کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10597059 | 981955 | 2013 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Stability of (1 â 3)-β-polyglucuronic acid under various pH and temperature conditions
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Regioselective oxidation of C6 primary hydroxyls to carboxyls was applied to curdlan, to prepare a water-soluble (1 â 3)-β-polyglucuronic acid Na salt [(1,3)-β-PGluA], using a 4-acetamido-TEMPO/NaClO/NaClO2 oxidation system at pH 4.7. Changes in the chemical structure and degree of polymerization of (1,3)-β-PGluA treated in water at various temperatures and pHs were studied to evaluate the stability of (1,3)-β-PGluA to these treatments. This polyuronic acid was found to be stable, without any depolymerization, to treatment in water at pHs 1-9 and room temperature for up to 128 h; slight depolymerization was observed at pHs 11 and 13. When heated in water at pH 1 and high temperatures (1,3)-β-PGluA molecules were randomly depolymerized by hydrolysis, primarily forming glucuronic acid. In contrast, dicarboxylic-acid-type monomers containing ethylene carbons were formed from the C1-carboxyl or C1 reducing ends of (1,3)-β-PGluA molecules by treatment under alkaline conditions; this was initiated by β-alkoxy elimination, similar to the peeling-off reaction of cellulose.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Carbohydrate Polymers - Volume 97, Issue 2, 12 September 2013, Pages 413-420
Journal: Carbohydrate Polymers - Volume 97, Issue 2, 12 September 2013, Pages 413-420
نویسندگان
Erika Watanabe, Naoyuki Tamura, Shuji Fujisawa, Tsuguyuki Saito, Naoto Habu, Akira Isogai,