Fine Chemical Technologies

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Vol 13, No 2 (2018)
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5-20 1149
Bismuth and its compounds have been known since ancient times and now are widely used in practice in various fields. Bismuth use in medicine can be traced back to the Middle Ages, and its wide application is due to its very low toxicity - for most bismuth compounds it is less than for sodium chloride. Bismuth and its compounds, in particular salts, are used in medical practice in the treatment of diseases such as spirochetosis, gastric and duodenal ulcer, leishmaniasis and coronaviral infection, as well as in cancer therapy. In addition to solid preparations liquid peroral pharmaceutical forms have been developed for the treatment of diarrhea, colitis, ulcers etc. Bismuth preparations are used in stomatology for the treatment of inflammatory diseases of paradontium. The review considers the syntheses and properties of bismuth complexes with natural and synthetic porphyrins, which are used in medicine and other fields of science and technology. Considerable attention is paid to the structure features of bismuth porphyrins complexes, their dimeric structures, and the influence of various extra ligands. The counterion nature and structure make a substantial contribution in solving the problem of complexes stability. The central bismuth atom in these complexes extends far above the plane of the macrocycle due to the large ionic radius. Thus, the counterions action on the conformation, physicochemical properties and stability of metal porphyrins complexes is shown. A separate section is devoted to unique and interesting properties of bismuth porphyrins complexes, such as fluorescence and color variation of crystals.
21-30 455
This work is dedicated to the synthesis of porphyrin metal complexes for creation of dyesensitized solar cells (DSSC). Three different dyes were synthesized - zinc complexes of porphyrins containing alkoxyl substituents: with symmetric structure (Zn-P1), as well as asymmetric (type A3B) with the introduction of a donor (Zn-P2) or an acceptor (Zn-P3) substituents via the 1,3,5-triazine fragment. The spectral characteristics of the synthesized substances are compared. For all the obtained dyes, geometry optimization and visualization of the electron density distribution were carried out using computational methods based on the density functional theory (DFT). The location of the frontier unbound molecular orbitals is more optimal when an acceptor substituent containing anchor groups is introduced via the triazine moiety. However, the use of ligands containing an anchor group simplifies the synthesis of the dye and opens up more possibilities for varying both the ligand and the introduced donor substituents. As a result, it was concluded that the spatial distribution of the dye, when applied to the electrode and, consequently, the number of its molecules per unit area of the semiconductor, can have the greatest effect on the efficiency of a cell using t he described compounds.
31-39 407
Here we examined the influence of polymyxin B, a lipopeptide antibiotic, on planktonic growth and biofilm of streptomycin-sensitive and streptomycin-resistant isogenic strains of bacteria Methylophilus quaylei on polypropylene and Teflon. Biofilm formation was quantified using crystal violet staining, determined by colony-forming unit and examined by light microscopy. It was found that of bacterial surface hydrophobicity affects the biofilm formation: biofilm formation of Methylophilus quaylei MT strain was better on such hydrophobic materials as Teflon and polypropylene. The minimum inhibitory concentration of polymyxin B for the used strains in planktonic and biofilm form was 1 μg/ml. The sublethal Polymyxin B in the concentration of 0.01 μg/ml stimulates biofilm formation and exhibits antibiofilm properties at the concentration of 0.10 μg/ml. Synergistic effect of polymyxin B and streptomycin on streptomycin-resistant strain M. quaylei SM was found.


40-50 492
Cocoyam (Xanthosoma sagittifolium (L.) Schott) is a tropical plant of the family of Araceas. Nigeria, China and Ghana are the countries that currently own most of the world production of this plant. In Colombia, there are not extensive crops of this plant, but it is used for animal feeding mainly. The plant has an aerial part with a high content of protein (leaves) and a tuber with an average starch content about 25% w/w. Compared to others starchy raw materials, this is a high value. Due to this fact this first-generation starchy material could be considered as a possible feedstock for the production of ethanol. Process design must ensure that the most advanced concepts are applied at the design and processing stage for every raw material to ensure efficient and more sustainable processes. For this reason, thermodynamic-topological analysis was used for the design of the stage of the produced ethanol purification. This work presents the process of ethanol production using cocoyam tuber. The software Aspen Plus v8.6 (Aspen Technology, Inc., USA) was used for the techno-economic assessment, and the Waste Reduction Algorithm (WAR) of the Environmental Protection Agency of the EE.UU. (EPA) was used to measure the environmental performance. The obtained production cost was 1,6 USD per kilogram, and the environmental impact was very low. This is an excellent incentive to promote the application of this feedstock to obtain a feasible alternative for the production of ethanol. Additionally, the use of thermodynamic-topological analysis in the design stage of the purification stage of the process proved to be very useful and easily applied.


51-55 464
The results of investigation on the effect of mechanochemical treatment of the diesel fraction on its physicochemical characteristics are presented. Mechanochemical treatment of the diesel fraction was achieved by creating a cavitation effect in the hydrodynamic regime. The studies were carried out in the range of pressure gradients up to 50 MPa, the number of treatment cycles varied from 1 to 5, the temperature of raw material at the apparatus inlet was 0 0С. It is shown that the effect of cavitation is manifested not only in the processing of high-boiling hydrocarbons, but also in a middle distillate directions. So, as a result of the cavitation effect, the density of the diesel fraction and its pour point decrease, and the fractional composition changes. It is suggested that these changes are associated with hydrocarbon degradation. The collapse of gas bubbles leads to a local increase in the temperature of the medium to 800 0C, which, in turn, leads to the destruction of hydrocarbons. Increasing the pressure gradient of the hydrodynamic flow enhances the noted effect. Increasing the number of treatment cycles reduces the effect achieved. A possible reason is the destruction of hydrocarbons formed in the first stage of processing and the formation of polycyclic and aromatic structures. The results presented in the article extend ideas about cavitation regularities in the hydrocarbon environment


56-63 466
The article considers a non-conventional approach to the synthesis of various polymorphic modifications of manganese dioxide. The approach consists in hydrothermal microwave processing of a reaction mixture containing potassium permanganate and hexamethylenetetramine. We emphasize the relevance of the work due to such MnO2 properties as catalytic and photocatalytic activity, its application in accumulators, supercondensers and biochemistry. We report on the first detailed study on the role of temperature, synthesis duration and pH value on the phase composition and morphology of nanocrystalline MnO2. We show that the phase composition of manganese dioxide is largely determined not only by temperature, synthesis duration and pH value, but also by the acid added to the reaction mixture (nitric or sulphuric). In particular, the presence of sulfuric acid apparently results in α-MnO2 stabilization. It is noted that the type of the acid used in the course of the synthesis, as well as other synthesis conditions exercise no significant influence neither on the shape nor on the size of α-, γ- and δ-MnO2 particles. In contrast, the morphology of β-MnO2 turned out to be extremely sensitive to the synthesis conditions. Long (24 h) hydrothermal processing of reaction mixtures at рН 0.5-1 results in the formation of single-phase pyrolusite. The microstructure of the latter is determined by the reaction mixture composition.


64-71 388
With the goal of searching effective methods of industrial wastes recycling, filler systems for bituminous binders in road building have been proposed. For the first time in the world, the product of recycled tire rubbers, which is an active powder of discretely devulcanized type of rubber in addition to waste of sulfur produced in technological processes of oil refining, natural gas, etc., have been tested in order to improve the quality of bitumen binders. The rheological properties and fatigue life of the sulfur-bitumen binder have been investigated according to the linear amplitude sweep test (LAS) by using a Smart Pave dynamic shear rheometer (Physica MCR series, Anton Paar, Austria). A technique for preparing samples of sulfur-containing binders has been developed based on the results of photomicrographs analysis obtained by optical microscopy. It has been done to study their fatigue cracking resistance. The analysis of the influence of sulfur and elastic filler on fatigue life has showed that the rise of the quantity of cycles up to fatigue damage of binder samples by the factor of 3-5 (strain of 5% and 2.5%) is due to crumb rubber concentration. The addition of sulfur to ternary systems bitumen/sulfur/elastic filler enables saving energy resources as a result of the possibility of manufacturing sulfur-extended asphalt at lower temperatures.


72-80 554
The article considers fipronil determination by the method of RP HPLC in isocratic mode with ultraviolet detection at 280 nm. The analysis of insecticidal gels containing fipronil and fipronil mixture with chlorpyriphos was carried out. The possibility and expediency of determining the isomeric composition of fipronil were considered. The conditions for carrying out extraction of insecticides from gel matrices containing food attractive, including additional processing by ultrasound, were determined. The developed mode of extraction of active ingredients (fipronil and chlorpyriphos) is based on the preferred homogenization of the gel sample with a minimum amount of water followed by extraction with isopropanol acidified with acetic acid. The proposed scheme differs from the previously realized chloroform extraction by the stage of sample preparation. However, under these conditions in case of the gel matrix it is possible to achieve a high degree of homogeneity of the sample and to prevent possible hydrolysis of the target components. At the same time, the selected conditions are well combined with the polarity of the mobile phase upon direct separation. Selected chromatography modes allow identifying the title compound in real insecticides without overlapping signals from other extractable components using the trivial stationary phases. The possibility and expediency of carrying out chromatographic analysis to determine the optical isomers of the title compounds with different insecticidal activity have been considered. The optimal concentration range of fipronil determination in the working solution is from 0.005 to 0.15 mg/ml (chlorpyriphos, from 0.002 to 0.15 mg/ml). The limit of determination of substance in the working solution/swabs is 0.0005 mg/ml.


81-90 415
Practically important problems of non-stationary heat conduction for hyperbolic transport models are considered. An analytical approach based on contour integration of operational solutions of hyperbolic models is developed. This leads to new integral relationships convenient for numerical experiments. The equivalence of new functional constructions and known analytical solutions of this class of problems is shown. On the basis of the obtained relations, the wave character of the nonstationary thermal conductivity is described taking into account the finite velocity of heat propagation. The jumps at the front of the heat wave are calculated. The proposed approach gives effective results when studying the thermal reaction to heating or cooling regions bounded from within by a flat surface, either a cylindrical cavity or a spherical surface.
91-99 406
The article considers the application of the system approach for constructing informational support for the life cycle of the production of medicinal products. The principal difficulties of creating a single informational system of the entire life cycle are considered in this article. A brief analysis of the information and computer support of individual links in the life cycle is given. Particular attention is paid to the use of a systematic approach to the creation of information support for the pharmaceutical development of medicines. The principle of QbD - “Quality planned for development” - was taken as a basis. For the implementation the QbD principle on the basis of the system approach, it is proposed to use the Shewhart-Deming iteration cycle to create an information support for a sustainable search for the optimal version (the program) of the conducted studies. The possibility of combining the PDCA cycle and the methodology of the system approach is shown. On its basis, system-theoretic multiple models of nformation support for pharmaceutical development in the graphic-analytical nomination were constructed. The method of applying the criterial approach for the formation of global and local criteria for managing research and the construction of system management models in the Melentiev’s brackets nomination are presented. The information modeling of the stage of pharmaceutical development has been carried out. Functional models have been constructed in the IDEF0 nomination.

ISSN 2410-6593 (Print)
ISSN 2686-7575 (Online)