Determination of the hydroperoxil group level in polyethylene glycols using a novel mimic enzyme Fe(III)-Mn(II)(HNAPTS)2.
Two kinds of Schiff base metal complexes of 2-hydroxy-1-naphthaldehyde-2-amino-5-phenylthiazole (HANPTS), Mn(II)(HNAPTS)(2) and Fe(III)(HNAPTS)(2), were synthesized and used to mimic the active group of horseradish peroxidase (HRP). The catalytic characteristics of the mimic enzymes in the oxidation reaction of ascorbic acid (AsA) with the OOH group in polyethylene glycols (PEGs) have been studied by a spectrophotometric method. Fe(III) has remarkable coordinated catalysis to Mn(II)(HNAPTS)(2); as a result, the catalytic ability of Fe(III)-Mn(II)(HNAPTS)(2) is 75% of that of HRP. The possible mechanism of the reaction was discussed. The linear relationship between deltaA(265)(AsA) and OOH group concentrations was in the range of 1.5 x 10(-6) to 9.0 x 10(-4) mol/L. The proposed method was successfully applied to the determination of the OOH group level in different molecular weight PEGs.
Tang
Bo
B
College of Chemistry, Chemical Engineering and Material Science, Shandong Normal University, Jinan 250014, Shandong Province, China. tangb@sdnu.edu.cn
Cui
Guanwei
G
Du
Ming
M
Chen
Zhenzhen
Z
Wang
Yan
Y
Wang
Hongjian
H
D001205:Ascorbic Acid / Q000737:chemistry; D001665:Binding Sites; D002384:Catalysis; D005290:Ferric Compounds / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000032:analysis*; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D011092:Polyethylene Glycols / Q000737:chemistry*; D012545:Schiff Bases
C473512:2-hydroxy-1-naphthaldehyde-2-amino-5-phenylthiazole Fe(III); C473511:2-hydroxy-1-naphthaldehyde-2-amino-5-phenylthiazole manganese; D005290:Ferric Compounds; D009942:Organometallic Compounds; D012545:Schiff Bases; D011092:Polyethylene Glycols; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D001205:Ascorbic Acid