Effects of molecular weight and ratio of guluronic acid to mannuronic acid on the antioxidant properties of sodium alginate fractions prepared by radiation-induced degradation

• Published in: Applied radiation and isotopes 2011, Vol.69 (1), p.126-129
• Main Author: Sen, Murat
• Format: Article
• Language: English
• Subjects: Alginates - chemistry; Antioxidant properties; Antioxidants - chemistry; Biphenyl Compounds - chemistry; Free Radical Scavengers - chemical synthesis; Free Radical Scavengers - chemistry; Gamma Rays; Hexuronic Acids - chemistry; Molecular Weight; Picrates - chemistry; Radiation-induced degradation; Sodium alginate
• ISSN: 0969-8043; 1872-9800
• DOI: 10.1016/j.apradiso.2010.08.017

In this study, the effects of the molecular weight and ratio of guluronic acid (G) to mannuronic acid (M), G/M, of some sodium alginate (NaAlg) fractions on their antioxidative properties were investigated. Low-molecular-weight-fractions with various G/M were prepared by gamma radiation-induced degradation of NaAlg. Change in their molecular weight was monitored. Antioxidant properties of the fractions with various molecular weight and G/M were evaluated by determining the scavenging ability of 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH ). 50% inhibition concentrations of the 50 kGy-irradiated NaAlgs having molecular weights of 20.5, 17.7, and 16.0 kDa were found to be 11.0, 18.0, and 24.0 mg/ml, respectively, whereas the fractions of the same molecular weight with a lower G/M exhibited a better DPPH scavenging activity. The results demonstrated that its molecular weight and G/M were important factors in controlling the antioxidant properties of NaAlg.