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351 results on '"Stoikov I."'

1. Organic Chemistry in Russian Universities. Achievements of Recent Years

Author

Stoikov, I. I., Antipin, I. S., Burilov, V. A., Kurbangalieva, A. R., Rostovskii, N. V., Pankova, A. S., Balova, I. A., Remizov, Yu. O., Pevzner, L. M., Petrov, M. L., Vasilyev, A. V., Averin, A. D., Beletskaya, I. P., Nenajdenko, V. G., Beloglazkina, E. K., Gromov, S. P., Karlov, S. S., Magdesieva, T. V., Prishchenko, A. A., Popkov, S. V., Terent’ev, A. O., Tsaplin, G. V., Kustova, T. P., Kochetova, L. B., Magdalinova, N. A., Krasnokutskaya, E. A., Nyuchev, A. V., Kuznetsova, Yu. L., Fedorov, A. Yu., Egorova, A. Yu., Grinev, V. S., Sorokin, V. V., Ovchinnikov, K. L., Kofanov, E. R., Kolobov, A. V., Rusinov, V. L., Zyryanov, G. V., Nosov, E. V., Bakulev, V. A., Belskaya, N. P., Berezkina, T. V., Obydennov, D. L., Sosnovskikh, V. Ya., Bakhtin, S. G., Baranova, O. V., Doroshkevich, V. S., Raskildina, G. Z., Sultanova, R. M., Zlotskii, S. S., Dyachenko, V. D., Dyachenko, I. V., Fisyuk, A. S., Konshin, V. V., Dotsenko, V. V., Ivleva, E. A., Reznikov, A. N., Klimochkin, Yu. N., Aksenov, D. A., Aksenov, N. A., Aksenov, A. V., Burmistrov, V. V., Butov, G. M., Novakov, I. A., Shikhaliev, Kh. S., Stolpovskaya, N. V., Medvedev, S. M., Kandalintseva, N. V., Prosenko, O. I., Menshchikova, E. B., Golovanov, A. A., and Khashirova, S. Yu.

Published
2024
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14. An Acetylcholinesterase Sensor Based on a Pillar[6]arene-Silver Nanoparticle Composite for the Determination of Drugs for the Treatment of Alzheimer's Disease

Author

Shamagsumova, R. V., Vasyk, A. V., Shurpik, D. N., Evtugin, V. G., Stoikov, I. I., and Evtugin, G. A.

Subjects
Alzheimer's disease -- Drug therapy, Silver, Detectors, Enzyme inhibitors, Enzymes, Chemistry
Abstract

We developed a voltammetric sensor based on a glassy carbon electrode modified with carbon black, pillar[6]arene, and silver nanoparticles for the determination of reversible acetylcholinesterase inhibitors used in the treating of Alzheimer's and other neurodegenerative diseases. Silver nanoparticles formed directly in the layer by reducing silver ions with hydroquinone fragments of the macrocycle. Their formation was confirmed by transmission electron microscopy. The enzyme was immobilized over the modifying layer using carbodiimide binding. The electrochemical properties of the coating components were revealed. A dependence of the oxidation peak currents of the macrocycle and silver nanoparticles on the method of the formation of the surface layer was found. The current of the pillararene oxidation peak changed upon the addition of acetylthiocholine because of its involvement in the oxidation of the product of the enzymatic hydrolysis of the substrate. Donepezil, huperzine A, berberine, and galantamine reduced the rate of enzymatic reaction. The change in the oxidation current, measured in the chronoamperometry mode, depended on the concentration of the inhibitor. The calibration dependence for the determination of inhibitors had a sigmoid character and was approximated by a logistic function. The limits of detection, estimated by the concentration corresponding to 15% inhibition, were 1.2 nM for huperzine A, 12.5 nM for galantamine, 2.5 nM of donepezil, and 10 nM for berberine. The developed biosensor was tested in determining residual galantamine in artificial urine., Author(s): R. V. Shamagsumova [sup.1], A. V. Vasyk [sup.1], D. N. Shurpik [sup.1], V. G. Evtugin [sup.1], I. I. Stoikov [sup.1], G. A. Evtugin [sup.1] Author Affiliations: (1) grid.77268.3c, 0000 [...]

Published
2022
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15. Polyelectrolyte Polyethylenimine-DNA Complexes in the Composition of Voltammetric Sensors for Detecting DNA Damage

Author

Malanina, A. N., Kuzin, Yu. I., Ivanov, A. N., Ziyatdinova, G. K., Shurpik, D. N., Stoikov, I. I., and Evtugyn, G. A.

Subjects
Methylene blue, Polyelectrolytes, DNA, Sensors, DNA damage, Permeability, Chemistry
Abstract

A voltammetric DNA sensor based on the polyelectrolyte complexes of polyethylenimine and DNA obtained by self-assembly from solutions of components on a glassy carbon electrode has been developed. Cyclic voltammetry was used to study the preparation conditions and characterize the permeability of the complex for low-molecular-weight redox indicators differing in the mechanism of interaction with DNA (methylene blue and methylene green). The formation of the polyelectrolyte complex was independently confirmed by surface plasmon resonance measurements. The redox peak currents of methylene blue and methylene green varied differently depending on the number of layers of the complex and the nature of the outer layer due to different mechanisms of binding the indicators to DNA molecules and varied assembly density of the complex polyelectrolytes. An increase in the concentration of polyions from 0.1 to 10 [mu]g/mL suppressed the effect of the charge of the outer layer on the indicator currents. Polyelectrolyte coatings were tested to detect specific DNA interactions including intercalation with the anticancer drug doxorubicin and the thermal and chemical denaturation of DNA. It was found that the introduction of decacarboxylated pillar[5]arene into the layer increased the sensitivity of the methylene blue signal to the thermal denaturation of DNA. A comparison between changes in the peak currents of methylene blue and methylene green makes it possible to distinguish the mechanism of DNA damage and separately take into account the contribution of the considered chemical and physical damaging factors. The developed DNA sensor makes it possible to semiquantitatively evaluate the protective effect of antioxidants, which decrease the effect of reactive oxygen species on DNA in the biosensor., Author(s): A. N. Malanina [sup.1], Yu. I. Kuzin [sup.1], A. N. Ivanov [sup.1], G. K. Ziyatdinova [sup.1], D. N. Shurpik [sup.1], I. I. Stoikov [sup.1], G. A. Evtugyn [sup.1] Author [...]

Published
2022
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29. Modern Trends of Organic Chemistry in Russian Universities

Author

Konovalov, A. I., Antipin, I. S., Burilov, V. A., Madzhidov, T. I., Kurbangalieva, A. R., Nemtarev, A. V., Solovieva, S. E., Stoikov, I. I., Mamedov, V. A., Zakharova, L. Ya., Gavrilova, E. L., Sinyashin, O. G., Balova, I. A., Vasilyev, A. V., Zenkevich, I. G., Krasavin, M. Yu., Kuznetsov, M. A., Molchanov, A. P., Novikov, M. S., Nikolaev, V. A., Rodina, L. L., Khlebnikov, A. F., Beletskaya, I. P., Vatsadze, S. Z., Gromov, S. P., Zyk, N. V., Lebedev, A. T., Lemenovskii, D. A., Petrosyan, V. S., Nenaidenko, V. G., Negrebetskii, V. V., Baukov, Yu. I., Shmigol’, T. A., Korlyukov, A. A., Tikhomirov, A. S., Shchekotikhin, A. E., Traven’, V. F., Voskresenskii, L. G., Zubkov, F. I., Golubchikov, O. A., Semeikin, A. S., Berezin, D. B., Stuzhin, P. A., Filimonov, V. D., Krasnokutskaya, E. A., Fedorov, A. Yu., Nyuchev, A. V., Orlov, V. Yu., Begunov, R. S., Rusakov, A. I., Kolobov, A. V., Kofanov, E. R., Fedotova, O. V., Egorova, A. Yu., Charushin, V. N., Chupakhin, O. N., Klimochkin, Yu. N., Osyanin, V. A., Reznikov, A. N., Fisyuk, A. S., Sagitullina, G. P., Aksenov, A. V., Aksenov, N. A., Grachev, M. K., Maslennikova, V. I., Koroteev, M. P., Brel’, A. K., Lisina, S. V., Medvedeva, S. M., Shikhaliev, Kh. S., Suboch, G. A., Tovbis, M. S., Mironovich, L. M., Ivanov, S. M., Kurbatov, S. V., Kletskii, M. E., Burov, O. N., Kobrakov, K. I., and Kuznetsov, D. N.

Published
2018
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31. ТВЕРДОКОНТАКТНЫЕ ПОТЕНЦИОМЕТРИЧЕСКИЕ СЕНСОРЫ НА ОСНОВЕ НАНОЧАСТИЦ СЕРЕБРА В СУПРАМОЛЕКУЛЯРНОЙ МАТРИЦЕ ДЛЯ ОПРЕДЕЛЕНИЯ ГАЛОГЕНИД-ИОНОВ

Author

Sorvin, M. I., Saveliev, A. A., Stoikov, I. I., Belyakova, S. V., Evtugyn, G. A., State assignment in the sphere of scientific activities (grant No 0671-2020-0063), and Государственное задание в сфере научной деятельности № 0671-2020-0063

Subjects
Analytical Chemistry
Abstract

Determination of halogenide ions in pharmaceuticals and various waters is an actual task for the modern analytical chemistry. In the current work, solid-contact potentiometric sensor, based on the glassy carbon electrode covered with the layer of electropolymerized polyaniline and suspension of silver nanoparticles in the matrix of thiacalix[4]arene derivative bearing terminal catechol groups, has been described. The suspension was obtained by the chemical reduction of silver ions with the thiacalix[4]arene and drop casted on the polyaniline layer. The sensor showed potentiometric response to chloride-, bromide and iodide ions. For the simultaneous determination of iodide and bromide ions, a multi-sensor system, consisting of four electrodes with the different volumes of the suspension placed on the polyaniline layer, has been developed. The possibility of the response prediction within the simple additive model was found for the set of the iodide and bromide mixtures. In a similar manner, simultaneous determination of both ions in the variable mixtures has been performed. The multi-sensor system was tested during the determination of iodides in iodine containing pharmaceuticals and the determination of iodide and bromide ions in the artificial mineral water samples. Ionic chromatography was chosen as the comparison method. Sensors made it possible to determine from 0.1 μM to10 mMiodide and bromide ions in mixtures. The proposed approach and solid-contact potentiometric sensors can be used in the analysis of ion content of the waters and in control of the production and storage conditions of pharmaceuticals.Key words: Solid-contact sensor, ionometry, halogenide determination, polyaniline, multisensory system, additive model of the responseDOI: http://dx.doi.org/10.15826/analitika.2022.26.3.002M.I. Sorvin, A.A. Saveliev, I.I. Stoikov, S.V. Belyakova, G.A. Evtugyn Kazan (Volga-Region) federal university, Russian Federation, 420008, Kazan, Kremlevskaya Str. 18, Определение содержания галогенид-ионов в лекарственных препаратах и водах различного назначения представляет собой актуальную задачу современной аналитической химии. В работе представлен твердоконтактный потенциометрический сенсор на основе стеклоуглеродного электрода, покрытого слоем электрополимеризованного анилина и суспензией наночастиц серебра в матрице производного тиакаликс[4]арена с концевыми пирокатехиновыми группами. Суспензию получали, химически восстанавливая ионы серебра тиакаликс[4]ареном и капельно наносили на слой полианилина. Сенсор демонстрировал потенциометрический отклик на хлорид-, бромид и йодид-ионы. Для одновременного определения йодид- и бромид ионов предложено использовать мультисенсорную систему из четырех электродов, отличающихся составом и объемом суспензии, наносимой на полимерную подложку полианилина. На выборке смесей йодид- и бромид-ионов показана возможность предсказания отклика на основе простой аддитивной модели. Аналогичным образом проводили одновременное определение обоих ионов в смесях произвольного состава. Мультисенсорная система была апробирована на определении йодид-ионов в йодсодержащих медицинских препаратов, а также йодид- и бромид-ионов в искусственных образцах минеральной воды. Методом сравнения выступала ионная хроматография. Сенсоры позволяют проводить определение от 0.1 мкМ до10 мМйодид- и бромид-ионов в смесях. Предложенный подход и твердоконтактные потенциометрические сенсоры могут найти применение в анализе ионного состава вод и контроля производства и хранения лекарственных препаратов.Ключевые слова: Твердоконтактный сенсор, ионометрия, определение галогенидов, полианилин, мультисенсорная система, аддитивная модель откликаDOI: http://dx.doi.org/10.15826/analitika.2022.26.3.002

Published
2022

36. Electrochemical DNA Sensor Based on Carbon Black—Poly(methylene blue)—Poly(neutral red) Composite

Author

Kappo, D., Shurpik, D., Padnya, P., Stoikov, I., Rogov, A., Evtugyn, G., Kappo, D., Shurpik, D., Padnya, P., Stoikov, I., Rogov, A., and Evtugyn, G.

Abstract

The detection of small molecules interacting with DNA is important for the assessment of potential hazards related to the application of rather toxic antitumor drugs, and for distinguishing the factors related to thermal and oxidative DNA damage. In this work, a novel electrochemical DNA sensor has been proposed for the determination of antitumor drugs. For DNA sensor assembling, a glassy carbon electrode was modified with carbon black dispersed in DMF. After that, pillar [5]arene was adsorbed and Methylene blue and Neutral red were consecutively electropolymerized onto the carbon black layer. To increase sensitivity of intercalator detection, DNA was first mixed with water-soluble thiacalixarene bearing quaternary ammonium groups in the substituents at the lower rim. The deposition of the mixture on the electropolymerized dyes made it possible to detect doxorubicin as model intercalator by suppression of the redox activity of the polymerization products. The DNA sensor made it possible to determine 0.5 pM–1.0 nM doxorubicin (limit of detection 0.13 pM) with 20 min of incubation. The DNA sensor was successfully tested on spiked samples of human plasma and doxorubicin medication. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

Published
2022

37. Solid-contact potentiometric sensors based on silver nanoparticles in the supramolecular matrix for the determination of halogenide ions

Author

Sorvin, M. I., Saveliev, A. A., Stoikov, I. I., Belyakova, S. V., and Evtugyn, G. A.

Subjects
ADDITIVE MODEL OF THE RESPONSE, POLYANILINE, ОПРЕДЕЛЕНИЕ ГАЛОГЕНИДОВ, ПОЛИАНИЛИН, МУЛЬТИСЕНСОРНАЯ СИСТЕМА, IONOMETRY, HALOGENIDE DETERMINATION, ИОНОМЕТРИЯ, АДДИТИВНАЯ МОДЕЛЬ ОТКЛИКА, ТВЕРДОКОНТАКТНЫЙ СЕНСОР, SOLID-CONTACT SENSOR, MULTISENSORY SYSTEM
Abstract

Определение содержания галогенид-ионов в лекарственных препаратах и водах различного назначения представляет собой актуальную задачу современной аналитической химии. В работе представлен твердоконтактный потенциометрический сенсор на основе стеклоуглеродного электрода, покрытого слоем электрополимеризованного анилина и суспензией наночастиц серебра в матрице производного тиакаликс[4]арена с концевыми пирокатехиновыми группами. Суспензию получали, химически восстанавливая ионы серебра тиакаликс[4]ареном и капельно наносили на слой полианилина. Сенсор демонстрировал потенциометрический отклик на хлорид-, бромид и йодид-ионы. Для одновременного определения йодид- и бромид ионов предложено использовать мультисенсорную систему из четырех электродов, отличающихся составом и объемом суспензии, наносимой на полимерную подложку полианилина. На выборке смесей йодид- и бромид-ионов показана возможность предсказания отклика на основе простой аддитивной модели. Аналогичным образом проводили одновременное определение обоих ионов в смесях произвольного состава. Мультисенсорная система была апробирована на определении йодид-ионов в йодсодержащих медицинских препаратов, а также йодид- и бромид-ионов в искусственных образцах минеральной воды. Методом сравнения выступала ионная хроматография. Сенсоры позволяют проводить определение от 0.1 мкМ до 10 мМ йодид- и бромид-ионов в смесях. Предложенный подход и твердоконтактные потенциометрические сенсоры могут найти применение в анализе ионного состава вод и контроля производства и хранения лекарственных препаратов. Determination of halogenide ions in pharmaceuticals and various waters is an actual task for the modern analytical chemistry. In the current work, solid-contact potentiometric sensor, based on the glassy carbon electrode covered with the layer of electropolymerized polyaniline and suspension of silver nanoparticles in the matrix of thiacalix[4]arene derivative bearing terminal catechol groups, has been described. The suspension was obtained by the chemical reduction of silver ions with the thiacalix[4]arene and drop casted on the polyaniline layer. The sensor showed potentiometric response to chloride-, bromide and iodide ions. For the simultaneous determination of iodide and bromide ions, a multi-sensor system, consisting of four electrodes with the different volumes of the suspension placed on the polyaniline layer, has been developed. The possibility of the response prediction within the simple additive model was found for the set of the iodide and bromide mixtures. In a similar manner, simultaneous determination of both ions in the variable mixtures has been performed. The multi-sensor system was tested during the determination of iodides in iodine containing pharmaceuticals and the determination of iodide and bromide ions in the artificial mineral water samples. Ionic chromatography was chosen as the comparison method. Sensors made it possible to determine from 0.1 μM to10 mMiodide and bromide ions in mixtures. The proposed approach and solid-contact potentiometric sensors can be used in the analysis of ion content of the waters and in control of the production and storage conditions of pharmaceuticals. Работа выполнена за счет средств субсидии, выделенной Казанскому федеральному университету для выполнения государственного задания в сфере научной деятельности № 0671-2020-0063. This work was funded by the subsidy allocated to Kazan Federal University for the state assignment in the sphere of scientific activities (grant No 0671-2020-0063).

Published
2022

43. Diastereoselective intramolecular cyclization/Povarov reaction cascade for the one-pot synthesis of polycyclic quinolines

Author

Kuznetsova, E. A., primary, Smolobochkin, A. V., additional, Rizbayeva, T. S., additional, Gazizov, A. S., additional, Voronina, J. K., additional, Lodochnikova, O. A., additional, Gerasimova, D. P., additional, Dobrynin, A. B., additional, Syakaev, V. V., additional, Shurpik, D. N., additional, Stoikov, I. I., additional, Burilov, A. R., additional, Pudovik, M. A., additional, and Sinyashin, O. G., additional

Published
2022
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46. Metal (Na+, K+, Cs+) Template Effect–Controlled Synthesis of Stereoisomers of Tetrasubstituted (Thia)calix[4]arene Derivatives Containing Sulfonatoalkyl Moieties on the Lower Rim.

Author

Nugmanova, А. R., Yakimova, L. S., Shibaeva, K. S., and Stoikov, I. I.

Subjects
STEREOISOMERS, ALKALI metals, MOIETIES (Chemistry), ALKALI metal ions, METALS, ALKYLATION
Abstract

New water-soluble derivatives of thiacalix[4]arene, p-tert-butylcalix[4]arene, and p-tert-butylthiacalix[4]arene with sulfonatopropyl- and sulfonatobutyl moieties on the lower rim were synthesized. The template effect of alkali metal cations (Na+, K+, Cs+) on the configuration of products formed in the alkylation reaction of lower rim with 1,3-propane- and 1,4-butanesultone was revealed. In the case of Na+, the cone stereoisomer was formed exclusively, while with K+ and Cs+, mixtures of stereoisomers (cone, partial cone, and 1,3-alternate) were obtained. [ABSTRACT FROM AUTHOR]

Published
2022
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48. Electrochemical Sensing of Interactions between DNA and Charged Macrocycles

Author

Kulikova, T., Padnya, P., Shiabiev, I., Rogov, A., Stoikov, I., Evtugyn, G., Kulikova, T., Padnya, P., Shiabiev, I., Rogov, A., Stoikov, I., and Evtugyn, G.

Abstract

In this work, we investigated aggregation of native DNA and thiacalix[4]arene derivative bearing eight terminal amino groups in cone configuration using various redox probes on the glassy carbon electrode. It was shown that sorption transfer of the aggregates on the surface of the electrode covered with carbon black resulted in changes in electrostatic interactions and diffusional permeability of the surface layer. Such changes alter the signals of ferricyanide ion, methylene green and hydroquinone as redox probes to a degree depending on their specific interactions with DNA and own charge. Inclusion of DNA in the surface layer was independently confirmed by scanning electron microscopy, electrochemical impedance spectroscopy and experiments with doxorubicin as a model intercalator. Thermal denaturing of DNA affected the charge separation on the electrode interface and the signals of redox probes. Using hydroquinone, less sensitive to electrostatic interactions, made it possible to determine from 10 pM to 1.0 nM doxorubicin (limit of detection 3 pM) after 10 min incubation. Stabilizers present in the commercial medications did not alter the signal. The DNA sensors developed can find future application in the assessment of the complexes formed by DNA and macrocycles as delivery agents for small chemical species. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Published
2021

49. Synthesis, aggregation and chymotrypsin inhibition by tryptophan derivatives of thiacalix[4]arene

Author

Padnya, P. L., Shiabiev, I. E., Potrekeeva, О. S., Mostovaya, О. А., and Stoikov, I. I.

Subjects
CHYMOTRYPSIN INHIBITION, NANOPARTICLES, SYNTHESIS, THIACALIX[4]ARENE, SELF-ASSEMBLY
Abstract

Modulation of the catalytic activity of enzymes is widely used in various fields of human activity, such as medical applications, in agriculture and food industry. Currently, the attention of researchers has shifted to the search for modulators of enzyme activity based on polyfunctional building blocks, such as fullerenes, nanotubes, macrocyclic compounds. The attractiveness of macrocycles is due to their structural features, which make it easy to fix the spatial arrangement of large number of binding groups, capable of providing non-covalent interactions with guest molecules, which makes it possible to create ligands based on them for various kinds of biomolecules, including enzymes. This work was supported by the RFBR (grant 18-03-00315) and the grant of the President of the Russian Federation for state support of young Russian scientists – candidates of sciences (MK-12.2020.3).

Published
2020

50. Impedimetric determination of kanamycin in milk with aptasensor based on carbon black‐oligolactide composite

Author

Kulikova, T., Gorbatchuk, V., Stoikov, I., Rogov, A., Evtugyn, G., Hianik, T., Kulikova, T., Gorbatchuk, V., Stoikov, I., Rogov, A., Evtugyn, G., and Hianik, T.

Abstract

The determination of antibiotics in food is important due to their negative effect on human health related to antimicrobial resistance problem, renal toxicity, and allergic effects. We propose an impedimetric aptasensor for the determination of kanamycin A (KANA), which was assembled on the glassy carbon electrode by the deposition of carbon black in a chitosan matrix followed by carbodiimide binding of aminated aptamer mixed with oligolactide derivative of thiacalix[4]arene in a cone configuration. The assembling was monitored by cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy. In the presence of the KANA, the charge transfer resistance of the inner interface surprisingly decreased with the analyte concentration within 0.7 and 50 nM (limit of detection 0.3 nM). This was attributed to the partial shielding of the negative charge of the aptamer and of its support, a highly porous 3D structure of the surface layer caused by a macrocyclic core of the carrier. The use of electrostatic assembling in the presence of cationic polyelectrolyte decreased tenfold the detectable concentration of KANA. The aptasensor was successfully tested in the determination of KANA in spiked milk and yogurt with recoveries within 95% and 115%. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

Published
2020

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