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Stanislav A. Grabovskiy

Stanislav A. Grabovskiy
Ufa Institute of Chemistry of the Russian Academy of Sciences

PhD

About

72
Publications
13,134
Reads
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289
Citations
Additional affiliations
January 2015 - present
Russian Academy of Sciences
Position
  • Fellow
March 2003 - July 2003
Italian National Research Council
Position
  • Visiting scientist
Description
  • Research Subject: Theoretical studies on the reaction of sugar radicals with thiols
May 2001 - July 2001
Italian National Research Council
Position
  • Visiting scientist
Description
  • Research Subject: Reactivity of organosilanes in free radical reactions

Publications

Publications (72)
Article
Background 1,1-Bishydroperoxides are used as oxidizing agents, radical initiators, in addition, studies of biological activity show the promise of this area of research. Objective There are currently no kinetic data on the thermal stability of these peroxides in various solvents. Therefore, we investigated the thermal stability of 1,1-dihydroperox...
Article
Full-text available
Context: Previously, we investigated the relationship between the nature of the substituent at the 5-position of the uracil ring and the action of the corresponding uracil derivatives on immortalized lung cells. In the present study, we analyzed the impact of some 6-substituted uracil-derivatives on the regeneration potential of the lung cells (LC)...
Article
The antioxidant effect of a mixture of 3-butyl-5-amino-6-methyluracil and butylated hydroxytoluene (BHT) was studied in a model system of initiated radical chain oxidation of styrene in chlorobenzene at 310 K. The maximum synergistic effect was observed at a ratio of ~0.75 between uracil derivative and BHT concentrations. The mechanism of synergist...
Article
The reactivity of 5‐aminouracil derivatives in the model reaction of autoxidation of styrene initiated by 2,2′‐azobis(2‐methylpropionitrile) was studied. Alkyl substituents at the 6‐position of the uracil ring have a significant effect on the kinetic parameters of inhibition. The N‐H bond dissociation energy calculated at the M06‐2X/MG3S and G4 lev...
Article
The yield of singlet oxygen (¹O2) due to the degradation of triethylsilane, dimethylphenylsilane, triphenylsilane, and dimethyl(trimethylsiloxy)silane hydrotrioxides has been determined for the first time using the IR chemiluminescence technique. The most effective sources of singlet oxygen in this series are triphenylsilyl hydrotrioxide and dimeth...
Article
Complex formation of 2,3-dimethyl-5-hydroxy-6-aminopyrimidine-4(3H)-one with copper(II) ions in nonaqueous solutions has been studied by means of electron, NMR, and IR spectroscopy as well as mass spectrometry. Sequential formation of tetra- and pentacoordinated copper(II) complexes with mono- and bidentate ligand coordination has been observed. Th...
Article
Palladium(II) chloro complex with {[6-amino-2-(butylsulfanyl)pyrimidin-4-yl]oxy}acetic acid has been synthesized via the ligand substitution method. Composition and structure of the coordination compound have been elucidated from the combined data of elemental analysis and spectroscopy. The coordination of {[6-amino-2-(butylsulfanyl)pyrimidin-4-yl]...
Article
Decomposition of benzoyl peroxide in the presence of ferrocene has been shown to proceed simultaneously via several pathways—thermal decomposition, the decomposition catalyzed by iron ions, and the reaction with ferrocene with the formation of ferrocenium radical-cation.
Article
6-Amino-5-hydroxy-2,3-dimethylpyrimidin-4(3H)-one inhibits initiated styrene oxidation with the same efficiency as vitamin E compounds. Calculations at M05/MG3S level of theory for the abstraction of a hydrogen atom by a peroxyl radical indicate an early transition state, which closely resembles a pre-reaction hydrogen bond-containing complex respo...
Article
The review summarizes data on pro- and antioxidant properties of uracil derivatives comprising an important group of pharmacologically active compounds. The presence of OH or NH2 groups at position 5 of the uracil ring was shown to be essential for these compounds to have both antioxidant and prooxidant properties. The mechanism of pro- and antioxi...
Article
The catalytic hydroxylation of 2,3-dimethyl-5-hydroxy-6-aminopyrimidine-4(3H)-one in an aqueous solution in the presence of copper(II) ions and oxygen proceeds with the formation of 2,3-dimethyl-5,5,6-trihydroxy-6-aminopyrimidine-4-(3H)-one.
Article
Aim and objective: Some ferrocenyl derivatives are active in vitro and in vivo against cancer. Generally, ferrocenyl derivatives for cancer research have three key components: a ferrocene moiety, a conjugated linker that lowers the oxidation potential and some derivative (peptide, nucleobase and others) that can interact with biomolecules. Since t...
Article
The yield of singlet oxygen (¹О2) in the decomposition of a number of hydrotrioxides of alcohols (cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, L-menthol, 1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol, 1,3,3-trimethylbicyclo[2.2.1]heptan-2-ol, heptan-4-ol, propanol-2, and 1-cyclopropylethanol) has been determined using the IR c...
Patent
Full-text available
FIELD: medicine. SUBSTANCE: invention relates to medicine, in particular to pharmacology. Proposed pharmaceutical composition comprising 1,3-dimethyl-5-carboxyuracyl and glycyrrhizinic acid in a molar ratio of components 1,3-dimethyl-5-carboxyuracyl:glycyrrhizinic acid, equal to 1:2, with a pronounced stimulating effect on reparative regeneration o...
Article
Background: Pyrimidine-based drugs stimulate tissue regeneration and immunity, two components that need to be improved in a number of respiratory diseases of different etiology (e.g. influenza and asthma). In the present study we investigated relationships between the character of substitutions in the uracil structure and the impact of the respecti...
Article
5-Aminouracil was found to form a six-coordinate copper(II) complex in aqueous solution and undergo oxidation to 5,5,6-trihydroxypyrimidine-2,4(1H,3H)-dione in the presence of molecular oxygen. A scheme was proposed for the fixation and activation of molecular oxygen on six-coordinate copper(II) complex with 5-aminouracil. The effect of the ligand...
Article
The fixation and activation of molecular oxygen on copper(II) complexes with 5-hydroxy and 5-aminoorotic acids, leading to oxidation of the ligand.
Article
cis-Dihalogeno complexes of platinum(II) and palladium(II) with 6-tert-butyl-2-thiouracil have been synthesized. The mode of coordination of the ligand to metal ions was established by IR and NMR spectroscopy.
Article
Background: Many synthetic and natural uracil derivatives have biological activity. Furthermore, many of these derivatives have pro- and antioxidant properties, but the mechanism of these processes is far from being understood. Methods: Oxygen-uptake kinetics and computational methods (CBS-QB3, M062X/MG3S and SMDM05/ MG3S) were combined to study th...
Article
Cyclic hydrotrioxides were synthesized by low-temperature (-78 A degrees C) ozonolysis of a series of cyclic alcohols and identified using H-1 NMR spectra. The kinetic regularities of the thermal decomposition of the synthesized hydrotrioxides were studied. The experimental proof of the induced decomposition of alcohol hydrotrioxides was obtained f...
Article
The processes of protonation of 5-aminouracil, 5-amino-1,3,6-trimethyluracil, and 6-aminouracil in aqueous solutions were studied by UV and ¹³С NMR spectroscopy in combination with quantum-chemical calculations.
Article
Palladium catalysts supported on a carbon–silica material were synthesized. Hydrogenation by molecular hydrogen was studied in the presence of straight-chain and cyclic olefins. As distinct from what is observed for olefins having a phenyl substituent, for aliphatic alkenes the reaction rate decreases with an increasing conversion due to the accumu...
Article
Low-temperature ozone oxidation of a series of saturated carbocyclic hydrocarbons afforded the corresponding alcohols and/or ketones in high yield through intermediate trioxidanes. exo,endo-Tetracyclo-[6.2.1.03,5]undecane-2,7-dione and exo,endo,endo-hexacyclo[9.3.1.03,8.04,6.05,9.012,14]pentadecane-2,10-dione were isolated, and exo,endo,exo-pentacy...
Article
Complex formation between 5-aminoorotic acid and copper(II) ions in DMSO solution has been studied by means of electron absorption, NMR, and IR spectroscopy. The complex composition and its formation constant have been determined by means of spectrophotometry. NMR and IR spectroscopy data have revealed the donor sites of 5-aminoorotic acid involved...
Article
The interaction of diacylated ethylenediamine with aqueous solutions of hydrochloric acid (1.0 - 12.4 mol L-1) was studied. IR spectroscopy and 1H and 13C NMR spectroscopy revealed that the amide groups of the reagent are not protonated in the whole range of HCl concentrations. At relatively high concentrations of hydrochloric phase in the aqueous...
Article
Participation of molecular oxygen in the reaction of ferrocene with benzoyl peroxide in various solvents is demonstrated. The stoichiometry of the reaction ferrocene: oxygen is determined at 2: 1. Based on NMR, IR spectroscopy, iodometry, and elemental analysis of the product the formation of [μ-(peroxy-O:O′)]-diferrocenium benzoate is suggested.
Article
By a single crystal X-ray diffraction study the molecular structure of 3,7-dimethyl-9-thia-3,7-diazabicyclo[3.3.1]nonane-9,9-dioxide having a chair-chair conformation with a diequatorial arrangement of methyl groups at nitrogen atoms is determined. Compound 1 C8H16N2O2S crystallizes in the space group Pnma with the following cell parameters: a = 11...
Article
The role of the ferrocenium radical cation and Cp2Fe+–O radical in the initiation of methyl methacrylate polymerization in the absence and presence of oxygen was demonstrated.
Article
This review deal with the reactivity of 5-substituted uracil derivatives toward peroxyl radicals. These compounds should play an important role in biological systems and have considerable attention in pharmacology. Comparative evaluation of reactivity is carried out, as well as methodologies studies for the reactivity of uracil derivatives toward p...
Article
Dehydration of 5,6-dihydro-5,6-dihydroxy-6-methyl- and 5,6-dihydro-5,6-dihydroxy-1,3,6-trimethyl-uracil in 0.4 M aqueous sulfuric acid gives 5-hydroxy-6-methyl- and 5-hydroxy-1,3,6-trimethyluracil in quantitative yields. Two possible mechanisms have been examined using the mPW1k/6-311+G(2df,2pd)//mPW1k/6-31+G(d,p) method for the transformation of m...
Article
The products and kinetics of the thermal decomposition of dimethyldioxirane (DMDO) were studied. The reaction proceedsvia three parallel pathways: isomerization to methyl acetate, oxygen atom insertion into the C−H bond of a solvent molecule (acetone), and the solvent-induced homolysis of the O−O bond in the DMDO molecule. The contribution of the l...
Article
Complex formation of 5-hydroxyorotic acid with copper(II) chloride in water solution is studied by electron spectroscopy. The composition of the complex was established spectrophotometrically by molar ratio method and confirmed by elemental analysis. The constant of complex formation was calculated. By the IR spectroscopy the electron-donating cent...
Article
The reaction of 5-aminouracil with peroxyl radicals generated by the thermal decomposition of 2,2'-azo-bis(2- methylpropionitrile) (AIBN) and 2,2'-azo-bis(2-amidinopropane) dihydrochloride was studied at 50°C in ethanol and water (pH 7.0) solution respectively. The oxidation product of 5-aminouracil formed by peroxyl radicals was dihydro-5,5,6-trih...
Article
Eicosapentaenoic acid (EPA) is a polyunsaturated fatty acid present in fish oils used for omega-3 enriched diets. The natural cis double bond geometry can be transformed to the trans configuration during the deodorization process utilized in the food industry. The analytical discrimination of the possible five monotrans regioisomers represents a li...
Article
Oxidation of 5-hydroxy-6-methyluracil with molecular oxygen in the presence of copper(II) chloride involves formation of a 2 : 1 complex with copper(II). The rates of consumption of initial 5-hydroxy-6-methyluracil and oxygen were determined in the temperature range from 40 to 80°C. A probable reaction mechanism implies fixation and activation of m...
Article
The field of artificial enzymes is rapidly evolving subject.As the barrier between chemistry and biology becomes less distinct a range of new methods, which combine expertise from both areas, are developing.In recognition of both the fact that the de novo design approach can be time consuming, and that a tiny miscalculation will have a detrimental...
Article
The action of oxidants is one most popular methods for the functionalization ofcompounds belonging to different classes. From this point of view, chlorine dioxide is ofgreat interest. Chlorine dioxide is large-tonnage industrial reagent. It has been used forodor control and desinfection in water preparation. The most part of works on thechemistry o...
Article
Addition of millimolar amounts of a weak base (pyridines) dramatically accelerates the reaction with peroxyl radicals of two biologically relevant uracil derivatives, 5-hydroxyuracil (HU) and 5-hydroxy-6-methyluracil (HMU). This is due to the formation of small amounts of the deprotonated form (pK(a) = 8.1-8.5 in water), which reacts with peroxyl r...
Article
The separation of cis and trans isomers is relevant for biological and nutritional applications, silver-exchanged zeolite Y was prepared and applied for the treatment of mixtures of cis and trans geometrical isomers of mono- and polyunsaturated fatty acid methyl esters (FAMEs). cis FAMEs were adsorbed into zeolite with a high degree of selectivity...
Article
The reactivity of 5-hydroxy-6-methyluracil (HMU) towards peroxyl radicals generated from the aerobic thermal decomposition of 2,2'-azo-bis(2-amidinopropane)dihydrochloride (AAPH) has been investigated. The oxidation product of HMU is dihydro-5,5,6-trihydroxy-6-methylpyrimidin-2,4-dion-e (94%). The relative oxidation rate of HMU vs. quercetin by per...
Article
The reactivity of 5-hydroxy-6-methyluracil (HMU) towards peroxyl radicals generated from the aerobic thermal decomposition of 2,2′-azo-bis(2-amidinopropane)dihydrochloride (AAPH) has been investigated. The oxidation product of HMU is dihydro-5,5,6-trihydroxy-6-methylpyrimidin-2,4-dion-e (94%). The relative oxidation rate of HMU vs. quercetin by per...
Article
The products and kinetics of the thermolysis of 1,2-dioxaspiro[2,5]octane in cyclohexanone and cyclohexanone-CCl4 mixtures are studied. 1,2-Dioxaspiro[2,5]octane is consumed via two parallel routes: isomerization to oxepan-2-one and solvent (cyclohexanone) oxidation with the partial escape of radicals from the cage (17% at 25 °C). Under an inert at...
Article
The kinetics of oxidation of a series of alcohols (propan-2-ol, 2-methylpropan-1-ol, butan-1-ol, butan-2-ol, 3-methylpentan-1-ol, heptan-4-ol, decan-2-ol, cyclohexanol, borneol) by chlorine dioxide in organic solvents was studied using spectrophotometry. The reaction is described by the second-order rate equation W = k[ROH][ClO2]. The rate constant...
Article
The product of the reaction of valeraldehyde with chlorine dioxide was determined, and the solvent effect on the reaction kinetics was studied. The major oxidation product is valeric acid. The reaction rate is described by the second-order equation w = k[RCHO]·[ClO2]. The rate constants were measured in the 297–328 K interval, and the activation pa...
Article
The reaction of 5-hydroxy-6-methyluracil with peroxy radicals generated by the thermal decomposition of azodiisobutyronitrile was studied at 75 °C in ethanol, propan-2-ol, and dimethyl sulfoxide. The stoichiometry of the reaction is 1: 1. The reaction product is dihydro-6-hydroxy-6-methylpyrimidine-2,4,5-trione in an anhydrous solvent or dihydro-5,...
Article
The kinetic features and products of the thermolysis of 2-[4-(chloro-tert-butyl)phenyl]propan-2-yl hydroperoxide in the temperature range 120–190�C have been studied. The mechanism of the process is discussed.
Article
Dimethyl- (DMD) and methyl(trifluoromethyl)-dioxiranes were used for oxyfunctionalization of spiro{1',7-cyclopropan-(E)-2-methylbicyclo[2.2.1]heptane}, tricyclo[3.2.2.0(2,4)]nonane, exo-endo-endo- and exo-exo-exo-heptacyclo[9.3.1.0(2,10).0(3,8).0(4,6).0(5,9).0(12,14)]pentadecane, yielding tertiary alcohols as the main products. The rate constants f...
Article
Low-temperature (−70 °C) ozonization of exo-bicyclo[2.2.1]heptan-2-ol in CCl3F led to a hydrotrioxide, which was identified by 1H NMR spectroscopy. Kinetics of decomposition of given hydrotrioxide was studied by analysis of the chemiluminescence fading in the IR range of the spectrum and the activation parameters of the process were calculated. Sin...
Article
The use of dimethyldioxirane (DMD) as the epoxidizing agent for polyunsaturated fatty acids was investigated. With fatty acid methyl esters, this is a convenient method for avoiding acidic conditions, using different solvents, and simplifying the isolation procedures, with less contamination due to by-products. The reagent was also tested with free...
Article
The products and kinetic regularities of thermal decomposition of ethyl(methyl)dioxirane (EMD) were studied. The consumption of EMD occurs via four parallel pathways: two isomerizations to ethyl acetate and methyl propionate, solvent oxidation via insertion of the oxygen atom into the C-H bond of a solvent molecule (butanone), and hydrogen atom abs...
Article
Oxidation of a series of tert-butyl ethers ButOR (R = Me, Et, CH2CH2Cl, Pri, Bui), diethyl ether, diisopropyl ether, 1,2-dimethoxyethane, diisobutoxymethane, 1,4-dioxane, and tetrahydrofuran with dimethyldioxirane (DMDO) was studied. The reaction kinetics obeys the second-order equation w = k[DMDO][ether]. The rate constants in a range of 5–50 °C a...
Article
The products and the kinetics of the reaction of dimethyldioxirane with adamantane in CCl4 were studied. It was found that the reaction simultaneously occurred via molecular and radical paths. The contribution of the radical process was 65% at 30.6°C. The activation parameters of the reaction of dimethyldioxirane with adamantane in the presence of...
Article
The kinetics of the reaction of dimethyldioxirane with fullerene C-60 was studied, and the activation parameters logk = (8.3+/-0.8) - (14.2+/-0.9)/theta, (theta = 2.3RT kcal mol(-1)) (20-45 degreesC) were determined. The formation of paramagnetic particles was detected.
Article
The oxidation of a variety of triorganosilanes by dimethyldioxirane afforded the corresponding silanols in quantitative yield. The reactions are performed at room temperature using acetone or CCl4 as the solvent. Under similar conditions, (Me3Si)3SiH gave silanol in 80−90% yield together with other identified products. Rate constants for these reac...
Article
Oxidation of aromatic amine hydrohalides (aniline hydrochloride, hydrochloride, and hydrofluoride; 4-methylaniline hydrochloride and hydrobromide; 3-methylaniline and N,N-diethylaniline hydrochlorides) with dimethyldioxirane was studied. The product composition was analyzed in relation to the reactant ratio.
Article
The kinetics of oxidation of a series of monoatomic alcohols (methanol, 2-propanol, 2-butanol, 2-methyl-1-propanol, 2-chloroethanol, 1,3-dichloro-2-propanol, benzyl alcohol), hydroxyacetic acid, and 1,3-butandiol (ROH) by dimethyldioxirane (1) was studied. The reaction kinetics obeys the second order equationw=k[ROH][1]. The rate constants were mea...
Article
The oxidation of secondary and tertiary amines, derivatives of 2,2,6,6-tetramethylpiperidine and 2,2,5,5-tetramethyl-3-imidazoline-3-oxide, by dimethyldioxirane results in the formation of nitroxyl radicals, which induce the decomposition of dimethyldioxirane. Chemiluminescence in the IR and visible regions during the reaction of dimethyldioxirane...
Article
The relative reactivity of bis-oxyisopropylidene biradical ‘OCMe2O’ generated upon homolysis of the O−O bond of dimethyldioxirane was characterized by the ratio of the rate constants for H atom abstraction and β-cleavage:k 3 /k 2 =0.230.06 L mol−1 (314 K).
Article
Dimethyldioxirane decomposition in oxygen atmosphere follows a first-order kinetic law. Decomposition rate constant (k, s−1) in acetone in the temperature range from 30 to 50°C has been determined as lgk=(7.1±0.9)−(16.0±1.4)/θ, θ=2.303RT kcal/mol.
Article
Dimethyldioxirane consumption increases considerably in the presence of cumene. The product composition (cumic alcohol, acetophenone, α-methylstyrene) and the inhibiting effect of oxygen prove a radical reaction mechanism. The kinetic order for dimethyldioxirane increases with the conversion from 1.5 to 2.

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Project (1)
Project
The effect of drugs from the group of pyrimidine derivatives on post-traumatic regeneration of the skin, peripheral nerves, muscle and bone tissue will be studied in this project. This corresponds to the frame of the selected problems and scientific priorities. So far, there are no universally accepted clinical medicine medications stimulates of posttraumatic tissue regeneration, so the search of effective compounds having such a property, it is an actual problem.