The aim of the present study was to obtain new metal complexes of citrus pectin with cobalt ions based on potassium polygalacturonate and to prepare a new pharmacological composition (PC) PGKCo: PGNaCo (1:1) with antitumor activity based on potassium cobalt polygalacturonate (PGKCo) and sodium cobalt polygalacturonate (PGNaCo). The study of the effect of PGKCo, PGNaCo and PC on the cell viability of tumor cell lines of different genesis in vitro showed that the obtained compounds are soluble in water and exhibit selective cytotoxic activity against the tumor cell lines of human lung carcinoma A549, breast adenocarcinoma MCF-7 and cervical carcinoma M-HeLa, with no significant toxic effect on normal human cells. The possible mechanism of action of the investigated PC on M-HeLa cancer cells was investigated. The mechanism of action of PC was found to be associated with cell cycle arrest in the G0/G1 phase and the induction of apoptosis through the mitochondrial pathway. The results obtained indicate the potential for the non-toxic compounds (PGKCo, PGNaCo and PC) to be developed as drugs for the complex treatment of oncologic diseases.

Problem statement. Currently, many leading companies in the field of electronics, radio engineering, and aerotechnics are concerned about the depletion of non-renewable resources such as platinum, gold, silver, indium and even the more common lithium, nickel and copper, which they actively use in their products. The design and synthesis of nanostructures with controlled morphology has attracted the attention of many researchers and engineers, since it is much more efficient to deposit a small amount of metal on the surface being used than to create a part entirely from this metal. There are several main methods for producing nanostructures on a surface: chemical deposition, electron beam lithography, pulsed laser deposition, electrochemical deposition and other methods. Electrochemical deposition is worth highlighting among all methods, because it makes it possible to obtain such surfaces relatively cheaply and on a large scale and control their morphology by changing deposition conditions, such as time, potential, solution pH, etc. Purpose of the study. Obtain nickel-containing nanoparticles on glassy carbon by electrodeposition from an aqueous solution of biopolymer complexes of sodium pectate with divalent nickel; to determine the influence of electrodeposition conditions, namely, the duration of deposition and the content of Ni(II) ions in sodium petectate complexes, on the morphology of the resulting surface. Results. Studies have been carried out of the influence of electrodeposition conditions on the morphology of the resulting glassy carbon electrode surface. It was found that biopolymer ligands act as a stabilizing agent for the formation of nickel-containing nanoparticles instead of a nickel-containing layer. The standard sizes of the resulting nanoparticles are in the range of 20 – 90 nm. The nickel content in the complexes, as well as the deposition time, proportionally affects the amount of deposited nanoparticles, but has little effect on their sizes. Practical significance. The results obtained make it possible to use them for controlled electrodeposition of nickel-containing nanoparticles on conducting surfaces in the development of nonlinear optical devices, LEDs, diodes, transistors, logic gates, sensors and other electronic devices.

The biodegradation of petroleum by Aspergillus niger strain AM1 VKM F-4815D is studied. Visual observation and gas chromatography–mass spectrometry (GC-MS) showed that petroleum undergoes partial destruction, but cannot serve as the only source of carbon: the culture medium must contain glucose. An interesting fact is the change in consistency and hardening of petroleum under the influence of A. niger. This allows us to consider the possibility of using the strain for bioremediation of soils and waters contaminated with petroleum. No less interesting is that even earlier the strain was found to be able to metabolize a number of toxic phosphorus compounds, including even white and red phosphorus. However, most organic solvents have a noticeable toxic effect, slowing growth in the presence of glucose and not becoming sources of carbon in the absence of glucose.

Based on the method developed in this study for obtaining water-soluble PGKCo and PGNaCo, which we had previously synthesized, a pharmacological composition (PC) containing simultaneously the macroelements K and Na, as well as the trace element Co, was obtained for the first time. The effect of polygalacturonates and PC on the viability of cells of tumor lines of various origins was studied in vitro. It was shown that the target products have water solubility, low toxicity (LD50 above 5000 mg kg–1) and selective cytotoxic activity against the tumor cell line of human lung carcinoma A549, breast adenocarcinoma MCF-7 and cervical carcinoma M-HeLa. The results obtained confirm the prospects for further research into water-soluble metal complexes and PC based on pectin biopolymers for the treatment of cancer.

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The biodegradation of oils by the strain Aspergillus niger AM1 VKM F-4815D was studied. Visual observation and gas chromatography-mass spectrometry showed that oil is subject to partial destruction, but cannot serve as the only source of carbon — the culture medium must contain glucose. An interesting fact is the change in consistency and hardening of oil under the influence of A. niger. This allows us to consider the possibility of using the strain for the bioremediation of soils and waters contaminated with oil. No less interesting is that, even earlier, the ability of the strain to metabolize a number of toxic phosphorus compounds, including even white and red phosphorus, was established. However, most organic solvents have a noticeable toxic effect, inhibiting growth in the presence of glucose and not becoming carbon sources in the absence of glucose.

For fourteen years our team has been working on the research of biodegradation, primarily of phosphorus-containing compounds. The world's first biological detoxification of elemental — white and red — phosphorus was carried out. We obtained mold fungi cultures, which transform a substance of the first hazard class white phosphorus into harmless phosphate. This is the first example of the inclusion of white phosphorus into the biospheric cycle of the phosphorus element. In the future, the results of the research may become the basis for effective methods of preventing and eliminating pollution by toxic phosphorus compounds. Therefore, the research is of interest both for practical application and from the point of view of fundamental science.

In this paper, we report a simple and cheap method for obtaining iron-containing nanoparticles on the surface of glassy carbon by electrolysis of an aqueous solution of a sodium pectate complex with iron. Such transition metal complexes have previously been proposed as homogeneous or heterogeneous (for example, in a composite) catalysts for a number of electrochemical reactions. Here we demonstrate a different approach, using the complex as a precursor to obtain nanoparticles.

New pharmacological compositions based on water-soluble pectin metal complexes PG-NaCaFe and PG-NaFeCoCu (PG is polygalacturonate) in weight ratios of 6: 1, 9: 1, and 12: 1 promising for pharmacology and medicine as drugs for the treatment of both iron deficiency and pernicious anemia are developed. According to the testing results on males of the Sprague Dawley rat line in vivo , the most pronounced increase in the number of erythrocytes and hematocrit is observed upon the introduction of the composition with the 9: 1 PG-NaCaFe to PG-NaFeCoCu weight ratio indicating the highest efficiency of this complex drug.

Formation of stable complexes of pectin polysaccharides with Nifedipine hypotensive drug has been shown by IR and UV spectroscopy, stereochemistry of the complexes has been determined, their preparation conditions have been optimized. Features of thermal decomposition of pectin and the prepared complexes with Nifedipine have been studied by TGA/DSC. Obtained results provide scientific foundation to design new water-soluble non-toxic formulation of Nifedipine to expand the use of the drug in medicine.

Coordination biopolymers, namely, nickel complexes of sodium pectate, have been actively studied in recent years as promising representatives of non-platinum catalysts for proton exchange membrane fuel cells. The structure of coordination polymers consisting of natural precursors is complex and not entirely regular. It presents significant difficulties in determining the internal structure of coordination polymers. Identifiable electron paramagnetic resonance (EPR) signals of various Mn2+ units in sodium pectate manganese complexes have provided important structural information in systems similar in composition to nickel coordination biopolymers. In addition, the manganese complexes with the natural pectin polymers themselves are of interest as non-platinum PEMFC catalysts.

One of the promising directions in the development of catalysts for hydrogen evolution and carbon dioxide reduction reactions is the creation of coordination biopolymers incorporating noble metal ions. This work reports on a composite containing a sodium pectate complex with manganese, which exhibits catalytic activity towards these reactions. The overpotential for water reduction in the presence of the deposited nanocomposite was reduced by more than 1000 mV. Chromatographic analysis of the products of water electroreduction on the nanocomposite surface showed the presence of molecular hydrogen.

Sodium pectate derivatives with 25% replacement of sodium ions with nickel ions were obtained by carbonization to temperatures of 280, 550, and 800 °C, under special protocols in an inert atmosphere by carbonization to temperatures of 280, 550, and 800 °C. The 25% substitution is the upper limit of substitution of sodium for nickel ions, above which the complexes are no longer soluble in water. It was established that the sample carburized to 550 °C is the most effective active element in the hydrogen-oxidation reaction, while the sample carbonized up to 800 °C was the most effective in the oxygen-reduction reaction. The poor performance of the catalytic system involving the pectin coordination biopolymer carbonized up to 280 °C was due to loss of proton conductivity caused by water removal and mainly by two-electron transfer in one catalytic cycle of the oxygen-reduction reaction. The improved performance of the system with coordination biopolymer carbonized up to 550 °C was due to the better access of gases to the catalytic sites and four-electron transfer in one catalytic cycle. The (Ni-NaPG)800C sample contains metallic nickel nanoparticles and loose carbon, which enhances the electrical conductivity and gas capacity of the catalytic system. In addition, almost four-electron transfer is observed in one catalytic cycle of the oxygen-reduction reaction.

A number of nickel complexes of sodium pectate with varied Ni2+ content have been synthesized and characterized. The presence of the proton conductivity, the possibility of the formation of a dense spatial network of transition metals in these coordination biopolymers, and the immobilization of transition ions in the catalytic sites of this class of compounds make them promising for proton-exchange membrane fuel cells. It has been established that the catalytic system composed of a coordination biopolymer with 20% substitution of sodium ions for divalent nickel ions, Ni (20%)-NaPG, is the leading catalyst in the series of 5, 15, 20, 25, 35% substituted pectates. Among the possible reasons for the improvement in performance the larger specific surface area of this sample compared to the other studied materials and the narrowest distribution of the vertical size of metal arrays were registered. The highest activity during CV and proximity to four-electron transfer during the catalytic cycle have also been observed for this compound.

The formation of complexes of sodium polygalacturonate with the antimicrobial drug tetracycline was confirmed by UV spectroscopy, powder X-ray diffraction, and dynamic light scattering. The stoichiometry of the complexes with the maximum tetracycline content (6.68 wt.%) was determined. The morphological characteristics of the synthesized complexes were studied by scanning electron microscopy in comparison with the initial compounds.

The aim of this study was to evaluate the antianemic activity of water-soluble PGNaCaFe, a pectin metal complex containing iron and calcium ions for hematopoiesis in vivo. The study of antianemic activity was performed on Chinchilla rabbits of both sexes with an average weight of 2.2–2.5 kg using the Posthemorrhagic Anemia model. The effect of PGNaCaFe was studied after oral administration for 60 days at a dose of 126 mg/kg (with an iron content of 1.3 mg/kg). As a comparison, the well-known antianemic drug-analogue Tot’hema at a dose of 0.25 ml/kg (with an iron content of 1.3 mg/kg) was performed for the correction of the iron deficiency state of rabbits subjected to bloodletting. The results of hematological study of the PGNaCaFe antianemic activity compared to Tot’hema at the end of the experiment show an increase and normalization of blood parameters: the number of erythrocytes increased by 32,1 and 24,3%, hemoglobin concentration—by 38.4 and 40.2%, hematocrit—by 32.1 and 34.5%, respectively. The introduction of iron-containing preparations causes a decrease in the total iron-binding capacity of serum on days 40, 50, and 60 in the first experimental group of rabbits by 21.3, 2.3, and 3.2%, in the second group—by 24.2%, 18.7, and 3.8%, respectively. No pronounced side effects on the internal organs of rabbits were revealed during pathomorphological studies, what demonstrates the advantages of PGNaCaFe which confirms its prospects as non-toxic bioavailable and effective anti-anemic drug.

Atmospheric pollution with carbon dioxide is a serious environmental threat to the climate of our planet. We can find a way to solve it using the method of electrochemical reduction of CO2. This article presents the research results during which data were obtained on the formation of an iron-containing nanostructured surface of a glassy carbon electrode using the methods of electrochemical deposition and scanning electron microscopy, during which it was concluded that the longer the pectate complex with iron is deposited on the surface of the working electrode, the greater number of particles formed on its surface. The catalytic properties of the PG-NaFe complex in water were also tested using cyclic voltammetry when the solution is saturated with carbon dioxide. It was experimentally proved that the iron-containing complex PG-NaFe exhibits catalytic activity for the carbon dioxide reduction reaction in the course of this research. Method for the deposition of a sodium pectate complex with iron on the surface of a glassy carbon electrode without the use of expensive components was proposed based on the analyzed data.

Relevance of the research topic is due to the global trend towards the development of clean energy, in particular, the utilization of carbon dioxide. Recently, electrocatalytic reduction of carbon dioxide has been considered as a promising way to utilize carbon resources and produce sustainable fuels. Due to the limited energy efficiency, uncontrolled selectivity, low stability, and uncertain mechanisms of electrocatalytic CO2 reduction, there are still many complex problems to be solved. In this regard, current research in the field of electroreduction of CO2 is relevant. Sustainable and cheap catalysts need to be developed for the electroreduction of carbon dioxide. This paper presents a review on sodium pectate with manganese as a catalyst in the carbon dioxide reduction reaction. It was experimentally proven that sodium pectate with manganese exhibits catalytic properties in carbon dioxide reduction as the overvoltage was reduced by 400 mV. The stability of this complex was also tested for some time, the current for 8 hours increases, which means that sodium pectate with manganese can maintain its catalytic activity in the carbon dioxide reduction reaction for a long time. In the future, this complex can replace other more expensive catalysts.

This research studied the formation of sodium polygalacturonate complexes with the antimicrobial drug "Tetracycline". The formation was confirmed by IR, UV and NMR spectroscopy. It was shown that the complexes were formed by electrostatic attraction and hydrogen bonding. The complexes demonstrated a high degree of drug binding to the polysaccharide matrix with the maximum content of tetracycline (6.68 wt %). The study of the antimicrobial activity of obtained compounds against S. aureus, B. cereus, E. coli showed no decrease in the antimicrobial effect compared to source tetracycline. Thus, the future research towards the new design compounds based on studied complexes could make contribution to a new generation of drugs based on pectin biopolymers.