Home – Home – Jornals – Chemistry for Sustainable Development 2020 number 2

The review of the data on the chemical composition and biological activity of the genus Monarda L. represented by 20 species growing in North America is given. M. fistulosa L., M. didyma L. and M. citriodora Cervantes ex Lag. are successfully cultivated in various regions of Russia. The essential oils of Monarda are distinguished by the high content of phenols (67-89 %). Their composition depends on the species of Monarda , vegetation phase, site of growth, weather conditions. Under the conditions of a sharply continental Siberian climate (Novosibirsk), M. fistulosa has a high content (up to 4.16 %) of essential oil, more than in the Crimea and the North Caucasus. The phenolic complex contains flavonoids, anthocyanins and phenolic acids. Specific to the species of this genus is monardein, 3-O-(6-O- trans - p -coumaryl-β- D -glucopyranosyl)-5-O-(4,6-di-O-malonyl-β- D -glucopyranosyl)pelargonidine. The essential oil and extracts of Monarda have a high bactericidal, antiviral, antifungal activity, anti-inflammatory, analgesic, immunomodulatory, antioxidant, radioprotective, antioncological, etc . action. The oil extract of the aerial parts of M. fistulosa showed antimicrobial activity against pathogenic microorganisms: Staphylococcus aureus , Enterobacter cloacae , Streptococcus faecalis , Escherichia coli , etc . The aqueous-ethanolic and aqueous extracts showed high antiviral activity against influenza virus, subtype A/Aichi/2/68 (H3N2) (human) and A/chicken/Kurgan/05/2005 (H5N1) (birds). The extracts of Monarda also possess pronounced fungicidal properties. The activity of oil, water and water-alcohol extracts of M. fistulosa against the yeast-like fungus Candida albicans was very high. Thymol and thymoquinone from M. fistulosa are cytotoxic against certain lines of human tumour cells. The essential oil from M. citriodora and its main component, thymol, inhibit the proliferation of HL-60, MCF-7, PC-3, A-549 and MDAMB-231 cancer cells. Carvacrol also has an antioxidant and antitumour effect. Essential oil is used in the cosmetic and food industry to flavour vermouths, stabilize wines, and also as a natural flavouring agent, preservative and antioxidant instead of synthetic food additives. To expand the domestic market of raw materials, it is advisable to grow Monarda in culture.

The problem of sawdust utilization represents a challenge for almost all regions of Russia. At the same time, agricultural lands suffer from acute deficiency of organic fertilizers. The technology of sawdust composting using an association of microorganisms, which has been developed at the Irkutsk Institute of Chemistry SB RAS, allows, at least partially, addressing both of these problems. The paper deals with the main agrochemical indicators of the fertilizer produced from sawdust. Composting is carried out using different types of sawdust (deciduous and coniferous) over different years in various regions of Russia. It is shown that regardless of the substrate composition, time and place of composting, the fertilizer is stable in terms of composition and basic agrochemical indicators. The total amount of nitrogen, phosphorus, and potassium in the compost is comparable to that in high-quality organic fertilizers like high-moor peat, while the content of the mobile forms of main biogenic elements is higher. These substances, as well as humic acids, which are contained in the fertilizer, ensure the effective growth and development of plants during the vegetation season. The finished compost has a high cation exchange capacity and low hydrolytic acidity, which allow decreasing the removal of cations from plough layers. The advantages of the compost include close-to-neutral pH value and the absence of weed seeds and phytopathogens. The fertilizer does not contain phytopathogenic microorganisms and parasites, and the amount of toxic and hazardous substances is much lower than the maximum permissible concentrations established for soils. The use of this compost will not only increase the yield of agricultural crops, but also permit to eliminate the large-tonnage waste of timber processing enterprises.

Biodiesel is synthesized from five different types of vegetable oils (sunflower, mustard, linseed, corn and camelina). The yields of the target product, the physicochemical and low-temperature properties of the obtained biodiesel fuels are determined. The effect of the additive on the low-temperature properties of biodiesel and its blends with petroleum diesel fuel is investigated. It is shown that the low-temperature additive for petroleum diesel fuels is ineffective for improving the low-temperature properties of biodiesel. It is established that the efficiency of the low-temperature additive decreases with an increase in the proportion of biodiesel in the blend with diesel fuel. The expediency of using biodiesel as a blend component of commercial diesel fuels is shown. Recommendations on the use of “biodiesel/diesel fuel/low-temperature additive” blends as commercial diesel fuels of the Summer grade and Off-Season grade according to GOST (State Standard) 305-2013 “Diesel fuel. Technical Specification” are developed.

Analysis of the chemical and physical methods of water decontamination is carried out, the advantages and shortcomings of their application are revealed. A new approach to water treatment at centralized water-preparation stations is proposed. The approach involves the treatment of natural surface water, as the source of drinking water supply, by means of air floatation using ceramic membranes, coagulation (with aluminium sulphates or hydroxochlorides), filtration (through sand filters) to prevent biofouling and to enhance the efficiency of decontamination of purified transparent water after filtration, irradiation with ultraviolet light and subsequent water conservation by carbon dioxide (to restrain the growth and propagation of microflora in the distributing network). Additional decontamination of water from the city water supply in the case of the necessity to use it for drinking purposes may be carried out by boiling. This will allow complete elimination of the chlorination of piped water and the negative effects of this kind of treatment.

The samples of humic acids (HA) isolated from brown coal, both native and modified with hydrogen peroxide and n- butanol, were obtained and studied by means of elemental and technical analysis. The changes of structural parameters and the concentration of paramagnetic centres (PMC) of modified HA were revealed by means of ¹³C NMR, IR, EPR spectroscopy. The biological activity of native and modified HA was evaluated by means of phytotesting with the seeds of Iren wheat as an example. A trend to a decrease in the biological activity of HA with a decrease in PMC content was discovered. An increase in biological activity is connected with an increase in parameter F₁ depicting the relations between hydrophilic and hydrophobic elements in HA structure.

Mannich reaction of 6-methyluracil with salsolidine and substituted 1-aryl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolines was studied. The use of equimolecular amounts of reagents led to the production of new conjugates - 5-(1-(aryl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolyl)-2-methyl)-6-methylpyrimidin-2,4(1 Н ,3 H )-dions with 61-84 % yields. When studying the effect of these conjugates on the growth and viability of tumour cell lines (HeLa, HEp-2), it was found that the formation of tetrahydroisoquinoline derivatives with 6-methyluracil molecule does not contribute to the manifestation of cytotoxic effect.

Systematic studies in the field of the synthesis of ethers based on glycerol and polycyclic unsaturated hydrocarbons have been carried out. The reactions of glycerol addition to cyclohexene, bicyclo[2.2.1]hept-2-ene, tricyclo[5.2.1.0^2,6]deca-3,8-diene, tetracyclo [4.4.1^2,5.1^7,10.0^1,6]dodec-3-ene and their alkyl-substituted derivatives were carried out in the presence of a homogeneous catalyst - boron trifluoride etherate (BF₃ · OEt₂). It was revealed that the BF₃ · OEt₂ catalyst promotes the successful transformation of the above-indicated polycyclic olefins and their alkyl-substituted derivatives into glycerol monoethers in the yields of 70-87, 81 and 64-74 %, respectively. The effects of temperature, reaction duration, the molar ratio of initial components and the amount of the catalyst on ether yields were studied, and the optimal conditions for the synthesis of bi-, tri- and tetracyclic glycerides were determined. The synthesized ethers may be used as additives to synthetic oils.

A complex of medical and biological studies of the effect of 4-(hydroxyethyl)phenol ( p -tyrosol, aurol) on all life stages for the groups of different animals is considered. A substantial decrease in the level of mortality was revealed for each experimental group and at each life stage. The efficient action of aurol at the early life stages and during subsequent development of organisms was demonstrated. Aurol exhibits antioxidant properties, affects vascularization and neoangiogenesis and thus restores the nitroxidergic system of the brain, improves blood composition, strengthens the structures of the most essential systems of the organism, and decreases bird mortality at the early stage of life. The use of aurol in poultry breeding leads to early ovicell maturation in hen organisms, which causes an increase in egg-laying ability. In the cases of vaccination or diseases of birds, an increase in bird survival rate (90 %) is observed in the case of the treatment with known antibiotics in combination with aurol, compared to the reference group without aurol treatment (80 %). Neuroprotective action of aurol is exhibited as a sharp decrease in miscarriage rate during shearing pregnant goats. A positive effect of aurol application in cattle breeding causes the growth of more vigorous young individuals advancing in live weight by 5-7 % in comparison with the reference group. The long-term result of aurol action manifests itself in the animals of the experimental group during 25-30 days after injections and is explained by an increase in hemoglobin concentration and the high biological activity of blood serum. A substantial economic effect achieved during industrial tests of the maintenance of animals with the help of aurol at all stages of their life is the first example of an increase in productive longevity.

The decomposition of eudialyte concentrate was studied by means of sorption conversion in the 2 mass % solution of sulphuric acid. It was shown that eudialyte decomposes at a temperature of 80 ^оC with the formation of silica gel, while silica sol is formed at 20 ^оC. The efficiency of the sorption of refractory rare elements by the sorbent in the mode of silica sol formation increased in comparison with the mode of silica gel formation from 52.5 to 89.4 for zirconium, from 60.1 to 89. 2 for hafnium, from 7.4 to 85.1 for niobium, from 0 to 67.1 for tantalum, from 27.6 to 80 for titanium, respectively, with the provision of a high degree of extraction of rare earth elements (REE) - 82.9 %, including REE of yttrium and medium groups up to 86-89 %. The major part of the losses of niobium, tantalum, titanium and REE is determined by their inclusion in loparite and other accessory minerals that are untreatable under the studied conditions. It is assumed that a substantial increase in the sorption of rare elements of IV and V groups at 20 ^оC (in comparison with the results obtained at 80 ^оC) is due not only to the formation of silica sol but also to a decrease in the hydrolysis of the cations of these metals with the formation of their forms that are not sorbed by the sulphocationite. The features of decomposition of the eudialyte concentrate by the low-concentrated solutions of nitric and sulphuric acids were compared. The reasons providing the formation of silica sol during the low-temperature sulphuric decomposition of eudialyte are discussed. It is stressed that the studied method may be the basis of an efficient technology of eudialyte concentrate processing because the application of this method results in a decrease in acid consumption by a factor of 3-5 in comparison with traditional acid procedures. As a consequence, the amount of liquid wastes subjected to utilization is reduced, the effective specific radioactivity of the silica residue and the consumption of energy resources decrease.

The effect of temperature factor, polymer additives and magnetic field on the kinetics of sediment formation, pour point and microstructure of oil residue from high-paraffin low-resin oil is investigated for the purpose of developing the methods aimed at a decrease in the rate of formation of asphaltene sediments during oil transportation and storage. Independently of the temperature conditions of action, the introduction of additives into oil causes a decrease in the amount of the formed sediments. The maximal inhibiting capacity is that of DP2 additive causing a decrease in the amount of oil sediments almost by a factor of 9. The combined treatment of oil with magnetic field and the additive does not lead to an additional decrease in the amount of the formed oil residue and pour point.

Objective evaluation of the state of the environment may be made on the basis of the parameters of human health. The cities of Kirovsk, Apatity, and the Lovozersky district stand out among the cities and districts of the Murmansk Region for the diseases of the musculoskeletal system and urolithiasis. The population of these areas uses water formed within the giant alkaline massifs - Khibiny and Lovozero, containing the oxides of strontium, thorium, barium and rare earths. The solution - crystalline substance system was studied with the help of physicochemical modeling using the Selector software package. Environmental conditions and physiological parameters of the human organism were taken into account. Natural drinking water, gastric juice, a mixture of drinking waters and gastric juice were considered as the solution, while the newly formed phases in equilibrium with solution were considered as the crystalline substance. The chemical forms of the migration of elements including uranium were studied, and the conditions of mineral phase precipitation in the system natural waters - gastric juice under the conditions of reduced and increased acidity were investigated. It was demonstrated that the forms of element migration (Ni²⁺, Ba²⁺, Pb²⁺, Sr²⁺) remain carcinogenic or toxic at the temperature and parameters existing in the stomach. The proposed approach opens new opportunities in environmental and medical-ecological studies.

The composition and morphology of hydrolytic lignin obtained from sunflower husk are studied before and after alkaline modification. The sorption properties of hydrolytic lignin towards Cr(VI) ions were studied under static conditions (at the solid to liquid phase ratio 1 : 1200, and a temperature of 20 °C) from the aqueous solutions of potassium dichromate with different initial concentrations of Cr(VI) ions (0.05-1.0 mg/L). Sorption kinetics was studied, and the analysis of the integral kinetic curves of sorption was carried out in accordance with chemical kinetic models.

The reasons for the formation of nitrous oxide (a greenhouse gas with CO₂-equivalent equal to 310) at modern plants manufacturing weak nitric acid are analyzed. The amount of annual N₂O emission depending on the operating conditions of the ammonia converter and on the method of the removal of nitrogen oxides NO_х is estimated. A technological scheme of simultaneous low-temperature removal of NO_x and N₂O from exhaust tail gases is proposed, in which V/Al catalyst for the selective catalytic reduction (SCR) of NO_x with ammonia and Сs/Co₃O₄ catalyst for N₂O decomposition are used. Mathematical modeling of a 2-layer catalytic reactor is carried out; the charges of both SCR catalyst and N₂O decomposition catalyst are determined, which ensures compliance with environmental emission standards for all nitrogen oxides.