New hyaluronan chemical derivatives. Regioselectively C(6) oxidized products

Hyaluronan (HA) has been regioselectively oxidized so to transform nearly q uantitatively the primary alcoholic functions of D-N-acetylglucosamine resi dues in carboxylate groups. The resulting product (HAOX) has been character ized by means of H-1 NMR, viscosity, and spectroscopic measurements in aque ous media. A comparative analysis of Zn(II) uptake and of methylene blue bi nding by HA and HAOX in aqueous solution has been also carried out (FTIR, U V absorption, and CD experiments). HAOX exhibits polyelectrolytic features traceable to a doubling of chains charge density with respect to native HA and to the disruption of the intrachain hydrogen bonds prevailing in the la tter.