Abstract:

In order to enhance the extraction of active components from plant materials and realize the reuse of enzyme,an intelligent gel,namely N-succinyl-chitosan ( NSC) ,was used as a support to immobilize cellulase. In the investigation,first,the structure of NSC was characterized via the FT-IR and the XRD,and the pH sensitivity of NSC was also discussed. Then,the conditions of NSC-immobilized cellulase ( NSCC) were optimized. Finally,the extraction of flavonoids from Ginkgo biloba leaf powders was carried out in the presence of NSCC,and the optimal temperature and pH value of NSCC for the extraction were determined. The results indicate that the production of NSC is due to the reaction of succinyl groups and the —NH2 groups in chitosan,that the crystalline region of chitosan becomes small due to the introduction of succinyl groups,that both NSC and NSCC possess similar pH-sensitive reversible solubility,that NSCC can be obtained under the optimal immobilization conditions of pH 5. 0,10mg of 1-( 3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride ( EDC) dosage and 15 mg of cellulase dosage,that NSCC with good reusability remarkably improves the extraction yield of flavonoids from Ginkgo biloba leaf powders,which is only a little less than that by using free cellulase,and that the optimal temperature and pH value of NSCC for the extraction are respectively 45 ～ 55℃ and 5. 0 .

Key words: N-succinyl-chitosan, cellulase, immobilization, active component, extraction