Study On The Superoxide Dismutase And Catalase-Like Activities Of Simulant

Both Superoxide Dismutase(SOD) and Catalase(CAT) are important antioxidases in human body, which remove the oxidized species produced during the metabolize of cells, such as O2-·, ·OH and H2O2. However, with the aging of the human body, the antioxidases levels are declining. So these enzymes are of great significance in the aspects of treatment of disease, antiaging and human health.The natural enzymes with large molecular weights have lower cell permeability, easy inactivation and difficult to extract with high cost. Therefore, it is particularly important to synthesize mimics of natural antioxidant enzyme. Using silica nanoparticles as the carrier for the active ingredient is expected to synthesize high activity, good stability, easy recovery mimics, meanwhile.In this paper, we designed and synthesized a series of mimetic enzyme with silica nanoparticles as carriers, which modified by polyamine and Schiff base reduced compounds. Firstly, the effects of the reaction conditions on the size and morphology of the silica nanoparticles have been investigated, using tetraethoxysilane as raw material and ammonia as a catalyst. Then, the following works have been done using silica as a core:Mn,Cu contained and diethylenetriamine(DETA) or triethylenetetramine(TETA) modified silica nanoparticles were synthesized with ?-chloropropyl triethoxysilane(ACTES) as coupling agent; the SOD and CAT activities of the mimetics were investigated. The SOD activity of the mimetic enzyme modified triethylenetetramine was investigated with IC50 of 0.026 g·L-1 and the SOD activity of the mimetic enzyme modified triethylenetetramine was investigated with IC50 of 0.007 g·L-1and 0.003 g·L-1; the CAT activity of the mimetic enzyme modified polyamine was investigated;Mn and Cu complex silica nanoparticles modified Schiff base of Salicylaldehyde were synthesized with ?-Chloropropyl Triethoxysilane(ACTES) as coupling agent; the SOD activity of the mimetic enzyme was investigated with IC50 of 0.0051 g·L-1and 0.0048 g·L-1; the CAT activity of the mimetic enzyme modified Schiff base of Salicylaldehyde was investigated;Mn and Cu complex silica nanoparticles modified Schiff base of Methionine were synthesized with?-Chloropropyl Triethoxysilane(ACTES) as coupling agent; the SOD activity of the mimetic enzyme was investigated with IC50 of 0.0041 g·L-1and 0.0012 g·L-1; the CAT activity of the mimetic enzyme modified Schiff base of Methionine was investigated.All products were characterized by IR, TGA, SEM and EDS. Results show that:(1) The mimetic enzyme modified polyamine and contained Mn and Cu have both SOD and CAT activities;(2) The mimetic enzyme modified Schiff base of Salicylaldehyde and contained Mn and Cu have both higher SOD and CAT activities;(3) The mimetic enzyme modified Schiff base of Methionine and contained Mn and Cu have both higher SOD and CAT activities.