Free-Radical-Induced Oxidative and Reductive Degradation of Sulfa Drugs in Water:  Absolute Kinetics and Efficiencies of Hydroxyl Radical and Hydrated Electron Reactions

2007 ◽  
Vol 111 (37) ◽  
pp. 9019-9024 ◽  
Author(s):  
Stephen P. Mezyk ◽  
Thomas J. Neubauer ◽  
William J. Cooper ◽  
Julie R. Peller
Keyword(s):  
Free Radical ◽  
Hydroxyl Radical ◽  
Hydrated Electron ◽  
Sulfa Drugs ◽  
Reductive Degradation

Free Radical Chemistry of Disinfection-Byproducts. 1. Kinetics of Hydrated Electron and Hydroxyl Radical Reactions with Halonitromethanes in Water

2006 ◽  
Vol 110 (6) ◽  
pp. 2176-2180 ◽  
Author(s):  
Stephen P. Mezyk ◽  
Teresa Helgeson ◽  
S. Kirkham Cole ◽  
William J. Cooper ◽  
Robert V. Fox ◽  
...  
Keyword(s):  
Free Radical ◽  
Hydroxyl Radical ◽  
Disinfection Byproducts ◽  
Hydrated Electron ◽  
Radical Reactions ◽  
Radical Chemistry ◽  
Free Radical Chemistry ◽  
Kinetics Of

Radiolysis studies on the corrosion inhibitors 1 -hexyn-3-ol, cinnamonitrile, and 1,3-diethyl-2-thiourea

1995 ◽  
Vol 73 (12) ◽  
pp. 2137-2142 ◽  
Author(s):  
A.J. Elliot ◽  
M.P. Chenier ◽  
D.C. Ouellette
Keyword(s):  
Hydrogen Atom ◽  
Hydroxyl Radical ◽  
Temperature Dependence ◽  
Rate Constant ◽  
Rate Constants ◽  
Corrosion Inhibitors ◽  
Hydrated Electron

In this publication we report: (i) the rate constants for reaction of the hydrated electron with 1-hexyn-3-ol ((8.6 ± 0.3) × 108 dm3 mol−1 s−1 at 18 °C), cinnamonitrile ((2.3 ± 0.2) × 1010 dm3 mol−1 s−1 at 20 °C), and 1,3-diethyl-2-thiourea ((3.5 ± 0.3) × 108 dm3 mol−1 s−1 at 22 °C). For cinnamonitrile and diethylthiourea, the temperature dependence up to 200 °C and 150 °C, respectively, is also reported; (ii) the rate constants for the reaction of the hydroxyl radical with 1-hexyn-3-ol ((5.5 ± 0.5) × 109 dm3 mol−1 s−1 at 20 °C), cinnamonitrile ((9.2 ± 0.3) × 109 dm3 mol−1 s−1 at 21 °C), and diethylthiourea ((8.0 ± 0.8) × 108 dm3 mol−1 s−1 at 22 °C). For cinnamonitrile, the temperature dependence up to 200 °C is also reported; (iii) the rate constant for the hydrogen atom reacting with 1-hexyn-3-ol ((4.3 ± 0.4) × 109 dm3 mol−1 s−1 at 20 °C). Keywords: radiolysis, corrosion inhibitors, rate constants.

Evaluation of antioxidant activity of Melothria maderaspatana in vitro

2010 ◽  
Vol 5 (2) ◽  
pp. 224-230 ◽  
Author(s):  
Boobalan Raja ◽  
Kodukkur Pugalendi
Keyword(s):  
Hydrogen Peroxide ◽  
Antioxidant Activity ◽  
Free Radical ◽  
Hydroxyl Radical ◽  
Superoxide Anion ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Free Radical Scavenging ◽  
Melothria Maderaspatana

AbstractIn this study, an aqueous extract of leaves from Melothria maderaspatana was tested for in vitro antioxidant activity. Free radical scavenging assays, such as hydroxyl radical, hydrogen peroxide, superoxide anion radical and 2,2-diphenyl-1-picryl hydrazyl (DPPH), 2,2’-azinobis-(3-ethyl-enzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and reducing power assay, were studied. The extract effectively scavenged hydroxyl radical, hydrogen peroxide and superoxide anion radicals. It also scavenged DPPH and ABTS radicals. Furthermore, it was found to have reducing power. All concentrations of leaf extract exhibited free radical scavenging and antioxidant power, and the preventive effects were in a dose-dependent manner. The antioxidant activities of the above were compared to standard antioxidants such as butylated hydroxytoluene (BHT), ascorbic acid, and α-tocopherol. The results obtained in the present study indicate that the M. maderaspatana extract could be considered a potential source of natural antioxidant.

Free-radical-induced oxidative and reductive degradation of N,N′-diethyl-m-toluamide (DEET): Kinetic studies and degradation pathway

2009 ◽  
Vol 43 (3) ◽  
pp. 635-642 ◽  
Author(s):  
Weihua Song ◽  
William J. Cooper ◽  
Barrie M. Peake ◽  
Stephen P. Mezyk ◽  
Michael G. Nickelsen ◽  
...  
Keyword(s):  
Free Radical ◽  
Kinetic Studies ◽  
Degradation Pathway ◽  
Reductive Degradation

Free-Radical-Induced Oxidative and Reductive Degradation of Fluoroquinolone Pharmaceuticals: Kinetic Studies and Degradation Mechanism

2009 ◽  
Vol 113 (27) ◽  
pp. 7846-7851 ◽  
Author(s):  
Hanoz Santoke ◽  
Weihua Song ◽  
William J. Cooper ◽  
John Greaves ◽  
George E. Miller
Keyword(s):  
Free Radical ◽  
Degradation Mechanism ◽  
Kinetic Studies ◽  
Reductive Degradation
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