کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1378798 982010 2009 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Poly-acid properties of biosynthetic hyaluronan studied by titration
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Poly-acid properties of biosynthetic hyaluronan studied by titration
چکیده انگلیسی

In this study the poly-acid properties of biosynthetic hyaluronan produced by fermentation of Bacillus subtilis have been investigated. Potentiometric titration as well as 1H NMR titration have been used to determine the dissociation constants of the carboxylic group on hyaluronic acid. The intrinsic pKa and pKa, α=0.5 were determined in the presence of 0.1 M salt to be 2.99 and 3.37, respectively. The pKa, α=0.5 was found to be unaffected by variations in the ionic strength which is in good agreement with the fact that at α = 0.5, 50% of the carboxylic moieties on the hyaluronan are charged. On the other hand the intrinsic pKa was found to be dependent on the ionic strength until the Debye-Hückel screening length approaches the length of repeating disaccharide unit of hyaluronic acid.Our findings are in good agreement with previously determined dissociation constants for other sources of hyaluronan. We have also shown that 1H NMR spectroscopy is the preferred method for polyelectrolyte titration because of the ability to isolate the contribution of several ionisable groups on a polymer on molecular level.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Carbohydrate Polymers - Volume 77, Issue 2, 10 June 2009, Pages 194–200
نویسندگان
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