The article is devoted to the synthesis of new starch derivatives containing 2-aminoethyl sulfate. The study examined the influence of various parameters on the process of modification of polysaccharides, including reaction time, pH of the medium, temperature and concentration of reagents. Optimal reaction conditions were determined. The structure of the resulting product was analyzed using spectroscopy methods, including infrared spectroscopy. Additionally, the nitrogen content in the macromolecule was determined in order to assess the degree of modification, since nitrogen is often introduced into the molecule through amino groups, changing its properties and functionality. The influence of the amount of nitrogen on the formation of azomethine bonds and their distribution in the macromolecule was studied. It has been established that an increase in the number of sulfate groups in a macromolecule leads to an increase in its acidity, which can be an important factor when considering its biological activity. The results obtained represent an important contribution to the understanding of polysaccharide modification processes and their application in various fields of science and industry.

Pectin polysaccharides, due to the presence of reactive carboxyl functional groups in the structure, have a high complexing ability. This expands the scope of their practical application for the development of new biologically active substances. In this work, we propose the preparation of complex compounds based on sodium pectate and guanidine hydrochloride. By varying the molar amount of guanidine in relation to the acid groups of the polysaccharide matrix, samples were obtained that differ in the degree of substitution, the content of the amino derivative of the compound, and the inherent viscosity. The optimal ratio of the starting compounds was determined, at which the limiting amount of guanidine is bound to -COO- groups of pectin macromolecules. The structure of the resulting complexes was studied by FTIR spectroscopy. It has been established that the interaction of guanidine with polysaccharide carboxyls is accompanied by a change in the intensity of the absorption bands corresponding to the ionized acid group. Also, the binding of guanidine to the polysaccharide matrix through ionic bonds has been proven by carrying out the hydrolytic cleavage of the complex compound in an acidic medium. It is shown that with an increase in the hydrolysis time from 3 to 24 h, a gradual decrease in the initial degree of substitution of the complex compound is observed. The antimicrobial properties of polymer complexes with different characteristics against Staphylococcus aureus and Escherichia coli were studied.

Chemical modification of starch and cellulose was carried out using the periodate oxidation reaction.The structure of oxidized polysaccharides with different aldehyde group contents was studied by titrimetric analysis, X-ray diffraction analysis, and electron microscopy.According to the X-ray diffraction analysis data, amorphization of the structure of polysaccharides occurs in the process of periodate oxidation.Electron microscopy substantiated that as aldehyde groups grow in the macromolecular chain of starch and cellulose, there is a significant change in the morphology of polysaccharides.

В статье приведены результаты исследования ранозаживляющей активности и параметров токсичности геля на основе гуанидинсодержащих производных пектина. Установлено, что разработанный 0,5 % гель гуанидин пектина обладает высокой скоростью заживления ран на 7 сутки — 82 %. Гель относится к VI классу относительно безвредных веществ, ЛД50 составила более 3000 мг/кг при накожном применении у крыс. Явлений раздражения кожных покровов в виде покраснения, шелушения, а также изменений шерстного покрова как локально на выстриженном участке, так и вокруг него не отмечено, гибели животных не выявлено. При изучении хронической токсичности установлено, что при ежедневных накожных аппликациях в течение 30 дней исследованные гели не оказывают токсического действия на количественный состав и морфологию периферической крови экспериментальных животных.

Introduction. Up to the present time, there are practically no studies on the relationship between the structural characteristics and biological activity of antimicrobial polymers synthesized by the chemical addition of guanidine groups to polysaccharide macromolecules. Therefore, there is a need to carry out the chemical modification of guanidine with natural polymers, in particular polyaldehyde pectin, and to conduct comparative studies of the antimicrobial activity of the obtained samples with different physicochemical characteristics.Aim. To conduct the synthesis of guanidine-containing pectin derivatives. In addition, to determine the influence of structural variations in the obtained samples on exhibiting antimicrobial properties.Materials and methods. The synthesis of guanidine-containing pectin derivatives consisted of the following stages: periodate oxidation of the polysaccharide, modification of guanidine using polyaldehyde pectin, and chemical reduction of azomethine bonds. The amount of guanidine in the obtained samples was calculated by acidimetric titration, the nitrogen content (N, %) was determined using a Eura EA (Italy) elemental analyzer. The рКα values of the synthesized compounds were found by the back titration method. Absorption spectra were analyzed on a "UV 1280" spectrophotometer (Shimadzu, Japan) in the range λ = 180–400 nm. IR spectra were recorded on a Vector-22 spectrometer in the wavelength range of 400–4000 cm-1 in KBr tablets (3 mg sample / 300 mg KBr). The molecular weight characteristics of the synthesized derivatives were determined by high-performance gel permeation chromatography on an Agilent 1260 Infiniti liquid chromatograph. The acute toxicity of guanidine-containing pectin derivatives was calculated by the Prozorovsky method. Comparative assessment of antimicrobial activity was conducted by agar diffusion method.Results and discussion. By varying the oxidation level of polyaldehyde pectin, synthesized compounds differ in the degree of substitution, guanidine content, molecular weight, and pKα value. It was found that the levels of the antibacterial and antifungal activity of the studied samples depend on the degree of substitution and the nature of the counterion. The antimicrobial effect increases with an increase in the quantitative content of guanidine groups in the macromolecular chain of pectin. Moreover, it was found that the change of low molecular weight Cl–, NO3– , F–, I– counterions by carboxylate anions leads to a sharp decrease in antimicrobial properties. Upon oral injection of the synthesized compounds to mice, it was found that all samples belong to the category of practically non-toxic substances (V-class).Conclusion. Comparative analysis of guanidine-containing pectin derivatives with different characteristics showed that the severity of the antimicrobial action of the synthesized compounds against bacteria and fungi of the genus Candida depends on the quantitative content of cationic groups and the nature of the counterion.

Взаимодействием диальдегид-производного полигалактуроновой кислоты последовательно с гидразидом изоникотиновой кислоты и этамбутолом получен конъюгат, содержащий гидразид изоникотиновой кислоты, присоединенный посредством азометиновой связи (20 ± 2 моль %), и этамбутол, присоединенный ионной связью (25 ± 2 моль %). В условиях in vitro на клинических штаммах M. tuberculosis и H37Rv, а также в условиях in vivo на штаммах Humanis и Bovis полученный конъюгат показал выраженную противотуберкулезную активность. При введении конъюгата крысам терапевтическая концентрация активных веществ (изониазида и этамбутола) в крови сохранялась дольше, чем их низкомолекулярных аналогов, что указывает на возможность пролонгирования их противотуберкулезной активности.

The article presents data on the synthesis and antimicrobial properties of guanidine-containing carboxymethylcellulose derivatives with different physical and chemical characteristics. The regularities of the reaction of nucleophilic substitution of aldehyde groups of modified Na-carboxymethylcellulose (Na-CMC) by guanidine under different conditions are studied. Based on the results obtained, it was found that the limit replacement of reactive electrophilic groups with nucleophilic reagent depends on the pH value of the medium, molar ratio of guanidine and the degree of oxidation of cellulose ester. By varying the reaction conditions and the number of aldehyde groups in the oxidized Na-CMC composition, the azometin derivatives differing in the content of nitrogen-containing fragments in the polymer chain were obtained. Chemical restoration of labile azomethine bonds was performed and water-soluble derivatives containing strong amino-bound guanidine groups were synthesized. The study shows and substantiates the influence of structural indices (degree of substitution, quantitative guanidine content, pKα values and nature of counterion) of macromolecular systems on antibacterial and antifungal properties. The developed approach of synthesis opens prospects for creation of antimicrobial derivatives with regulated physical and chemical characteristics and set biologically active properties.

Research objective is to study the stability and shelf life of Biomayrin capsules, which were obtained by chemical modification of high-molecular weight compounds by incorporation into polymers.Materials and Method: "Biomayrin" capsules weighing 600±6 mg containing isoniazid, rifampicin, ethambutol, polygalacturonic acid and calcium stearate, obtained by disk dosing into capsules No.0.The shelf life was set by the method of "accelerated aging" when the samples were stored in PVCA1 blister packs (20 capsules each) at the temperature of 60 0 С in the thermostat TV-80-1.The tests "Decomposability" of capsules and "Average mass and homogeneity by mass" were conducted in accordance with the requirements of the State Pharmacopoeia of the XIV edition.Experiments were conducted in at least three repetitions.Decompressibility of capsules was determined on PJ-3 Tablet Four-usage Tester (China).Isoniazid, rifampicin and ethambutol were quantitatively determined in solution by spectrophotometry (SF).The analysis was performed on SHIMADZU UV-1601, UV-VISIBLE spectrophotometer in 1 cm cuvette against the background of the solvent.The pH value was controlled with the EV-74 universal ionometer.Mathematical processing of the results was carried out according to General monograph.1.1.0013.15"Statistical processing of chemical experiment results" using standard computer programs MsExcel. Results:The results on properties of capsules at storage of 60 0 С and 25 0 С are shown, after dissolution the content of active substances (isoniazid, rifampicin and ethambutol) in preparations was within the limits of regulated norms (60-120 mg), at 60 0 С it is for isoniazid 101, 7-106.7 mg, at 25 0 С 100.1-106.0mg for rifampicin the regulated norm was 72-132 mg and at 60 0 С it was 94.2-92.2mg, and at 25 0 С it was 94.7-91.2mg, as well as ethambutol hydrochloride content was 60-120 mg and at 60 0 С it was 62.5-60.5 mg, and at 25 0 С it was 62.0-60.2mg. Conclusion:"Biomainrin" capsules with different expiration dates were investigated, and also the change of their quality according to the indicators "Active substance content" and "Dissolution" was found.It was shown that after the expiration of the shelf life there is a gradual decrease in the active ingredient content.

We carried out chemical modification of the natural biopolymer (xanthan gum) with sodium periodate. By varying the concentration of the oxidizing agent, dialdehydes of xanthan gum were obtained with degree of oxidation 16,0–44,0 mol%. New soluble nitrogen compounds were synthesized by reacting obtained dialdehyde polysaccharide derivatives with guanidine. Structure and composition of the prepared compounds were investigated by IR spectroscopy and elemental analysis for nitrogen content. We calculated amount of guanidine and degree of substitution in the synthesized products, which amounted 31,0–85,0 mol% and 10,5–25,5% respectively.Biological activity of the compounds in conditions in vitro was studied against pathogenic microorganisms (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella) at a concentration of 50 mg / ml. Research results revealed that the increase in the degree of substitution and the amount of guanidine in the polysaccharide lead to increased antibacterial action of the agents. Obtained water-soluble guanidine derivatives containing xanthan gum may be used as antibacterial agents for oral and external applications.

New water-soluble starch derivatives, pectin, and Na-CMC containing sulfamic groups were obtained through reacting sulfamic acid with dialdehyde polysaccharide derivatives. The structure and composition of the obtained compounds was studied by IR spectroscopy, elemental (nitrogen, sulfur), and x-ray diffraction analysis.Sulfamic starch derivatives, pectin, and Na-CMC with different content of sulfamic groups were obtained by varying the concentration of sulfamic acid against dialdehyde polysaccharide derivatives. The optimal ratio which was found is equal to –СНО : NH2SO3H = 1,0 : 2,5.The interaction speed of sulfamic acid with dialdehyde starch derivatives, pectin, and Na-CMC was studied.Study results of the antibacterial and antifungal effect of sulfamic starch derivatives' sodium salts, pectin, and Na-CMC. Biological activity of the obtained compounds was studied at different concentrations such as 10, 25, 50 mg/ml disk diffusion method against Gram-positive and Gram-negative bacteria and fungi. It was found that synthesized compounds do not exhibit antifungal activity against Candida albicans. Nevertheless, they have antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Proteus vulgaris, Streptococcus faecalis, Streptococcus pyogenes, and Streptococcus faecalis at a concentration of 50 mg / ml.The dependence of antibacterial action of the sodium salt of sulfamic starch derivatives, pectin, and Na-CMC from concentration is shown.Direct dependence of the antibacterial activity of drugs was established through the quantitative content of sulfamic groups in polysaccharides. Study presents the results on acute toxicity of sulfamic polysaccharide derivatives. Based on the study results they can be attributed to class V-practically nontoxic substances.

A process of acidic hydrolysis of natural polysaccharide of galactomannanfrom GleditsiaAquatica was studied on temperature changes and time constant. It is shown that the molecular weight of galactomannans, a ratio of galactose and mannose are decreasing with increasing of hydrolysis temperature. The processes of viscous flow of aqueous solutions of hydrolysedgalactomannan derivatives were investigated in different temperatures. It is shown that all of the studied systems were non-Newtonian fluids with pseudo-plastic type of viscous flow aperiodicities.Structure of aqueous solutions of the hydrolyzed galactomannan samples was estimated by values of average sizes of kinetic units to compare the mobility of the structural components and their sizes for concentrated systems.It is shown that the molecular structure of galactomannan is the main factor of determining the structure of their concentrated solutions. The size of associates is increased accordingly in increasing of the degree of hydrolysis, forming more larger but less stable associates of hydrolysedgalactomannans.

This paper’s main concern is with the investigation of the elution properties of water-soluble polysaccharides in Size-exclusion chromatography (SEC) using multiangle laser light scattering and differential refractive index detectors in aqueous solvents. Chromatographic data on influence of nature of solvent to the formation of polymer aggregates is presented. We have shown that in pure water as eluent the bimodal and multimodal chromatograms of Na-carboxymethylcellulose (Na-CMC) and arabinogalactans (AG) were received. This phenomenon indicates of presence of intermolecular enthalpic interactions in solutions. We found that aqueous eluents containing 0,1 M NaCl for Na-CMC and 0,14 M NaNO 3 for AG are preferred to prevent of secondary effects distorting of SEC separation mechanism.