Effects of ascorbate and hydroxyl radical degradations on the structural, physicochemical, antioxidant and film forming properties of chitosan.

In this study, chitosan (CS) was degraded by ascorbate radical (Asc) and hydroxyl radical (OH), respectively. The structural, physicochemical, antioxidant and film forming properties of Asc and OH degraded CS were compared for the first time. Results showed the structure and physicochemical property of Asc degraded CS were significantly different from those of CS.

Reaction Mechanisms and Structural and Physicochemical Properties of Caffeic Acid Grafted Chitosan Synthesized in Ascorbic Acid and Hydroxyl Peroxide Redox System.

The ascorbic acid (AA) and hydroxyl peroxide (HO) redox pair induced free radical grafting reaction is a promising approach to conjugate phenolic groups with chitosan (CS). In order to reveal the exact mechanisms of the AA/HO redox pair induced grafting reaction, free radicals generated in the AA/HO redox system were compared with hydroxyl radical (OH) produced in the Fe/HO redox system. Moreover, the structural and physicochemical properties of caffeic acid grafted CS (CA-g-CS) synthesized in these two redox systems were compared.

Synthesis, characterization, bioactivity and potential application of phenolic acid grafted chitosan: A review.

In recent years, increasing attention has been paid to the grafting of phenolic acid onto chitosan in order to enhance the bioactivity and widen the application of chitosan. Here, we present a comprehensive overview on the recent advances of phenolic acid grafted chitosan (phenolic acid-g-chitosan) in many aspects, including the synthetic method, structural characterization, biological activity, physicochemical property and potential application. In general, four kinds of techniques including carbodiimide based coupling, enzyme catalyzed grafting, free radical mediated grafting and electrochemical methods are frequently used for the synthesis of phenolic acid-g-chitosan.

Recent advances in endophytic exopolysaccharides: Production, structural characterization, physiological role and biological activity.

Endophytes are microorganisms that colonize living, internal tissues of plants without causing any immediate, overt negative effects. In recent years, both endophytic bacteria and fungi have been demonstrated to be excellent exopolysaccharides (EPS) producers. This review focuses on the recent advances in EPS produced by endophytes, including its production, isolation and purification, structural characterization, physiological role and biological activity.

Extraction, characterization and in vitro antioxidant activity of polysaccharides from black soybean.

Optimization of extraction conditions, preliminary characterization and in vitro antioxidant activity of polysaccharides from black soybean (BSPS) were investigated. The results of Box-Behnken design showed that the optimal extraction conditions for BSPS were as follows: ratio of water to material of 20 ml/g, extraction time of 6.4h and extraction temperature of 92 °C, with a corresponding yield of 2.