Studies on catalytic spectrophotometry using #beta#-cyclodextrin polymer-Schiff base metal complex as mimetic enzyme

摘要

A novel catalytic spectrophotometric method for the determination of superoxide anion radical (O_2~-) and superoxide dismutase (SOD) activity is proposed. The method is based on the coupling reaction of 2,4-dichlorophenol (2,4-DCP) and 4-amino antipyrine in the presence of H_2O_2, catalyzed by a Schiff base metal complex included by #beta#-cyclodextrin cross-linked polymer (#beta#-CDP) as a mimetic enzyme. The contribution describes the design and synthesis of a novel Schiff base, salicylidene-2-amino-4-phenylthiazole (SAPTS) as well as a series of its metal complexes: M(II)-(SAPTS)_2[M:Cu(II),Co(II),Zn(II),Ni(II)], among which Cu(II)-(SAPTS)_2 exhibits efficient horseradish peroxidase-like catalytic activity. Investigations of the optimum reaction conditions, the mechanism, and effects of coexisting substances are presented. The linear calibration range and the detect limit (3#sigma#) of the developed method for superoxide is from 0.0 to 1.0 X 10~(-3) and 7.54 X 10~(-7) M, respectively. The determinations of SOD activity in human/rat blood, garlic, onion and scallion serve as models for the proposed method. A comparison of the results with established classical analysis is satisfactory.