Biophysical properties of carboxymethyl derivatives of mannan and dextran.

Mannan from Candida albicans, dextran from Leuconostoc spp. and their carboxymethyl (CM)-derivatives were tested on antioxidant and thrombolytic activities. As antioxidant tests, protection of liposomes against OH radicals and reducing power assay were used. Dextran and mannan protected liposomes in dose-dependent manner. Carboxymethylation significantly increased antioxidant properties of both CM-derivatives up to concentration of 10mg/mL, higher concentrations did not change the protection of liposomes. The reducing power of CM-mannan (DS 0.92) was significantly lower (P<0.05) than underivatized mannan. No reductive activity was found for dextran and CM-dextran. All CM-derivatives demonstrated statistically significant increasing activity compared with underivatized polysaccharides. The highest thrombolytic activity was found using CM-mannan (DS 0.92). The clot lysis here amounted to 68.78 ± 6.52% compared with 0.9% NaCl control (18.3 ± 6.3%). Three-dimensional surface profiles of mannan, dextran, and their CM-derivatives were compared by atomic force microscopy.