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1.
Инвентарный номер: нет.
   
   N 10


   
    N-(2-Carboxyethyl)chitosans: Regioselective synthesis, characterisation and protolytic equilibria [Text] / Yu. A. Skorik, C. A. R. Gomes, M. T.S.D. Vasconcelos, Yu. G. Yatluk // Carbohydrate Research. - 2003. - Vol. 338, № 3. - P271-276
ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
CARBOXYETHYLATION POLYSACCHARIDES -- N-(2-CARBOXYETHYL)CHITOSAN -- POLYAMPHOLYTE
Аннотация: N-(2-Carboxyethyl)chitosans were obtained by reaction of low molecular weight chitosan with a low degree of acetylation and 3-halopropionic acids under mild alkaline media (pH 8-9, NaHCO3) at 60°C. The chemical structure of the derivatives obtained was determined by 1H and 13C NMR spectroscopies. It was found that alkylation of chitosan by 3-halopropionic acids proceeds exclusively at the amino groups. The products obtained are described in terms of their degrees of carboxyethylation and ratio of mono-, di-substitution and free amine content. The protonation constants of amino and carboxylate groups of a series of N-(2-carboxyethyl)chitosans were determined by pH-titration at ionic strength 0.1 M KNO3 and 25°C. © 2002 Elsevier Science Ltd. All rights reserved.

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2.
Инвентарный номер: нет.
   
   N 10


   
    N-alkylation of chitosan by beta-halopropionic acids in the presence of various acceptors [Text] / A. V. Pestov, Yu. A. Skorik, G. Kogan, Yu. G. Yatluk // Journal of Applied Polymer Science . - 2008. - Vol. 108, № 1. - P119-127
ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Аннотация: N-carboxyethylation of chitosan by -halopropionic acids in the presence of various proton and halogen ion acceptors was investigated. It has been observed that carboxyethylation of chitosan in aqueous medium is accompanied by the by-processes of hydrolysis and dehydrohalogenation of the -halopropionic acids yielding -hydroxypropionic acid, bis(2-carbox-yethyl) ether, and acrylic acid. Degree of carboxyethyl substitution (DS) of chitosan and the relative rates of the by-processes varied significantly depending on the conditions used and nature of the proton or halogen ion acceptor. At carboxyethylation of chitosan with the alkaline -bromopropionates, the DS increased in the order Cs+ Rb- K+ sim; Na+ Li-.

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3.
Инвентарный номер: нет.
   
   A 62


   
    Antioxidant and antimutagenic activity of N-(2-carboxyethyl)chitosan [Text] / G. Kogan, Yu. A. Skorik, I. Zitnanova, L. Krizkova, Z. Durackova, C. A. R. Gomes, Yu. G. Yatluk, J. Krajcovic // Toxicology and Applied Pharmacology . - 2004. - Vol. 201, № 3. - P303-310 : ил. - Библиогр.: с. 309-310 (49 ref.)
ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Кл.слова (ненормированные):
CARBOXYETHYLATION -- CHITOSAN -- EUGLENA GRACILIS -- OFLOXACIN -- ANTIOXIDANT -- ANTIMUTAGENICITY
Аннотация: The antioxidant and antimutagenic activities of the novel carboxyethyl derivatives of chitosan with three different degrees of substitution have been assayed in vitro in the unicellular flagellate Euglena gracilis subjected to the action of genotoxic agents acridine orange and ofloxacin. It has been demonstrated that chitosan derivatives exhibit concentration-dependent protective antigenotoxic activity against both mutagens. It is suggested that different mechanisms may be involved in its protective action—antioxidant activity in case of ofloxacin-induced DNA damage, as well as possible interaction with the cell membrane that prevents acridine orange from reaching the genetic compartments and subsequent damaging DNA through intercalative binding. Direct adsorption of acridine orange on chitosan derivatives was ruled out as a possible mechanism of protection on the basis of spectrophotometric measurements. Dependence of the antimutagenic properties of the studied chitosan derivatives on the degree of substitution was reversed in experiments involving acridine orange and ofloxacin, which also indicated different mechanisms of protection involved in these two cases.????

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4.
Инвентарный номер: нет.
   
   H 43


   
    Heavy metals removal by flocculation/precipitation using N-(2-carboxyethyl)chitosans [Text] / S. YU. Bratskaya, A. V. Pestov, Yu. G. Yatluk, V. A. Avramenko // Colloids and Surfaces A: Physicochemical and Engineering Aspects. - 2009. - Vol. 339, № 1-3. - P140-144
ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Аннотация: Here we report on solution properties and flocculation performance of polyampholyte chitosan derivatives - N-carboxyethylated chitosans (CEC) - synthesized "in gel" by treatment of chitosan with acrylic acid. We show that carboxyethylation with the substitution degrees (DS) from 0.7 to 1.6 yields water-soluble derivatives, whose isoelectric points (IEP) range from 6.30 to 3.55. At pH 7.5 interaction of negatively charged CEC derivatives with positively charged colloids of the heavy metal hydroxides (Zn2+, Cu2+, Ni2+), serving as a model of postgalvanic wastewaters, results in lowering of electrokinetic potential of the hydroxide colloids and their precipitation at appropriate flocculant dose. Investigations of CEC flocculation performance depending on pH and DS show that the efficiency of metal removal decreases in the row Cu2+ Zn2+ Ni2+ corresponding to the row of the hydroxocomplex stability for these metals. The higher was pH of the system and DS of CEC derivative, the narrower was the flocculation window and the stronger was negative effect of flocculant overdosing on the efficiency of heavy metal removal. Based on the estimation of floc settling rates and the residual metal concentrations, we have concluded that the optimal DS of CEC derivatives for the precipitation of metal hydroxides is 0.7-1.0

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5.
Инвентарный номер: нет.
   
   P 49


    Pestov, A. V.
    In-gel carboxyethylation of chitosan by beta-halopropionic acids [] : доклад, тезисы доклада / A. V. Pestov, Yu. A. Skorik, Yu. G. Yatluk // 10-th International Conference on Chitin and Chitosan - 7th International Conference of the European Chitin Society, Le Corum, Montpellier, France, 6-9 September 2006 : book of abstracts . - Le Corum, Montpellier (France), 2006. - 76 (PC 11)
ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ

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6.
Инвентарный номер: нет.
   
   Х 37


   
    Хемоселективное карбоксиэтилирование хитина и хитозана и антимутагенная активность N-(2-карбоксиэтил)хитозанов [] = Chemoselective carboxyethylation of chitin and chitosan and antimutagenic activity of the reaction products : доклад, тезисы доклада / Ю. А. Скорик, Г. Коган, Л. Крижкова, Ю. Г. Ятлук, А. В. Пестов, К. А.Р. Гомеш, Ю. Крайчович // Современные перспективы в исследовании хитина и хитозана : материалы VII Международной конф., СПб, 15-18 сент. 2003 г. : докл. . - СПб., 2003. - С. 46-50. - Библиогр.: с. 50 (11 назв.)
ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ

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7.
Инвентарный номер: нет.
   
   N 52


   
    New hybrid chelating sorbents with grafted 3-aminopropionate groups based on mixed silicon, aluminum, titanium, or zirconium oxides [Electronic resource] / Yu. G. Yatluk, N. A. Zhuravlev, O. V. Koryakova, L. K. Neudachina, Yu. A. Skorik // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2005. - Vol. 54, № 8. - P1836-1841
ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Аннотация: A series of new hybrid organo-inorganic sorbents with the 3-aminopropionate chelating group was synthesized. The synthesis includes the copolycondensation (sol—gel method) of tetraethoxysilane, 3-aminopropyltriethoxysilane, and several modifiers (MeSi(OEt)3, EtSi(OEt)3, Ti(OEt)4, AlONO3, ZrOCl2) followed by carboxyethylation with acrylic acid. The obtained chelating sorbents were characterized by elemental analysis, FT-IR and 1H NMR spectroscopy, and thermogravimetry. The N-carboxylated sorbents have a higher sorption capacity with respect to metal ions (0.5–0.9 mmol g?1, pH 6.3, NH4OAc, 20 °C) than the starting sorbents with the primary amino group (0.05–0.2 mmol g?1) and manifest high selectivity for copper(II) ion extraction

\\\\Expert2\\nbo\\Russian Chemical Bulletin\\2005, 54 (8), 1836.pdf
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8.
Инвентарный номер: нет.
   
   S 98


   
    Synthesis and sorption properties of new hybrid chelating sorbents with ?-alanine functional groups [Electronic resource] / Yu. G. Yatluk, D. V. Eremin, L. K. Neudachina, Yu. A. Skorik // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2004. - Vol. 53, № 12. - P2730-2735
ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Аннотация: A series of gamma-aminopropylsilylated sorbents was obtained from different oxide supports (silica gels, silica fillers, macroporous glasses, alumina) and by the direct synthesis (hydrolytic polycondensation of tetraalkoxysilanes with gamma-aminopropyltriethoxysilane). The highest degree of immobilization was achieved for silicas, while the most convenient solvent was methanol. Sorbents with beta-alanine functional groups were obtained by the subsequent reaction with acrylic acid. The degree of beta-carboxyethylation was 1.3–1.9, and the highest content of functional groups (vCOOH = 3.23 mmol g–1) was achieved for carboxyethylated xero gel synthesized by the copolycondensation of tetraethoxysilane with -aminopropyltriethoxysilane. The sorbents containing beta-alanine possess a higher selectivity of Cu2+ ion sorption than the initial gamma-aminopropylsilylated sorbents

\\\\Expert2\\nbo\\Russian Chemical Bulletin\\2004, 53 (12), 2730.pdf
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9.
Инвентарный номер: нет.
   
   S 45


   
    Selective mоnо-N-2-carboxyethylation of chitosan in the presence of magnesium halides [Text] / A. V. Pestov, M. I. Kodess, E. G. Matochkina, Yu. G. Yatluk // Carbohydrate Polymers. - 2011. - Vol. 86, № 2. - P783-788. - Bibliogr. : p. 787-788 (19 ref.)
ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ
Аннотация: The solubility of chitosan in aqueous solutions of lithium and magnesium halides varies in the order: LiCl LiBr LiI; MgCl2 MgBr2 MgI2. A method for selective production of mono-N-(2-carboxyethyl)chitosan (NCE-chitosan) was developed by synthesis in gel (concentration of chitosan 4-20%) of the magnesium halides solution (1.1-3.5 M) using acrylic acid. Using for reaction of MgI2 or MgBr2 provides relative greater amount of the monosubstituted amino groups (73-87%) in comparison with their absence (50-70%) at the high degree of substitution (DS) more than 0.7. DS of the prepared NCE-chitosan and the ratios mono-: disubstitution of amino groups was determined by 1H NMR spectroscopy. The chemical structure of the obtained NCE-chitosan was characterized by FT-IR and 13C NMR spectroscopies

\\\\Expert2\\nbo\\Carbohydrate Polymers\\2011, v. 86, p.783.pdf
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10.
Инвентарный номер: нет.
   
   I-57


   
    In-gel carboxyethylation of chitosan and the molecular architecture of the products [Text] / A. V. Pestov, G. Kogan, Yu. A. Skorik, Yu. G. Yatluk, M. Pajtinka // 1st European chemistry Congress. - Budapest, Hungary, 2006. - Vol. 2. - P295. - Bibliogr. : p. 295 (2 ref.)
ББК 54
Рубрики: ХИМИЧЕСКИЕ НАУКИ

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