| Superoxide anion?O2-.?and hydrogen peroxide?H2O2?as the main toxic oxygen species can cause a series of problems such as food spoilage and human aging.Superoxide dismutase?SOD?as a natural scavenger can convert superoxide anion into oxygen and hydrogen peroxide.And catalase?CAT?can convert hydrogen peroxide into nontoxic oxygen and water.Therefore,these can be widely used in food,medicine,daily chemical and other fields.But in fact the application has been limited because the high cost of purifying and changes about the environment?such as temperature,pH,etc.?can affect natural enzymes.In order to solve these defects of natural SOD,a large number of metal complexes have been synthesized with SOD and CAT-like activity.On the other hand,some solid materials have been used as the carrier like silicon and ferroferric oxide to improve the stability and repeatability of mimic enzyme.Three superoxide dismutase and catalase mimics were synthesized and designed in this paper.The products were characterized by IR,TGA,AAS ? XPS and SEM.Superoxide dismutase activity is determined by NBT method and the CAT activity is mainly determined by eudiometry.The main results are as follows:?1?In order to simulate the structure of natural Mn-SOD,new silica microspheres were synthesized by grafting histidine.The silica particles as protein chain,histidine and carboxyl as ligands can chelat manganese ion to obtain mimic Mn-NPs.The unit of SOD activity IC50 is 0.012 mg/mL;The initial reaction rate of CAT activity V0 is 1.3×10-6mol?O2?/s.?2?Fe3O4 as the carrier was modified with the amido bond to obtain new Cu Zn nanoparticles with ligands of diethylenetriamine.Based on the magnetic characteristics,the mimic can be separated quickly from the reaction medium which can improve the repeating rate.The unit of SOD activity IC50 is 0.006 mg/mL;The initial reaction rate of CAT activity V0 is 1.06×10-6 mol?O2?/s.?3?Coordination sites such as hydroxyl and Schiff base react with metal manganese to synthesize salen scavenger?Mn-L3?.It has SOD-like and CAT-like activity.The unit of SOD activity IC50 is 0.045 mg/mL;The initial reaction rate of CAT activity V0 is9.67×10-7 mol?O2?/s. |
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