کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1378814 982010 2009 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
TEMPO-mediated oxidation of (1 → 3)-β-d-glucans
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
TEMPO-mediated oxidation of (1 → 3)-β-d-glucans
چکیده انگلیسی

The 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation was applied to water-insoluble (1 → 3)-β-d-glucans, paramylon and curdlan, to prepare water-soluble oxidized products. When the addition level of NaClO used as the primary oxidant was 15 mmol per gram of the polysaccharide in the combination with catalytic amounts of TEMPO and NaBr under aqueous conditions at pH 10, water-soluble TEMPO-oxidized products were obtained quantitatively within 100 min. 13C NMR analysis of the TEMPO-oxidized products revealed that the C6 primary hydroxyl groups of both paramylon and curdlan were completely converted to carboxylate groups by the oxidation. Thus, new (1 → 3)-β-d-polyglucuronic acid sodium salts having almost homogeneous chemical structures can be obtained. The highly crystalline paramylon took longer time for the complete oxidation of the C6 primary hydroxyls to carboxylate groups than curdlan. However, remarkable depolymerization occurs on main chains during the oxidation, and the degrees of polymerization of the water-soluble TEMPO-oxidized products prepared from paramylon and curdlan were only 68 and 86, respectively.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Carbohydrate Polymers - Volume 77, Issue 2, 10 June 2009, Pages 300–305
نویسندگان
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