Abstract: The metallurgical industry is one of the cornerstones of contemporary chemical science and industry and it is developing rapidly in many countries. The widespread introduction of metal extraction, concentration and separation as the most productive methods entails the need to search for and create new effective metal extractants. Among the compounds, suitable for use as extractants, the most widespread are organic phosphites and phosphates, which allow performing extraction processes with good selectivity and efficiency. The purposes of this article include finalizing the optimal synthesis conditions and developing larger batches of 4,5-dimethyl-2-(2,2,2-trifluoroethoxy)-1,3,2-dioxaphospholane and 5,5-dimethyl-2-(2,2,3,3,4,4,5,5- octafluoropentoxy)-1,3,2-dioxaphosphorinane, and study of the extraction properties of the obtained phosphorus- containing heterocyclic compounds in the separation of uranium from the commercial desorbate. The synthesis of new representatives of the indicated polyfluoroalkylated five- and six-membered heterocyclic phosphorus compounds was conducted using the interaction of 2-chloro-1,3,2-dioxaphospholane with trifluoroethanol and the substitution–cyclization reaction of polyfluoroalkylated dichlorophosphite with 2,2-dimethyl- 1,3-propanediol. Reactions easily proceed in triethylamine–hexane or pyridine–diethyl ether systems at temperatures ranging between minus ten to room temperature, with the output of target heterocycles of 53–57%. The studies of extraction properties of synthesized poly-fluorinealkylated dioxaphospholane and dioxaphosphorinane show that the use of these phosphorus-containing heterocyclic compounds as extractants allows extracting a technically valuable metal up to 12.4 and 15.2%, respectively. Nitric and sulfuric acid solutions of commercial desorbate of hydrometallurgical production in Kazakhstan were used as feedstock in the extraction process.

Abstract: The use of inexpensive materials such as sorbents increases the competitive advantages of removing heavy metal ions, including nickel (II) ions, from aqueous solutions and wastewater. Such materials include active carbons – carbon sorbents. The oxidized carbon sorbent AD-05-2 and its original analogue have been used as the object of this research. The oxidation of carbon sorbent AD-05-2 was conducted using a solution of nitric acid and urea following a conventional method. Oxidation resulted in improvement of the textural characteristics of the carbon sorbent. The total pore volume increased, including the volume of micropores, which had a positive effect on the sorption properties of the obtained sample. This article studies the adsorption of nickel (II) ions by the oxidized carbon sorbent AD-05-2 and its original analogue. For both models, the total time of establishing adsorptive equilibrium in the system adsorbate–adsorbent was 4 hours, pH = 9,6, and the range of temperatures – 298–338 K. The obtained experimental data on the nickel (II) ion adsorption are processed in the software package Statgraphics Plus. Adsorption isotherms are described using parabolic regression models, which cover 98.86–99.99% of the experimental data. The adsorption of nickel (II) ions increases with temperature, as indicated by a higher value of the first derivative dA/dCp, apparently, due to accelerated external diffusion. A significant steep rise of the isotherms corresponds to the temperature of 338 K, which indicates the diffusion effect on the adsorption process. The estimates of the accuracy of regression models are provided by the mean square σ and absolute Δ errors. Autocorrelation of experimental data is estimated using Durbin – Watson (DW) test. The obtained regression models can be applied for calculating the optimum parameters of nickel (II) ions’ adsorption from aqueous solutions and process stream using the oxidized carbonic sorbent AD-05-2 and its original analog.

Abstract: The role of phototrophs is examined in alternative energy, with the main emphasis on unicellular algae. Particular attention is paid to the use of phototrophs for generating electricity using biofuel cells (plant and enzymatic biofuel cells are discussed). This study focuses on microbial fuel cells (MFC), which, along with electric power, allow obtaining biofuels and biohydrogen. This article explains the factors limiting the MFC power, and ways of overcoming them. For example, it seems promising to develop various photobioreactors in order to reduce the loss of MFC power due to overvoltage. The use of microphototrophs in MFC has led to the development of photosynthetic MFC (or PhotoMFC) through the design of autotrophic photobioreactors with forced illumination. They allow generating oxygen through photosynthesis, both in situ and ex situ, by recirculating oxygen from the photobioreactor to the cathode chamber. Artificial redox mediators can be used here, transferring electrons directly from the non-catalytic cathode to O2, formed as a result of the photosynthetic activity of algae. Biologically catalyzed cathodes have been proven to generate less power than chemical catalysts. It is noted, that the MFC installations with the micro-algae allow utilizing a wider circle of different connections – the components of effluents and withdrawals: organic acids, sugar, alcohols, fats and other substrata. The use of phototrophs for the production of biofuels is of special interest. Several different types of renewable biofuels can be produced from microalgae, the production of which can be combined with wastewater treatment, CO2 capture and production of various compounds.

Abstract: Bioremediation using microorganisms has a number of advantages over physical and chemical methods of water, soil and atmosphere purification. Microorganisms have a wide range of metabolic capabilities that enable them to convert, modify and utilize toxic pollutants for energy and biomass production. This article shows their participation in the decomposition of various industrial wastes, such as dyes, hydrocarbons, chlorinated aromatic compounds and pesticides, among others. Although the use of microorganisms is an environmentally friendly and promising way of solving environmental threats, many factors affect the effectiveness of bioremediation, such as the chemical nature of pollutants, their accessibility to microorganisms, the physical and chemical characteristics of the environment, as well as the interaction of the destructive organisms with each other. The search for new effective strains or the creation of superdestructors using genetic and protein engineering methods proves to be crucial under current circumstances. This task can be solved using such “tools” as genomics, proteomics, transcriptomics and metabolomics. These technologies require the integration of a huge amount of data, which cannot be achieved without the use of bioinformatics. Bioinformatics is used in microbial bioremediation in different ways: analysis of genome sequencing data, identification of protein-coding genes, comparative analysis to identify the function of unknown genes, automatic reconstruction and comparison of metabolic pathways, and study of protein–protein and protein–DNA interactions to understand regulatory mechanisms. This review aims to highlight various resources that store information about possible pathways of microbial metabolism involved in the biodegradation of petroleum products. The use of such information resources can become a starting point for many studies in bioremediation.

Abstract: Development of sustainable biotechnologies for deep processing of grain raw materials requires effective mechanisms of obtaining strong wort for alcohol production. To provide qualitative characteristics of biochemical composition and rheological properties of strong wort, it is necessary to select optimal enzyme systems and conditions for deep conversion of high-molecular weight polymers of the grain. Previous research has proven the efficiency of carbohydrases for processing grain raw materials. However, there is little evidence on the catalytic effect of phytase, including in combination with other hydrolytic enzymes, on the degree of hydrolysis of polymers in grain raw materials when preparing strong wort. This paper demonstrates the effect of proteases and phytases in a multi-enzyme composition, as well as the conditions of enzymatic processing of raw materials, on the rheological and biochemical parameters of strong wort. Wheat, rye and corn were investigated. The synergism of the combined effect of studied hydrolases, including phytolytic and proteolytic enzymes, contributed to an increase in polymer conversion in this grain raw material and the concentration of soluble dry substances of the wort by 1.5 times. Using the proteases and phytases in the multienzyme composition allowed the concentration of the following components in the wort to be increased: glucose – by 1.2–1.3 times; amine nitrogen – by 1.5–2.2 times; phosphorus ions – by 1.4–4.3 times. Additionally, in the wort samples, the content of amino acids in the free form increased by over 4 times. It is shown that the pretreatment of grain raw materials at a temperature of 80–90ºС for 6 hours and saccharification for 1–2 hours using a complete complex of enzymes containing α-amylase, glucoamylase, xylanase, protease and phytase, allows a strong wort with a dry matter content of over 30% to be obtained. Moreover, a significant decrease in viscosity was noted (particularly for rye wort – by 1.3–1.9 times). Our results confirm the essential role of enzymes exhibiting substrate specificity to protein and phytic polymers in grain raw materials.

Abstract: This article aims to develop a probiotic for animals and aquaculture based on the Bacillus toyonensis B-13249 and Bacillus pumilus B-13250 strains. The selection of a nutrient medium was conducted for cultivating the inoculum of these microorganisms. Several bacteria fermentations of the Bacillus genus were performed in biological reactors with a capacity of 15 and 250 l. A technology for obtaining a finished probiotic for animals and aquaculture was developed. The results indicate that L-broth is the most optimal nutrient medium for cultivating the studied strains. The cultivation of B. toyonensis B-13249 and B. pumilus B-13250 strains in fermenters revealed that sporulation begins after 4–8 hours of fermentation. In contrast to the vegetative medium, the fermentative medium helped the bacilli develop a higher optical density (the maximum value in the B. pumilus strain – 2.400±0.149), pH value (maximum value in the B. toyonensis strain – 8.483±0.609) and titer (at least 1010 CFU/g). After 20–24 hours of incubation, both strains of bacilli in the fermenter, almost completely pass into endospores, which serve as a signal for the start of biomass centrifugation. This was indicated by the following: from a 15 l fermenter – 83.3±6.1 g of concentrate, from a 250 l fermenter – 499.8±51.4 g. The number of bacilli in a concentrated state was at least 1·1011 CFU/g for both strains. Obtaining a finished preparation required mixing bacterial concentrates with maltodextrin to a titer of at least 1·1010 CFU/g. The number of bacteria in the preparation checked every month during the year, recorded no value less than 1·1010 CFU/g. Thus, L-broth is most favorable for growing the mother culture of the B. toyonensis B-13249 and B. pumilus B-13250 strains, and fermentative nutrient medium – for the cultivation in fermenters. The expiry date of the bacilli-based biological preparation is at least 12 months, during which the drug’s polycomponence, color and consistency are preserved, in addition to the bacteria titer (at least 1·1010 CFU/g) and their viability.

Abstract: This article aims to study the influence of different concentrations of calcium ions on the activity of transmembrane (tmAC) and soluble forms of adenylyl cyclase (sAC) in the cells of roots and stems of the plants of two types of potatoes. It compares and contrasts their stability to the agent of the annular rot Clavibacter michiganensis ssp. Sepedonicus (Cms) when exposed to its exopolysaccharides. The experimental results have shown that the reaction of tmAC from the roots and stems to exogenous Ca2+ was almost opposite in the plants of both types. In the root cells of the plants of the resistant types, 1 and 10 mM of Ca2+ have activated tmAC in a very intensive way. In the stem, the average concentrations of Ca2+ inhibited the tmAC activity, while the highest, 1 and 10 mM, did not affect it. the activity of tmAC taken from the root cells of the receptive type of plants was not activated significantly by the increased concentrations of Ca2+, whereas, in the stems, all the concentrations of Ca2+, tmAC activity increased substantially starting with 1 μM. Thus, the unequal reaction of adenylate cyclases of the potato plants of both types to different concentrations of exogenous calcium, testifies, most likely, the presence of several isoform of this ferment that differ in the sensitivity to calcium ions. At the same time, it is possible that the plants of both types may also differ in the spectrum of such isoforms. Since the influence of Cms exopolysaccharides significantly changes the sensitivity to the calcium ions of both forms of adenylate cyclases in the cells of plants of both types, it can be assumed that this feature is one of the mechanisms of these plants’ resistance to the pathogen.

Abstract: All over the world, miscanthus is positioned as an extremely promising and rapidly renewable cellulose- containing raw material for the production of a large number of substances of chemical and biotechnological synthesis. The Institute for Problems of Chemical and Energetic Technologies of the Siberian Branch оf the Russian Academy of Sciences has been developing its own methods of treating miscanthus using diluted solutions of nitric acid. While the amount of a waste solution (liquid phase) is 20 times greater than the target product — a solid phase -- intended for enzymatic hydrolysis and further microbiological synthesis of bioethanol, bacterial cellulose and other valuable products. The hypothesis states that a nitric acid solution after treatment with miscanthus, which was neutralized with ammonium hydrate (hereinafter referred to as the preparation), is a combined lignohumic fertilizer. Testing this hypothesis has required studying the growth-regulating activity of the preparation using the example of sowing pea seeds. The results show that, depending on the degree of dilution and the exposure time, the preparation acts in two ways: either as a stimulant or as a growth inhibitor. Thus, at a dilution rate of 1:10, the preparation acts as an inhibitor, and at a dilution rate of 1:1,000,000, its effect ceases. The working range includes the dilution rate between 1:100 and 1:10,000, when an increase in germination energy and rate is observed by 2–6% compared to the control and root growth is stimulated by 21–29%, i.e. an auxin-like growth-stimulating effect is observed. With prolonged endurance during the 4th day, the preparation showed a growth-inhibiting effect, indicated by the decrease in the germination energy and rate, the length of the stems and roots of the sowing pea. The new preparation showing growth-stimulating activity under certain conditions, supposedly confirms the hypothesis that it is a combined lignohumic fertilizer.

Abstract: The recent decades have witnessed a significant development and implementation of nanotechnology, including in various branches of agriculture. There is an active search for ways to obtain preparations for plant growing with nanoparticles that can be more rapidly involved in the metabolic processes of plants. This article aims to obtain a nanosized silica-humic preparation and its approbation on potato plants. As a source of humic substances, a liquid humic preparation BoGum (developed by the All-Russian Research Institute of Reclaimed Lands) was used, as a source of silicon – sodium metasilicate. Ultrasonic dispersion method was used for achieving the nanoscale of the samples. A silicon source was introduced in an amount of 0.1% (of SiO2) into BoGum, followed by the application of ultrasonic action for 5, 10, 15 and 20 minutes. The analysis of the obtained samples using a 90 Plus/MAS particle size analyzer has shown that with increasing dispersion time, the effective particle diameter changed insignificantly. At the same time, a redistribution of particles was noted: when the samples were exposed for 20 minutes, the number of smaller particles increased. After 5 minutes of treatment, the range of particle distribution was 115±13–830±23 nm, after 20 minutes of exposure, the particle diameter fell into two regions: 81±8–120±10 and 280±4–470±18 nm. Ultrasonic action contributed to the retention of the stable state of aggregation of the obtained preparation, larger microbiological activity and larger content of humic acid in comparison with the silica-humic preparation, obtained without the application of an ultrasound. The new nanosized silica-humic preparation has been tested on potato plants. Treatment of tubers before planting, followed by foliar spraying of vegetative plants, has contributed to an increase in potato yield by 18.7%. Changes were noted in the content of mono- and polysilicic acids in the soil, as well as the accumulation of silicon in the tops of potatoes when using silicahumic preparations by 0.96% of absolute dry mass on average.

Abstract: This article aims to study the influence of the culture of the Bacillus thuringiensis var. thuringiensis 888 on the quality of the vegetative mass of Origanum vulgare in terms of the number of antioxidants and flavonoids, yield and composition of the essential oil. The research material included a liquid spore culture of the B. thuringiensis 888 strain, samples of oregano: sample no. g-4, containing 52.0% carvacrol in essential oil; No. 2 containing 59.85% α-terpineol; No. 1 with a predominant content of germacrene D (21.5%) and β- caryophyllene (19.4%). Soluble carbohydrates in the plants were determined using M.S. Dubois’s method, flavonoids – spectrophotometrically at 420 nm following R.A. Bubenchikov’s method. The total content of antioxidants was determined using the reduction of iron(III) chloride to iron(II) chloride. The essential oil content of Origanum vulgare was determined by using hydrodistillation following A.S. Ginsberg. Gas chromatography was used to determine component composition of the essential oil. The results show that treating the O. vulgare samples with the spore culture of B. thuringiensis 888 strain culture does not significantly affect the accumulation of terpenoid quinones, tochromanols and water-soluble antioxidants in leaves. It has been shown that treating oregano with an ordinary liquid spore culture of the B. thuringiensis 888 strain promotes the formation of a persistent tendency towards the accumulation of reducing sugars in the vegetative mass of plants — up to 30.8% compared to the control. Treating plants with a culture of B. Thuringiensis 888 strain promoted an increase in the essential oil content in O. vulgare plants of the sample no. 1 by 2.4 times, as compared to the control and did not significantly affect the essential oil content of the samples no. 2 and no. g-4. The sample no. g-4 was the most resistant to treatment with entomopathogenic bacteria, and the content of linalool and caryophyllene oxide in essential oils decreased by 44.6 and 37.1%, respectively, and linalyl acetate by 4.3 times compared with the control, as well as the accumulation of α-terpineol by 86.1%.

Abstract: The paper examines the biodegradation rate of cocamidopropyl betaine by bacteria of the genus Pseudomonas and activated sludge. The following microorganisms were taken as destructor strains: Pseudomonas fluorescens TR (VKPM B-4881), Pseudomonas putida TP-19 (B-6582), Pseudomonas stutzeri T (B-4904), Pseudomonas putida TSh-18 (B-2950), Pseudomonas putida TO (B-3959), Pseudomonas mendocina 2S (B-4710), Pseudomonas oleovorans TF4-1L (B-8621) and activated sludge obtained at activated sludge reactors of a Kuzbass plant. Biooxidation of surfactant samples was carried out in 250 cm³ glass flasks, placed into an incubator shaker, at a constant temperature of 30ºС for pure cultures and 18ºС for activated sludge. The destructor strain should reduce the surfactant concentration to safe values within a minimum time interval. Pseudomonas stutzeri T (B-4904) and Pseudomonas fluorescens TR (B-4881) strains provided the shortest half-life of the surfactant under study – 2.5 and 2.6 days, respectively. For Pseudomonas putida TO (B-3959), Pseudomonas putida TSh-18 (B-2950) and Pseudomonas oleovorans TF4-1L (B-8621) strains, these values amounted to 3.0, 4.5 and 4.9 days, respectively. The maximum half-life of the surfactant under study was demonstrated by Pseudomonas mendocina 2S (B-4710) and Pseudomonas putida TP-19 (B-6582) microorganisms – 5.5 and 6.0 days, respectively. The maximum biodegradation of the surfactant was observed under its exposure to the biocenosis of microorganisms. Over 14 days, the concentration of cocamidopropyl betaine decreased to 0.27% of its initial concentration. The efficiency of Pseudomonas bacteria as destructors of surfactants was demonstrated. Bacteria of this genus exhibit a shorter generation time and a higher rate of biomass growth when compared to other strains and a shorter period of adaptation to surfactants when compared to activated sludge. Capable of reducing surfactant concentrations to safe values in a minimum time interval, Pseudomonas strains can be used as an effective agent in the development of technologies for wastewater purification from amphoteric surfactants.

Abstract: Germination is an environmentally friendly and convenient approach to enhancing the biochemical potential of food plant raw materials. The nutritional value of raw materials and the functional properties of protein contained therein can be significantly improved by activatying the inherent enzyme system. Bioactivation not only increases the amount of water-soluble protein fractions, but also promotes accumulation of free amino and fatty acids and easily soluble reducing sugars. We used flax seeds as a source of essential polyunsaturated fatty acids, dietary fibres, complete protein, polypeptides and lignans to support the most important physiological functions of the human body. The aim was to study the dynamics of macronutrients in the process of short-term germination of flax seeds by chemical and spectroscopic methods. Flax seeds were germinated in laboratory conditions in special trays at a temperature of 18–20 ºС for 5 days with periodic moistening. Visual changes occurring in flax seeds at all stages of short-term germination are demonstrated. The periodicity of changes in the main macronutrients of flax seeds is shown. It is concluded that, during the studied period of germination, the principal hydrolytic decomposition of seed storage proteins was incomplete, leading to a permanent decrease, first of all, in the content of proteins and protein nitrogen. Based on the changes in the lipid content and acid number, the intensity of the peaks associated with functional groups in the lipid region, in particular, the band at 1748 cm-1 assigned to stretching vibrations of C=Ogroups of fatty acids, no degradation of storage lipids at an early stage of germination was assumed. The accumulation of soluble substances during the studied germination period is demonstrated, including watersoluble protein compounds, as well as water-soluble polysaccharides and products of their hydrolytic degradation. Sprouted flax seeds are a valuable ingredient for producing healthy foods.

Abstract: Scaling biosynthesis of bacterial nanocellulose (BNC) allowed samples of composite paper with an increased proportion of BNC to be obtained. This work aims to study BNC samples and bleached soft wood kraft pulp (BSKP) composite paper with a ratio of components varying across a wide range: 10:90, 30:70, 50:50, 60:40, 70:30, 90:10. The method of paper manufacturing was chosen based on the determinations of strength and deformation properties of composite samples with the BNC:BSKP ratio of 20:80. Surface application of BNT on BSKP handsheet provided for an increase in the strength values (tear resistance – by 37%, burst index – by 17%) and deformation characteristics (tension stiffness – by 66%, fracture work – by 8%, breaking length – by 4%) compared to a reference sample. The formation of composites is confirmed in all samples. Scanning electron spectroscopy revealed that paper composites comprise interlaced micro BSKP and nano BNC fibres. As the proportion of BNC in composites elevated, densification of the structure was observed due to an increased fraction of cross-linked nanosized elements. IR spectroscopy indicated the resemblance of cellulose structure in all samples. It was found that an increase in the degree of polymerisation of composite paper is directly proportional to an increase in the BNC amount in the samples. The filtering ability of composite paper samples against microorganisms in the culture liquid of the Medusomyces gisevii Sa-12 producer was studied. It should be noted that yeast retention is achieved with 70% BNC in the paper composite. The presented properties of the new material determine prospects for its use in filtering microorganisms.

Abstract: Despite their efficiency, existing methods to dispose of drilling fluids used in the construction of oil and gas wells (chemical treatment of spent solutions, thermal method, thickening) are often expensive and unsustainable. Basidiomycota are natural xylotroph destructors that process lignocellulosic substrate – one of the most stable biopolymers in nature. Prospects for using enzyme preparations based on Basidiomycota as biodestructors of organic substances are evident due to the high efficiency and zero-waste production. The aim was to obtain an enzyme preparation based on the Trametes hirsute MT-17.24 Basidiomycota strain and evaluate its ability to biodegrade polyanionic cellulose, used as a viscosifier for drilling fluids in the construction and repair of oil and gas wells. Screening of cellulase activity of the following strains was carried out: Fomitopsis pinicola MT-5.21, Fomes fomentarius MT-4.05, Lactarius necator, Schizophyllum commune MT-33.01, Trametes versicolor It-1, Trametes hirsute MT-17.24, Trametes hirsuta MT-24.24. To obtain the enzyme preparation, the T. hirsuta MT-17.24 strain was selected, which demonstrated the highest coefficient of cellulase activity (10.9). A medium for solid-phase cultivation of this strain was selected. Enzymatic activity of the enzyme preparation was studied on a model drilling fluid. A 10-hour experiment showed that the use of a 1% enzyme preparation leads to a decrease in the plastic viscosity of the drilling fluid from 16 to 8 mPa·s. The research results demonstrate the efficiency of enzyme preparations based on Basidiomycota in the biodestruction of polyanionic cellulose.

Abstract: Using the example of oil road bitumen grades BND 100/130, BND 130/200 and BND 70/100, this article studies the transformation of oil dispersed systems under various logistic schemes of operation. This research focuses on the influence of the conditions for storing road bitumens of different grades on their physical and mechanical properties and group hydrocarbon composition during transportation from the manufacturer to the consumer. The results show that a change in the physical and mechanical properties of road bitumens during high-temperature storage is related to the changes in the group hydrocarbon composition due to the hydrocarbons autooxidation and destabilization of the colloidal structure of dispersal systems. The conditions for storing bitumen with a minimum change in its quality indicators have been determined. It has been established that storage of bitumen under atmospheric conditions allows preserving its original properties without significant changes. There is evidence that nitrogen purging significantly reduces the effect of homolytic processes leading to the transformation of oil dispersed systems during further transportation from the manufacturer to the consumer. Experimental data confirm that of all basic physical and mechanical properties of bitumen, “the depth of penetration of needle” is the most sensitive index, while the “softening temperature” index, frequently used for quality control of bitumen, is inertial. Determining the change in penetration, depending on the duration of storing bitumen, has required formulating a special equation. It has been established that when storing road bitumen at a temperature of 180 ºС, for each hour the index of the penetration depth of the needle at 25 º decreases by 0.8 units. Organizational and technical measures have been determined to ensure the stability of the road bitumen quality during manufacture, storage and transportation to consumers.

Abstract: Diagnosis of complex injuries, such as splinter fractures and wounds, skull injuries accompanied by internal injuries that are inaccessible to visual control, presents the greatest difficulties during X-ray examination. Therefore, it is relevant to develop a drug that can help localize the site of a pathological lesion with high accuracy, relying only on the results of an X-ray study, which is possible when a reference point (substance) is applied to the patient’s skin. A radiopaque contrast compound based on an iodinated polymeric matrix with iodine as the contrasting component and polyguanidine as the carrier has been proposed to be used as a reference point substance. The choice of this class of polymers stemmed from the fact that a positive charge is localized to a greater extent on the carbon atom of the guanidine group, which allows loading iodine anions into it. Protonation of pure guanidine with hydroiodic acid has helped obtain guanidine hydroiodide. This finding was confirmed by IR spectroscopy methods (a decrease in the intensity of bands in the region of 1,380, 880 cm−¹ in comparison with guanidine, as well as broadening of the band of stretching vibrations of amino groups characteristic of guanidine salts) and X-ray phase analysis. Polyhexamethylene guanidine hydroiodide was synthesized based on hexamethylenediamine and iodine-containing guanidine salt using melt polycondensation. The results show that the aqueous solutions of samples under study absorb X-radiation and are the X-ray-positive substances (exposure radiation dosage E = 0.04 mSV).

Abstract: Acetamides are building blocks for the synthesis of compounds containing pharmacophores in their structure, manifesting a diverse range of biological activity. The drugs based on these substances possess antidiabetic effect and inhibit blood coagulation. Some of them act as chemosensitizers (i.e., cancer cell inhibitors). However, the full potential of these compounds remains to be fully accomplished. In a previous study, we synthesised acetamides with the RCONHCH (R´) CCl3 general formula (where R = CH₃, CH₂Cl; R´ = C₆H₅, C₆H₄CH₃, C₆H₄OCH₃, C₆H₄OH) and studied their acid-base behaviour. The NH-acidity of the studied acetamides is controlled by the polar effects of substituents. In this paper, the potential biological activity of the previously obtained acetamides is calculated, and the dependence of their biological potential on the NH-acidity values is elucidated. Prediction of biological activity was carried out using the PASS software. An analysis of the types of biological activity occurring in all compounds allowed us to determine a linear dependence between the probability of biological potential and the value of dissociation constant.