Viscosity and optical activity of chondroitin sulfate C

Chondroitin sulfate C (CSC), isolated from shark vertebral mucoprotein, has a molecular weight of 0.2 × 10 4 –5.5 × 10 4 in both NaCl and CaCl 2 solutions. Optical rotatory dispersion and circular dichroism of CSC reveal a strong, negative, optically active band near 210 mμ, arising from the carboxylate and N ‐acetyl groups. Results of similar studies of glucuronic acid and N ‐acetyl‐ D ‐galactosamine suggest that the N ‐acetyl group contributes more to the rotations of CSC than does the carboxylate group, but the acidification of the carboxylate groups largely accounts for the change in magnitude and position of the circular dichroic bands of CSC at low pH.