Chondroitin sulfate chemical structure

In order to shed more light on the Interaction of water with these mucopolysaccharides, we employ the DSC method to follow the melting behavior of aqueous solutions of the polysaccharides cooled to -50 C. The polymers chosen here are chondroitin sulfate A (Chn S-A), chondroitin sulfate C (Chn S-C), chondroitin (Chn), heparin (Hpn), and hyaluronic acid (HyA). Their chemical structures are shown in Figure 1. The DSC curves allow us to determine the amount of the non-freezing water In highly concentrated solutions, since any endothermic peak Is not observed for such solutions over a wide temperature range (17. 18). This paper will also describe the presence of more than one endothermic peak In the DSC curves for solutions of relatively low polymer concentrations. 

In all, eight glycosaminoglycans of essentially diflFerent chemical structures have been identified. Through the times, these glycosaminoglycans have been individually named in a number of ways, as shown in Table 1. Most of these names are used currently, and so the reader will find it useful to have this table available when consulting the primary literature. Where the term chondroitin sulfate appears in the more recent literature, this can mean chondroitin 4-sulfate or chondroitin 6-sulfate or a mixture of the two. The terms keratan sulfate I and keratan sulfate II are sometimes used to denote keratan sulfates of comeal and skeletal origin, respectively, there being some differences between the two. 

For example, polyaniline is not readily incorporated into wool structures, however, poly(2-methox-yaniline-5-sulfonic acid (PMAS) is (Figure 11.11). The PMAS can subsequently be used to template the aniline monomer before chemical oxidation. Biological molecules such as chondroitin sulfate, dextran sulfate, and DNA have been shown to be effective molecular templates for this purpose. 

The first and still only clue for a difference between the chemical structure of chondroitin 4-sulfate and chondroitin 6-sulfate was supplied by studies of the infrared spectra. An adsorption band corresponding to an axial sulfate group was observed in the 840 to 850 wave number region for chondroitin 4-sulfate, whereas this band shifted to the 815 to 825 wave number region for the 6-isomer, corresponding to an equatorial position. Since the only hydroxyl group, in equatorial position and available for... 

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