Antioxidant activity of Mn-salophen complex and its effects on antioxidant enzymes in Escherichia coli

• Main Author: Liu, Zheng-Xian
• Other Authors: Biochemistry and Anaerobic Microbiology
• Format: Others
• Language: en
• Published: Virginia Tech 2014
• Subjects: LD5655.V856 1994.L597; Antioxidants; Escherichia coli > Physiology; Superoxide dismutase
• Online Access: http://hdl.handle.net/10919/40046; http://scholar.lib.vt.edu/theses/available/etd-10202005-102838/

Mn-salophen complex with superoxide-scavenging activity was prepared from manganese(III) acetate dihydrate and salophen in ethanol. Visible absorption spectrum of the red-brown solution exhibited a broad absorption band at 430 - 450 nm with two shoulders between 500 and 600 nm which were absent with either salophen or manganic acetate alone. Titration of salophen with manganese(III) was consistent with a 1:1 Mn to salophen stoichiometry of the complex based on changes in the absorbance at 500 nm or of superoxide scavenging activity. The SOD-like activity of the complex in the xanthine-xanthine oxidase/cytochrome <i>c</i> assay was 1450 units/mg salophen. The SOD activity of the complex was suppressed 50% in the presence of EDTA (1 mM), but was not altered in the presence of bovine serum albumin (1 mg/ml) or crude protein extract of <i>E. coli</i> QC779 <i>sodA sodB</i> (1 mg/ml). <i>E. coli</i> QC779 <i>sodA sodB</i> grew scantily after an 8 hour lag phase in aerobic M63 glucose minimal medium. === Ph. D.