosalicylic acid (MASA-Na)). The spectral and morphological characteristics of the nano-dispersions are investigated using ultraviolet (UV) spectroscopy and atomic force microscopy (AFM); the minimum energy (Eg) of electron transfer from the valence band to the conduction band of the metal is estimated; and the influence of the nature of the chelate unit on the band gap Eg, as well as on the size of spherical nanoparticles is shown. The reduction of silver ions in water in the presence of copolymers VP-MABA-Na and VP-MASA-Na, due to fairly good screening, makes it possible to obtain spherical nanostructures with a diameter not exceeding 200 nm. In the case of Ag0/VP-MASA-Na, massive dense oval-shaped aggregates are formed, which consist of small densely packed nanostructures. The silver-containing dispersions Ag0/VPрMABA-Na and Ag0/VP-MASA-Na tested against E. coli, P. aeruginosa, and S. aureus bacteria show pronounced antimicrobial activity, significantly superior to the activity of the reference drug, Protargol.

An impedance technology or conductometric method in microbiological control is an indirect culture method for the determination of microorganisms using measurements of the impedance, i.e., electrical resistance to an alternating current in a growth medium as its chemical composition is transformed by the growth and metabolic activity of microorganisms. Traditional pharmacopoeial methods (double-layer agar method, surface inoculation, submerged cultivation) are used in practice for analysis. The conductometric method and the ATP-luminescent method for determining the total number of microorganisms can be used as alternative methods that significantly reduce the time of analysis and the amounts of consumables. The possibility of using impedance technology (conductometry method) for the determination of the total number of aerobic microorganisms in samples of medicinal plant raw materials with high levels of microbial contamination was examined by us. The aim of the study was to determine the total number of aerobic microorganisms in 1 g (mL) of herbal medicinal raw materials by impedance conductometric and pharmacopoeial cup agar methods. The results from determining the number of aerobic microorganisms using the cup pharmacopoeial and conductometric methods agreed with a correlation coefficient of 0.964.

The “microbiological purity” criterion is an important quality attribute of non-sterile drugs and excipients in the pharmaceutical industry. The impedance conductometry method of microbiological analysis (ICMMA) is based on monitoring of changes in the impedance (resistance to alternating electric current) of liquid growth medium resulting from the living activity of microorganisms contained in the analyzed sample. The aim of this work was to determine the possibility of using ICMMA for determining the total number (TN) of aerobic microorganisms in natural excipients. As a result, the TNs determined by conductometric and pharmacopoeial two-layer agar methods converged with a correlation coefficient of 0.95. This allowed the conductometric method to be recommended as a routine method for determining the TN of aerobic microorganisms when analyzing the microbiological purity of excipients intended for pharmaceutical production.

O-Alkyl hydrazinecarbothioates, which are potential building blocks in the synthesis of heterocycles and antimicrobial agents, were obtained from primary alcohols in 38–89% yields by a one-pot method. The obtained compounds are characterized by thione-thiol tautomerism in a solution. An experimental screening for antibacterial and antifungal activity of hydrazinecarbothioates was performed, the highest activity was found against B. cereus and St. aureus strains.

Copolymers of 2-dimethyland 2-diethylaminoethyl methacrylate with 2-deoxy-2-methacryalamido-D-glucose and N-vinyl-N-methylacetamide with 20 – 80 mol% of 2-dialkylaminoethyl methacrylate units and molecular mass (40 – 80)·10 3 Da were synthesized. Silver nanocomposites based on these copolymers were obtained. The synthesized Ag-containing nanocomposites were found to exhibit antibacterial and antiviral activity.

Copolymers of 2-dimethyl- and 2-diethylaminoethyl methacrylate with 2-deoxy-2-methacryalamido-D-glucose and N-vinyl-N-methylacetamide with 20 – 80 mol% of 2-dialkylaminoethyl methacrylate units and molecular mass (40 – 80)·103 Da were synthesized. Silver nanocomposites based on these copolymers were obtained. The synthesized Ag-containing nanocomposites were found to exhibit antibacterial and antiviral activity.

Polymyxin B 1 conjugates with polyglutaraldehyde were synthesized using reductive amination. The synthesized polymeric antibiotic derivatives were tested for antimicrobial activity against Gram-negative and Gram-positive bacteria. Polymyxin B 1 was found to be stable under the reaction conditions. The main structural factors influencing the antimicrobial activity of these conjugates were the composition and structure of the polyglutaraldehyde polymer chain. The polymer-antibiotic conjugates were very soluble in aqueous solutions and organic solvents.

The condensation of the peptide antibiotic Polymyxin В1 with the vinyl alcohol copolymers containing aldehyde groups was studied. The structure and composition of the resulting conjugates were determined. The polymer derivatives of the antibiotic were shown to preserve their antimicrobial activity.

Methods for synthesizing new heterocyclic compounds based on 1,3,4-thiadiazoles were developed. It was shown that these compounds possessed pronounced antifungal activity and could be recommended for further investigation as potential antimicrobial agents with fungicidal activity.

A series of new 4-hydroxy-6H-oxazin-6-ones containing 2-(5-nitrofuranyl) and 2-(5-nitrothienyl) moieties were obtained. New nitrofuran and thiophene derivatives were synthesized by reacting these oxazines with mono- (EtOH) and dinucleophiles (phenylhydrazine). It was established that the synthesized compounds possessed pronounced bactericidal activity against Staphylococcus aureus and, in some cases, Escherichia coli strains.

Hydrogels of flax and hardwood pulp powders were prepared by regeneration from solutions in N,Ndimethylacetamide—LiCl. Silver (Ag) nanoparticles were intercalated into the pulp hydrogel matrices by reducing a solution of AgNO3 using trisodium citrate. The resulting samples were studied by wide-angle x-ray scattering, x-ray photoelectron spectroscopy, and scanning electron microscopy. The antimicrobial activity was determined against Staphylococcus aureus-16 and Escherichia coli. It was found that the hydrogels exhibited antimicrobial activity even with a low concentration of Ag nanoparticles.

This is a study of the colloidal properties of mycelia of Basidiomycetes. In this paper we have investigated the surface properties of Abortiporus biennis mycelium. Microelectrophoresis and viscometry were used as research methods. We have determined the optimum pH for the sorption and desorption of substances on the mycelium, and the isoelectric point of the mycelium. In isoelectric state the particle is at maximum compression, sorption of material is the least possible. Maximum sorption on the surface of the mycelium occurs at pH 6,9-7,5 and 6,1-6,5 in the low values of ζ-potential. In case of buffer solutions specific adsorption of anions prevails, indicating the selectivity of sorption on the surface of the mycelium.

Effect of carbohydrate fractions from mycelium of higher Basidiomycetes Fomes fomentarius and Ganoderma applanatum on Ehrlichs solid tumor growth was investigated. We present evidence, that administration of soluble fraction of Ganoderma applanatum results in significant Ehrlichs solid tumor growth inhibition. In tumor model insoluble fractions had weak antitumor activity. The aqueous extracts have been shown to have a stimulative effect on functional activity of reticuloendothelial system when it was administrated intraperitoneally. However, the soluble fraction had more significant effect on macrophage activation.

Подобраны условия глубинного культивирования базидиомицета Flammulina velutipes (Fr.). P. Karst. Из мицелия гриба выделены растворимая и нерастворимая углеводные фракции в соотношении 1 : 12, содержащие 65.3–84.0% редуцирующих веществ, 7.5–10.0% белка и незначительные минеральные примеси. Основной углеводный компонент мицелия и фракций – глюкоза (53.6% в растворимой и 78.8% в нерастворимой фракции). В растворимой фракции обнаружено высокое содержание маннозы 23.6% и галактозы 18%. Полученные фракции оказывали стимулирующее действие на функциональную активность макрофагов, зрелых клеток системы мононуклеарных фагоцитов – центрального звена клеточного иммунитета, причем растворимая фракция проявляла более выраженный активирующий эффект.

The ability of yeast exoglycans (from Cryptococcus laurentii, Cr. luteolus, and Sporobolomyces albo-rubescens) to absorb copper and lead ions has been studied. The sorption isotherms have been obtained, which indicates that the mechanism of interactions in the system polysaccharide-metal is complex. For the majority of the glycans, the absorption selectivity was considerably higher in the case of copper, as compared to lead. The observed discrepancy in the effects of pH and temperature on the absorption indicates that the bonds mediating ion absorption by glycans are of different nature. In conclusion, yeast exoglycans are efficient sorbents of copper and lead ions, and lutelan is the most active exoglycan in this respect.