Preparation Of Chitosan Derivatives Metal Complexes Its Antimicrobial, Antioxidant Activity Studies

Some kinds of complexes of Chitosan derivatives with the metal were prepared,and their antibacterial activity and antioxidant activity were also studied in this paper. Chitosans with low molecular weight were prepared by using microwaveirradiation. The effects of various factors:reaction solution,oxidant/Chitosan ratio,microwave irradiation power and time on the degradation reaction were investigatedin this paper. The results showed that chitosans with 10-100 thousand molecularweight were prepared in 1-6 minutes by microwave irradiation under the differentreaction conditions. At the same time the yield was higher and repetition was well. The carboxymethyl Chitosan has been prepared under microwave irradiationcondition. Furthermore, the complexes of Chitosan with copper( Ⅱ ),zinc( Ⅱ ),chromium(Ⅲ) and the complexes of carboxymethyl Chitosan with copper(Ⅱ),zinc( Ⅱ ) have been synthesized by metal solution reacted with Chitosan orcarboxymethyl Chitosan. Preparing conditions of the complexes chitosan withchromium(Ⅲ) were investigated. The configurations of them were analyzed by UVand IR spectra. For the first time, chitosan and its complexes with copper(Ⅱ) or zinc(Ⅱ) weresulfation modified by using microwave irradiation. The metal complexes withsulfation chitosan have been synthesized. All were soluble in water and vitriol groupcontent was over 30%. The structures of them are characterized by IR and NMRspectra. The free radical scavenging effects on superoxide anion radical byNADH-PMS-NBT system and hydroxyl radical by EDTANa2·Fe(Ⅱ)-H2O2 system ofthese complexes were studied. The antioxidant ability of them was analyzed from it.The results demonstrated that all of the complexes showed excellent ability forscavenging the superoxide anion radical and hydroxyl radical. Three kinds ofcopper(Ⅱ) complexes and the low-molecular-weight complexes of sulfation chitosanwith zinc(Ⅱ) displayed the highest scavenging effects on the superoxide anion radical.When mass concentration of samples was 25μg/mL,the scavenging activity were89.18-94.18%. The complexes chtiosan with zinc( Ⅱ )and the complexes ofcarboxymethyl Chitosan with zinc(Ⅱ) displayed the highest scavenging effects on thehydroxyl radical. When mass concentration of samples was 1.6mg/mL,the scavengingactivity were 72.78%, 73.98%.The antioxidation mechanism of these samples werealso investigated. The inhibition effects of the complexes on the four kinds of the growth of croppathogenic fungi were tested on PDA medium.The results showed that the differentmolecular weight of the complexes of Chitosan with copper(Ⅱ)or zinc(Ⅱ), thecomplexes of carboxymethyl Chitosan with copper(Ⅱ) and the low-molecular-weight iiicomplexes of sulfation chitosan with copper(Ⅱ) had excellent inhibition on Valsamali. The low-molecular-weight complexes of chitosan with copper( Ⅱ ) hadinhibition on Botyosphaeria berengeriana. All of samples had no inhibition onFusarinm oxysporium.f.sp.vasinfectum and Alternaria Solani under this testconditions. The effects of the structures, the metal content and molecular weight ofthe complexes on inhibition activity wree investigated. The results showed that the complexes of chitosan and its with copper(Ⅱ),zinc(Ⅱ) had excellent ability for scavenging the superoxide anion radical andhydroxyl radical and had also inhibition effects on the growth of crop pathogenicfungi(Valsa mali). It was proved that the metal ion advanced biology activity of thesecomplexes, the complexes added their activities. It was estabished the foundations forstudy and apply for the future.