Exact determination of the degree of substitution of high molar mass hyaluronan by controlling the conformation in solution.

Carbohydr Polym

Division of Macromolecular Chemistry, Institute of Applied Synthetic Chemistry, Vienna University of Technology, 1060 Vienna, Austria.

Published: January 2019


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Article Abstract

The purpose of the present study was the development of an accurate method to determine the degree of substitution (DS) of modified hyaluronic acid (HA) by proton nuclear magnetic resonance (H NMR) spectroscopy. The influence of the effect of ionic strength and pH on H NMR spectra of HA was studied. The results showed a correlation between the conformation of HA in solution and the quality of the H NMR spectra. The best spectra with full proton mobility are obtained when HA is dissolved in DO with 2 M NaCl or DO with 0.1 M NaOD with a maximum concentration of 5 mg/ml. Under those conditions the size of the polymer coils is reduced below the concentration of chain overlap point, all the protons show the same response and a correct degree of substitution can be determined.

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http://dx.doi.org/10.1016/j.carbpol.2018.10.003DOI Listing

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