Redox reactions of transient species formed during pulse radiolysis of 2-pyridine carboxaldehyde and 2-pyridine methanol in aqueous solutions

The pulse radiolysis of aqueous solutions of selenomethionine has been studied under both neutral and acid conditions and the transient optical absorption spectra have been observed. The reactivities of both eāq and OH radicals have been measured as well as the formation and the decay kinetics of the transient species.

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One-electron oxidation of ergothioneine and analogues investigated by pulse radiolysis: redox reaction involving ergothioneine and vitamin C

Biochemical Journal ◽

10.1042/bj3150625 ◽

1996 ◽

Vol 315 (2) ◽

pp. 625-629 ◽

Cited By ~ 51

Author(s):

Klaus-Dieter ASMUS ◽

René V. BENSASSON ◽

Jean-Luc BERNIER ◽

Raymond HOUSSIN ◽

Edward J. LAND

Keyword(s):

Oxidative Stress ◽

Vitamin E ◽

Vitamin C ◽

Redox Reaction ◽

Redox Reactions ◽

Pulse Radiolysis ◽

Antioxidant Properties ◽

Transient Species ◽

Rapid Reduction ◽

The One

Redox reactions of endogenous and exogenous sulphur-containing compounds are involved in protection against oxidative damage arising from the incidence and/or treatment of many diseases, including cancer. We have investigated, via pulse radiolysis, the one-electron oxidation of ergothioneine, a molecule with antioxidant properties which is detected at millimolar concentrations in certain tissues and fluids subject to oxidative stress, including erythrocytes and plasma. The spectrum of the transient species, assigned to the product of one-electron oxidation, observed after reaction of ergothioneine with the oxidizing radicals OH•, N3• and CCl3O2• has a maximum absorption at 520 nm and is very similar to that obtained by oxidation of analogous molecules such as 2-mercaptoimidazole, 1-methyl-2-mercaptoimidazole, S-methyl- and S,N-dimethyl-ergothioneine. In the presence of vitamin C, the oxidized form of ergothioneine is repaired by a rapid reduction (k = 6.3×108 M-1·s-1) producing ascorbyl radicals. This co-operative interaction between ergothionine and ascorbate, similar to that previously observed between vitamin E and ascorbate, may contribute to essential biological redox protection.

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Nature of the transient species formed in pulse radiolysis of n-allylthiourea in aqueous solutions

Research on Chemical Intermediates ◽

10.1163/156856706775012996 ◽

2006 ◽

Vol 32 (1) ◽

pp. 83-94 ◽

Cited By ~ 2

Author(s):

D B Naik ◽

T Mukherjee

Keyword(s):

Aqueous Solutions ◽

Pulse Radiolysis ◽

Transient Species

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A Pulse Radiolysis Study of the Reaction of the Sulfate Radical Ion in Aqueous Solutions of Styrene

Australian Journal of Chemistry ◽

10.1071/ch9792611 ◽

1979 ◽

Vol 32 (12) ◽

pp. 2611 ◽

Cited By ~ 9

Author(s):

NA McAskill ◽

DF Sangster

Keyword(s):

Aqueous Solutions ◽

Absorption Spectra ◽

Pulse Radiolysis ◽

Cation Radical ◽

Ultraviolet Absorption ◽

Sulfate Radical ◽

Transient Species ◽

Acetonitrile Solutions ◽

Type Radical

The ultraviolet absorption spectra of the transient species formed during the pulse radiolysis of styrene and peroxydisulfate (S2O82)solutions showed that a benzyl-type radical was formed from styrene and the SO4- radical. The effect of adding Cl- was also studied. These results are in conflict with the claim1 that a phenylethyl radical was formed from SO4-' via the styrene cation radical. That study was made on acetonitrile solutions of styrene, S2O82-, CuCl2 and LiCl and the present results suggest that up to 70% of the SO4-' radicals may have been converted into Cl2-1 radical which then reacted with styrene.

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