scholarly journals Kinetics of the Reactions of Hydroxyl Radicals with Furan and Its Alkylated Derivatives 2-Methyl Furan and 2,5-Dimethyl Furan

2020 ◽  
Vol 124 (37) ◽  
pp. 7416-7426
Author(s):  
Charlotte A. Whelan ◽  
Julia Eble ◽  
Zara S. Mir ◽  
Mark A. Blitz ◽  
Paul W. Seakins ◽  
...  
Keyword(s):  
Hydroxyl Radicals ◽  
Kinetics Of

The Kinetics of Hydroxyl-Radical-Induced Strand Breakage of Hyaluronic Acid. A Pulse Radiolysis Study Using Conductometry and Laser-Light-Scattering

1990 ◽  
Vol 45 (9-10) ◽  
pp. 1031-1043 ◽  
Author(s):  
David J. Deeble ◽  
Eberhard Bothe ◽  
Heinz-Peter Schuchmann ◽  
Barry J. Parsons ◽  
Glyn O. Phillips ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Free Radical ◽  
Light Scattering ◽  
Dose Rate ◽  
Hydroxyl Radicals ◽  
Laser Light ◽  
Laser Light Scattering ◽  
Half Time ◽  
Strand Breakage ◽  
Kinetics Of

Abstract Hydroxyl radicals were generated radiolytically in N2O -and N2O / O2(4: 1)-saturated aqueous solutions of hyaluronic acid. The hydroxyl radicals react rapidly with hyaluronic acid mainly by abstracting carbon-bound H atom s. As a consequence of subsequent free-radical reactions, chain breakage occurs the kinetics of which has been followed using the pulse radio­ lysis technique. In the absence of oxygen, strand breakage was followed by the change in conductivity in­ duced by the release of cationic counterions condensed at the surface of hyaluronic acid which is a polyanion consisting of subunits of glucuronic acid alternating with N-acetyl-glucosamine. It appears that strand breakage is not due to one single first-order process, however, the con ­ tributions of the different com ponents cannot be adequately resolved. At pH7 the overall half-life is 1.4 ms, in both acid and basic solutions the rate of free-radical induced strand breakage is accelerated (at pH 4.8, t1/2 = 0.6 ms; at pH 10, t1/2 = 0.18 ms). In the absence of oxygen there is no effect of dose rate on the kinetics of strand breakage. In the presence of oxygen in addition to conductom etric detection, strand breakage was also followed by changes in low-angle laser light-scattering. These two techniques are complementary in that in this system the conductometry requires high doses per pulse while the light-scat­ tering technique is best operated in the low -dose range. In the presence of oxygen a pro­ nounced dose-rate effect is observed, e.g. at pH 9.7 after a dose of 9.4 Gy the overall half-time is approx. 0.5 s, while after a dose of 6.6 Gy the half-time is approx. 0.23 s. Both the yield and the rate of strand breakage increase with increasing pH, e.g. at pH 7 G(strand breaks) = 0.7 × 10-7 mol J-1 and at pH 10.4, 4.8 × 10-7 mol J-7. The radiolytic yields of CO2, H2O2, organic hydroperoxides, O2·- and oxygen consum ption have been determined in y-irradiated N2O/ 0 2(4: 1)-saturated solutions of both hyaluronic acid and β-cyclodextrin.

ChemInform Abstract: KINETICS OF THE REACTIONS OF HYDROXYL RADICALS WITH N-ALKANES AT 299 .+-. 2 K

1982 ◽  
Vol 13 (43) ◽  
Author(s):  
R. ATKINSON ◽  
S. M. ASCHMANN ◽  
W. P. L. CARTER ◽  
A. M. WINER ◽  
J. N. JUN. PITTS
Keyword(s):  
Hydroxyl Radicals ◽  
Kinetics Of

Real time structural kinetics of RNA polymerase promoter recognition studied by fast footprinting with X-ray generated hydroxyl radicals.

2005 ◽  
Vol 2005 (Spring) ◽  
Author(s):  
Anastasia Rogozina ◽  
Ferdinand Walther ◽  
Bianca Sclavi ◽  
Evgeny Zaychikov ◽  
Malcolm Buckle ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Real Time ◽  
Hydroxyl Radicals ◽  
X Ray ◽  
Promoter Recognition ◽  
Rna Polymerase Promoter ◽  
Kinetics Of

Theoretical Study of the Kinetics of the Hydrogen Abstraction from Methanol. 3. Reaction of Methanol with Hydrogen Atom, Methyl, and Hydroxyl Radicals

1999 ◽  
Vol 103 (19) ◽  
pp. 3750-3765 ◽  
Author(s):  
Jerzy T. Jodkowski ◽  
Marie-Thérèse Rayez ◽  
Jean-Claude Rayez ◽  
Tibor Bérces ◽  
Sándor Dóbé
Keyword(s):  
Hydrogen Atom ◽  
Hydroxyl Radicals ◽  
Theoretical Study ◽  
Hydrogen Abstraction ◽  
Kinetics Of
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