The Preparation Of C_3,6-Acyl Thiosemicarbazone Derivatives Of Chitosan And The Study On Their Antioxidant Activities

As a kind of Schiff base compound, thiosemicarbazone has been widely concerned by people from all walks of life since it was found to have good biological activities. So far, people have synthesized a variety of thiosemicarbazone derivatives and explored their antioxidant, antiviral, antibacterial and other biological activities. However, the application of this kind of compounds was terribly limited due to their toxicity. Chitosan is non-toxic and antioxidant, we attempted to combine two of them to prepare a new sort of compounds with low toxicity and high antioxidant activities in the meanwhile.Thirty novel acyl thiosemicarbazone derivatives of Chitosan were prepared with the located protection method in this essay for the first time in total. Specific means as follows: use acetyl chloride (chloroacetyl chloride, benzoyl chloride) to modify hydroxyl with acylating located method under the presence of phthalic anhydride protecting amino. Eventually, the C3,6-acetylation (chloroacetyl ation, benzoyl ation) of substituted benzene amino thiosemicarbazone chitosans were prepared successfully. The structure of them was characterized under the help of infrared spectroscopy and elemental analyses besides that the antioxidant activities of these new derivatives were also researched, including hydroxyl free radical/superoxide anion/DPPH free radical’s scavenging effects and reducing power. The results showed that the new derivatives had better antioxidant activities relatively, therefore they might have the potential to be further developed into antioxidant reagents.