TITLE

Comprehensive analysis of the substitution pattern in dextran ethers with respect to the reaction conditions

AUTHOR(S)
Vollmer, Antje; Voiges, Kristin; Bork, Christian; Fiege, Kathrin; Cuber, Katja; Mischnick, Petra
PUB. DATE
November 2009
SOURCE
Analytical & Bioanalytical Chemistry;Nov2009, Vol. 395 Issue 6, p1749
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Dextrans from Leuconostoc ssp., α-1,6-linked glucans branched at O-3, were O-methylated in DMSO with lithium dimsyl and methyl iodide under various conditions. Methyl substituent distribution was comprehensively studied in the terminal, internal, and branched glucosyl units and along and over the dextran macromolecules. The order of reactivity was O-2 > O-4 ≥ O-3. The methyl pattern in the glucosyl units significantly deviates from a random distribution with enhanced amounts of un- and trisubstituted moieties. This deviation was found to proceed on macromolecular level by means of ESI-MS of perdeuteromethylated and partially depolymerized methyl dextrans. Heterogeneity was much more pronounced than for methyl amylose prepared under comparable conditions. DS gradients in and over the material are discussed with respect to dextran structure and the mechanism of Li dimsyl alkylation. For comparison, cyanoethyl dextrans were prepared by sodium hydroxide catalyzed addition of acrylonitrile. Monomer analysis of cyanoethyl dextrans revealed that this thermodynamically controlled reaction gave a random substitution pattern with 48% of cyanoethyl groups at O-2, 33% at O-4, and 19% at O-3. [Figure not available: see fulltext.]
ACCESSION #
44917216

 

Related Articles

  • Specific screening method for dextran and hydroxyethyl starch in human urine by size exclusion chromatography-in-source collision-induced dissociation-time-of-flight mass spectrometry. Kolmonen, Marjo; Leinonen, Antti; Kuuranne, Tiia; Pelander, Anna; Deventer, Koen; Ojanper�, Ilkka // Analytical & Bioanalytical Chemistry;Nov2011, Vol. 401 Issue 2, p563 

    The use of plasma volume expanders (PVE), such as dextran (DEX) and hydroxyethyl starch (HES), is prohibited in sports. DEX is a naturally occurring glucose polymer, whereas HES is synthetically produced from amylopectin starch by substitution with hydroxyethyl groups. In doping control, the...

  • Modification of polymer surfaces: optimization of approaches. Courtney, JM; Zhao, XB; Qian, H; Sharma, A // Perfusion;Jan2003 Supplement, Vol. 18, p33 

    Modification of polymer surfaces to achieve a surface with enhanced compatibility is an important means of obtaining improved biomaterials. Techniques are available for altering the hydrophilicity or charge of a surface, attaching macromolecules or attempting to resemble cell membranes. Relevant...

  • Mass Spectrometry of Polymers.  // LC-GC North America;May2003 Supplement, Vol. 21 Issue 5, pS35 

    Features the book 'Mass Spectrometry of Polymers,' edited by Giorgio Montaudo and Robert P. Lattimer.

  • Synthesis and Characterization of Biodegradable Polyurethane for Hypopharyngeal Tissue Engineering. Shen, Zhisen; Lu, Dakai; Li, Qun; Zhang, Zongyong; Zhu, Yabin // BioMed Research International;3/8/2015, Vol. 2015, p1 

    Biodegradable crosslinked polyurethane (cPU) was synthesized using polyethylene glycol (PEG), L-lactide (L-LA), and hexamethylene diisocyanate (HDI), with iron acetylacetonate (Fe(acac)3) as the catalyst and PEG as the extender. Chemical components of the obtained polymers were characterized by...

  • Static secondary ion mass spectrometry for the surface characterisation of individual nanofibres of polycaprolactone functionalised with an antibacterial additive. Royen, Pieter Van; Boschmans, Bart; Santos, Ana dos; Schacht, Etienne; Dubruel, Peter; Cornelissen, Ria; Beenaerts, Linda; Vaeck, Luc Van // Analytical & Bioanalytical Chemistry;Feb2011, Vol. 399 Issue 3, p1163 

    Electrospinning (ES) of polymer solutions generates non-woven webs of nanofibres. The fibre diameter ranges between 10 nm and 1 μm depending on the operating conditions. Surface functionalisation can be performed by the use of suitable additives. Detailed characterisation of the molecular...

  • Broad-spectrum drug screening of meconium by liquid chromatography with tandem mass spectrometry and time-of-flight mass spectrometry. Ristimaa, Johanna; Gergov, Merja; Pelander, Anna; Halmesmäki, Erja; Ojanperä, Ilkka // Analytical & Bioanalytical Chemistry;Sep2010, Vol. 398 Issue 2, p925 

    nalysis of the major drugs of abuse in meconium has been established in clinical practice for detecting fetal exposure to illicit drugs, particularly for the ready availability of the sample and ease of collection from diapers, compared with neonatal hair and urine. Very little is known about...

  • Cathode-induced luminescence quenching in polyfluorenes. Stoessel, M.; Wittmann, G.; Staudigel, J.; Steuber, F.; Bla¨ssing, J.; Roth, W.; Klausmann, H.; Rogler, W.; Simmerer, J.; Winnacker, A.; Inbasekaran, M.; Woo, E. P. // Journal of Applied Physics;5/1/2000, Vol. 87 Issue 9, p4467 

    We investigate the impact of the deposition of low work function metals such as calcium on thin layers of fluorene-type polymers by time-of-flight secondary ion mass spectroscopy. An implantation process rather than a slow metal diffusion is found to be the most probable source of metal...

  • Coatings hide implants from the body. Scholz, Carmen // Advanced Materials & Processes;Sep2013, Vol. 171 Issue 9, p15 

    The article reports that researcher Carmen Scholz of the University of Alabama in Huntsville is working to develop a biocompatible polymer that can cloak sensors implanted into body from the immune system.

  • A Mass-Spectrometric Study of the Behavior of Thermotropic Liquid-Crystalline Polymers on Heating. Pozdnyakov, O. F.; Redkov, B. P.; Egorov, E. A. // Technical Physics Letters;May2001, Vol. 27 Issue 5, p351 

    Physicochemical processes accompanying the thermal treatment of a liquid-crystalline aromatic copolyester Ultrax-4002 at temperatures in the vicinity of the thermotropic transition were studied by mass spectrometry in order to reveal possible features of the mechanism of polymer strengthening....

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics