NMR spectroscopy of polysaccharide derivatives and their molecular structure. Review

Usmanov, T. I.

doi:10.1016/0032-3950(91)90116-8

Cited by 9 publications

(4 citation statements)

References 78 publications

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“…Position of Methacryloyl Group on the Glucopyranose Ring. Knowing that the methacryloyl group is directly attached to the glucose unit in dextran enables the determination of the position of this group at the glucopyranose ring . It has been reported 10 that esterification of a hydroxyl group of glucopyranosyl compounds, including dextran, causes a downfield shift (+0.9 to +1.9 ppm) of the resonance of the carbon directly attached to the ester, whereas the resonance of adjacent carbons is shifted upfield (−1.8 to −3.3 ppm).…”

Section: Resultsmentioning

confidence: 99%

Reaction of Dextran with Glycidyl Methacrylate: An Unexpected Transesterification

et al. 1997

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Section: Resultsmentioning

confidence: 99%

Reaction of Dextran with Glycidyl Methacrylate: An Unexpected Transesterification

et al. 1997

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“…It contains no signals of hemiacetal bonds C-O-C in the 100-85 ppm region ( Figure 6). Furthermore, the spectrum contains signals of the anhydroglucose reduced unit (IV): 103.79 ppm -C″′(1); 81.89 ppm -C″′(5); 79.80 ppm -C″′(4); 71.20 ppm -C″′(7); 70.05 ppm -C″′ (6). The assignment was based on an incremental scheme for determining chemical shifts.…”

Section: Resultsmentioning

confidence: 99%

Study of the Chemical Structure of Dialdehyde Carboxymethyl Cellulose Produced by Periodate Oxidation under Different Conditions

Dyatlov

Gumnikova

Grebeneva

et al. 2015

International Polymer Science and Technology

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13 C nuclear magnetic resonance, paramagnetic resonance, and ultraviolet spectroscopy and highresolution gel permeation chromatography were used to investigate the process of periodate oxidation of carboxymethyl cellulose and the structure and molecular weight characteristics of its oxidised forms produced under different conditions. It was shown that, in solution and in the solid state, aldehyde groups in the oxidised units exist in the form of cyclic hemiacetals. An examination was made of the existence of all the main cyclic intramolecular hemiacetal structures, and the most probable were proposed. The influence of the degree of periodate oxidation on the molecular weight characteristics and hydrolytic stability of dialdehyde carboxymethyl cellulose was studied.

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“…2) in the reaction with potassium 1-naphthyl acetate was evaluated by 13C NMR, which has been suggested as an adequate method to determine the substitution patterns of polysaccharides derivatives'. 12).…”

Section: Resultsmentioning

confidence: 99%

Synthesis and controlled release behaviour of dextran bioactive esters by direct reaction of dextran with the potassium salts of bioactive carboxylic acids

Macías

Sánchez‐Chaves

Rodrı́guez

et al. 1997

Macro Chemistry & Physics

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This work deals with the coupling of model bioactive carboxylic acids (l-naphthylacetic acid, 2-(6-methoxy-2-naphthyl)propionic acid (naproxen) and nicotinic acid) to dextran by direct reaction with their potassium salts using pyridine/sulfonyl chloride as activating agent. The structure of the resulting polymeric derivatives was determined by means of 'H and I3C NMR spectroscopy. The influence of the pyridine concentration, the type of sulfonyl chloride and the temperature on the reaction of dextran with potassium I-naphthyl acetate was evaluated. The activation energy was found to be 65,7 kJ/mol. 13CNMR spectra at 75,4 MHz of partially modified dextran with 1-naphthyl acetate groups were studied in order to evaluate the selectivity of the reaction between dextran and potassium 1-naphthyl acetate. Analysis of the spectra of ring carbons in the anhydroglucose units shows that the reactivity of the individual hydroxyl groups decreases in the order C2 > C4 > C3. The hydrolysis in the heterogeneous phase of some dextran polymers partially modified with 1-naphthyl acetate groups shows that the release of the bioactive compound is dependent on the hydrophilic character of the polymer as well as the pH value of the medium.Referring to the coupling of bioactive carboxylic acids to dextran, the stimulation of the direct reaction by using specific activators, such as dicyclohexylcarbodiimide, proved to be partially successful5). On the other hand, the pyridinelp-toluenesulfonyl chloride system has been successfully used as an appropriate activating agent for the direct acylation, in the heterogeneous phase, of cellulose with the carboxylate salts 0 1997, Hiithig &

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NMR spectroscopy of polysaccharide derivatives and their molecular structure. Review

Cited by 9 publications

References 78 publications

Reaction of Dextran with Glycidyl Methacrylate: An Unexpected Transesterification

Reaction of Dextran with Glycidyl Methacrylate: An Unexpected Transesterification

Study of the Chemical Structure of Dialdehyde Carboxymethyl Cellulose Produced by Periodate Oxidation under Different Conditions

Synthesis and controlled release behaviour of dextran bioactive esters by direct reaction of dextran with the potassium salts of bioactive carboxylic acids

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