Two known iron(iii) complexes, [Fe(H2O)3(L1)]·xH2O (x = 4 (1), 5 (2)) and [Fe(H2O)3(L2)]·3H2O (3), bearing the basic forms of 5-chloro-3-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene)hydrazinyl)-2-hydroxybenzenesulfonic acid (H3L1) and 3-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)-2-hydroxy-5-nitrobenzenesulfonic acid (H3L2), were prepared and used as homogeneous catalysts for cyanosilylation of a variety of aldehydes with trimethylsilyl cyanide leading to the corresponding cyanohydrin trimethylsilyl ethers. High yield (up to 98 %) was observed in the reaction catalyzed by 3 at room temperature in methanol.

It is hard to overestimate the value of honey since the constituent substances in it are of great importance in the food industry and medicine. The quality of honey is established by the legislation of the Russian Federation (GOST). But the levels of these standards are regulated by outdated methods of analysis, which can not give reliable results. The detection of antibiotic residues in honey is a central issue in the quality and safety control of this product. Accumulation of drugs in honey used to treat bee colonies can cause allergies and dysbiosis in people who have eaten such honey, as well as develop antibiotic resistance in microorganisms. At present, one of the promising directions in the field of detecting medicines in honey is the use of high-performance liquid chromatography (HPLC). It helps selectively and accurately detect antibiotic substances in honey bee products. In Russia, the HPLC method is used with mass spectrometry to detect tetracycline residues in honey. A significant drawback with this method that limits the widespread use of it is the application of expensive, technically sophisticated equipment that needs high-quality reagents and consumables. The purpose of this work was to develop the simultaneous identification of tetracycline antibiotics in honey and carry out their quantitative analysis by a reversed-phase HPLC method. A sample preparation algorithm was developed, and the conditions for chromatographing combined indication of tetracyclines in honey at an acceptable concentration according to the MRL (0.01 mg/kg) with Agilent 1260 Infiniti liquid chromatograph equipped with a column thermostat, a gradient pump, and a UV detector were selected. According to the results of the research, the most optimal condition for the simultaneous analysis of oxytetracycline, tetracycline hydrochloride, chlortetracycline in honey by HPLC method with ultraviolet detection was a wavelength of 254 nm, a flow rate of 0.5 ml/min and a column temperature of 25° C. Under these conditions, the antibiotic retention time was determined: 4.069 minutes for oxytetracycline, 4.331 minutes for tetracycline hydrochloride, 4.642 minutes for chlortetracycline. The developed HPLC method for the simultaneous determination of tetracycline antibiotics in honey was tested on honey bee products from the regions of the Republics of Tatarstan and Bashkortostan.

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The kinetics of homogeneous dehydrogenation of formic acid in the presence of supramolecular rhodium(III) complex with P-functionalized calix [4]resorcine were studied in dioxane, tetrahydrofuran, dimethylformamide, and binary formamide-dioxane mixtures (volume ratio 10 : 90, 20 : 80, 30 : 70) over a wide temperature range (40-90°C). The examined Rh(III) complex catalyzed the dehydrogenation process, and its catalytic activity was higher than that observed previously for rhodium complexes with non-macrocyclic phosphorus-containing ligands. The dehydrogenation rate constants were proportional to neither catalyst concentration nor dielectric constant of the medium, which is likely to be related to supramolecular nature of the Rh(III) complex. No micelle formation was observed in the examined systems.In recent time new eco-friendly technologies capable of competing with natural catalytic systems have been developed. Potentially interesting are threedimensional receptors based on calixresorcinarene scaffold, whose functionalization could give rise to catalytically active structures. For example, it is known [1, 2] that aminomethylated calix[4]resorcines catalyze hydrolysis of phosphorus acid esters.Donor groups fixed at the upper or lower rim of a calix[4]resorcine can be involved in both inner-and outer-sphere coordination to metal ions. Such metal complex systems also exhibit catalytic activity in some processes [3]. These systems are obtained with the use of platinum metal compounds, in particular rhodium compounds, and their selectivity is com-parable with that of natural catalysts [4]. Rhodium(I) and rhodium(III) complexes with organo-phosphorus ligands are known [5-7] to catalyze homogeneous dehydrogenation of formic acid under atmospheric pressure at a temperature about 50°C. We previously synthesized complex I, octachloridotetra-23-dodecaene)}tetrarhodium(III) [8] from P(III)-functionalized calix[4]resorcine and triaqua trichloro rhodium complex. In the further treatment, compound I will be referred to as a structural unit with the composition L·4 [Rh +3 (O 2 -)(Cl -) 2 ], where L is P(III)-functionalized calix[4]resorcine. The present article reports on the results of our study on the kinetics of homogeneous dehydrogenation of formic acid in the presence of complex I and its catalytic activity as compared to rhodium complexes studied previously [5,6]. Study on catalytic activity in this reaction is important from the viewpoint of understanding mechanisms of catalytic hydrogen liberation processes [5,[9][10][11][12].Catalytic activity of highly organized systems based on calix[4]resorcines often depends on the type and properties of aggregates formed therein [1,2]. Therefore, we also examined self-aggregation (self-association) of compound I in binary solvent consisting of formamide and dioxane in the range of concentrations c I from 1 × 10 -4 to 5 × 10 -4 M in the presence and in the absence of formic acid. It is known [13,14] that formamide is a strongly solvating solvent toward formic acid. By analogy with...

In this article, we present the first case report of a chicken mycosis caused by F. proliferatum occurred on a private farm in the Russian Federation. Lesions on the skin of the legs and scallops were reported. The object of this study was samples of feed and pathological material from sick hens-layers. Mycological analysis included determination of the total number of fungi (TNF) and identification and determination of the toxicity and pathogenicity of the isolates. The identification of the isolate was carried out taking into account direct microscopy, morphological features, and the method of molecular genetic analysis. Microscopic fungi of the genus Penicillium and Rhizopus were isolated by mycological analysis of the feed. The test feed was nontoxic. Mycological examination of pathological material (scrapings from the combs and affected legs) identified an isolate of Fusarium proliferatum, which showed toxicity on biological objects (protozoa, rabbits) and pathogenicity (white mice). Dermal application of F. proliferatum suspension was accompanied by reddening of the rabbit skin. Intraperitoneal injection of fungal spores caused mycosis in white mice. Polymerase chain reaction (PCR) made it possible to identify this type of microscopic fungus (F. proliferatum) with high accuracy in the samples under study. The research results allow us to consider F. proliferatum as a cause of poultry disease against the background of predisposing factors in the form of desquamation of the stratum corneum of the skin against the background of immunosuppression and metabolic disorders caused by an imbalance in the diet.