Electrochemical and UV-spectrophotometric study of oxygen and superoxide anion radical interaction with anthraquinone derivatives and their radical anions

Ossowski, Tadeusz; Pipka, Piotr; Liwo, Adam; Jeziorek, Danuta

doi:10.1016/s0013-4686(00)00479-5

Cited by 61 publications

(57 citation statements)

References 29 publications

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“…A pair of 10×10 mm path length quartz cuvettes was used. Simulation of electrochemical data was done to explain the probable mechanism for the reactions using esp24b software developed by Dr. Carlo Nervi [28]. Simulation was carried out in planar geometry and cathodic currents were taken positive.…”

Section: Methodsmentioning

confidence: 99%

Exploration of Electrochemical Intermediates of the Anticancer Drug Doxorubicin Hydrochloride Using Cyclic Voltammetry and Simulation Studies with an Evaluation for Its Interaction with DNA

Guin

Das

2014

International Journal of Electrochemistry

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Electrochemical behavior of the anticancer drug doxorubicin hydrochloride was studied using cyclic voltammetry in aqueous medium using Hepes buffer (pH∼7.4). At this pH, doxorubicin hydrochloride undergoes a reversible two-electron reduction with 1/2 value −665 ± 5 mV (versus Ag/AgCl, saturated KCl). Depending on scan rates, processes were either quasireversible (at low scan rates) or near perfect reversible (at high scan rates). This difference in behavior of doxorubicin hydrochloride with scan rate studied over the same potential range speaks of differences in electron transfer processes in doxorubicin hydrochloride. Attempt was made to identify and understand the species involved using simulation. The information obtained was used to study the interaction of doxorubicin hydrochloride with calf thymus DNA. Cathodic peak current gradually decreased as more calf thymus DNA was added. The decrease in cathodic peak current was used to estimate the interaction of the drug with calf thymus DNA. Nonlinear curve fit analysis was applied to evaluate the intrinsic binding constant and site size of interaction that was compared with previous results on doxorubicin hydrochloride-DNA interaction monitored by cyclic voltammetry or spectroscopic techniques.

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Section: Methodsmentioning

confidence: 99%

Exploration of Electrochemical Intermediates of the Anticancer Drug Doxorubicin Hydrochloride Using Cyclic Voltammetry and Simulation Studies with an Evaluation for Its Interaction with DNA

Guin

Das

2014

International Journal of Electrochemistry

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“…37 On the other hand, non-aqueous aprotic solvents should be better models of membrane environment in which peroxidation processes take place, because both superoxide anion radical and its conjugated acid, the hydroperoxyl radical, are virtually unstable in water and other protic solvents, owing to fast disproportionation. 38 The reported experiments are normally performed under different conditions: supporting electrolyte, ionic strength and mainly different working electrodes. Potentials are frequently quoted without the appropriate reference electrode.…”

Section: Practical Problems In the Correlation: Choice Of Experimentamentioning

confidence: 99%

Some Applications of Electrochemistry in Biomedical Chemistry. Emphasis on the Correlation of Electrochemical and Bioactive Properties

Abreu¹,

Ferraz²,

Goulart³

2002

J. Braz. Chem. Soc.

153

124

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Essa revisão resume alguns dos aspectos mais relevantes na correlação entre processos e parâmetros eletroquímicos e atividades biológicas, relacionadas, principalmente, a doenças tropicais e câncer. Apesar da gama de possibilidades e da complexidade da química celular/tecidual/extracelular, é possível racionalizar o papel da eletroquímica em poucas bases teóricas, principalmente: transferência eletrônica -estresse oxidativo, geração eletroquímica in situ de agentes tóxicos diferentes das espécies oxigenadas reativas, interação com endobióticos, com ênfase particular em alquilação biorredutiva e substituição de endobióticos com função em reações de oxi-redução biológicas. O uso de métodos eletroquímicos para a obtenção de mecanismos de ação de drogas e na análise de eventos celulares é também apresentado. Nessas correlações, métodos e/ou parâmetros eletroquímicos exercem papel relevante, porém, não absoluto.This review summarises some of the more relevant achievements in the correlation between electrochemical processes and parameters and bioactive properties, mainly related to cancer and tropical diseases. Despite the broad range of possibilities and the complexity of cell/tissue/extracell chemistry, it is possible to rationalise the role of electrochemistry in few basic theoretical frameworks, mainly, the one based on electron transfer-oxidative stress and in situ generation of toxic species, other than the reactive oxygen species; interaction with endobiotics, with emphasis on bioreductive alkylation and replacement of endobiotics with function in biological redox reactions. The use of electrochemical methods to obtain relevant informations about drugs' mechanism of action and analysis of cellular events is also presented. Electrochemical methods and/or parameters play essential but not absolute roles.

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“…4 -hydroxyquinones can present hydrogen bonding via the -carbon to the carbonyl function leading to a six-membered ring structure ( Figure 1); the hydroxyl group involved in these structures is usually part of a phenolic function. 5,6 When electron transfer reactions occur, the acidity level of both hydroxy functionalities must be taken in account in front of the stability of the formed semiquinone / dianion intermediaries. These last species are related to the reactivity that hydroxyquinone compounds, as it has been reported in many biological essays, particularly in oxygenquinone interaction studies.…”

Section: Introductionmentioning

confidence: 99%

“…These last species are related to the reactivity that hydroxyquinone compounds, as it has been reported in many biological essays, particularly in oxygenquinone interaction studies. 6 A comparative study of both type of hydroxy substituted quinones is necessary, since some interpretations encountered in the literature tend to use indistinctly both type of compounds to account for equivalent behaviors. 6,7 The present study is developed in an effort to emphasize the differences in reactivity between and -hydroxyquinone moieties, on the basis of the analysis of the energies of transformation and charge transfer kinetics, determined from cyclic voltammetry experiments of representative compounds in aprotic conditions.…”

Section: Introductionmentioning

confidence: 99%

“…6 A comparative study of both type of hydroxy substituted quinones is necessary, since some interpretations encountered in the literature tend to use indistinctly both type of compounds to account for equivalent behaviors. 6,7 The present study is developed in an effort to emphasize the differences in reactivity between and -hydroxyquinone moieties, on the basis of the analysis of the energies of transformation and charge transfer kinetics, determined from cyclic voltammetry experiments of representative compounds in aprotic conditions. The employment of ESR measurement simultaneous to the electrochemical reduction allowed also to obtain structural data from the intermediate semiquinone estructures, and was correlated with the electrochemical data.…”

Section: Introductionmentioning

confidence: 99%

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The role of intramolecular hydrogen bonding in the electrochemical behavior of hydroxy-quinones and in semiquinone stability

Frontana¹,

González²

2005

J. Braz. Chem. Soc.

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O estudo de um grupo selecionado de e -hidroxiquinonas ([ ] 2-hidroxi-1,4-naftoquinona 2HNQ, [ ] 5-hidroxi-1,4-naftoquinona 5HNQ and [ , ]5,8-dihidroxi-1,4-naftoquinona DHNQ) mostrou que ambos os tipos de funcionalidades diferem consideravelmente em termos de reatividade eletroquímica e química, e que essas diferenças também se manifestam na comparação de compostos do mesmo grupo. Os resultados provaram que a energia necessária para reduzir eletroquimicamente as hidroxoquinonas estudadas está relacionada com a estabilidade intramolecular das ligações de hidrogênio (IHBs) e com as reações de acoplamento que ocorrem durante a redução eletroquímica, tal como a seqüência de auto-protonação em 2HNQ. A análise da cinética de transferência de elétron associada com a redução monoeletronica que ocorre para 5HNQ e DHNQ mostraram que os efeitos IHB não afetam a cinética do primeiro processo de redução, mas induzem a grandes mudanças na cinética de segunda transferência eletrônica. Isso sugere que as semiquinonas são quimicamente diferentes dos compostos estudados, o que foi comprovado pela análise da estrutura eletrônica das semiquinonas por espectroscopia ESR. Essa análise parece relacionada com a perda de simetria no radical gerado eletronicamente e induz a valores ks de menor velocidade para a segunda redução de transferência de 5HNQ, comparada com DHNQ.The study of a selected group of and -hydroxyquinones ([ ] 2-hydroxy-1,4-naphthoquinone 2HNQ, [ ] 5-hydroxy-1,4-naphthoquinone 5HNQ and [ , ]5,8-dihydroxy-1,4-naphthoquinone DHNQ) showed that both type of functionalities differ considerably in terms of electrochemical and chemical reactivity, and these differences are also manifest even upon comparison between compounds of the same group. The results proved that the energy needed to electrochemically reduce the studied hydroxyquinones is related both to the stability of intramolecular hydrogen bonds (IHBs) and coupled chemical reactions occurring during their electrochemical reduction such as self-protonation sequences in 2HNQ. The analysis of the electron transfer kinetics associated with the monoelectronic reductions occurring for 5HNQ and DHNQ showed that IHB effects do not affect the kinetics of the first reduction process, but induce great changes in the second electron transfer kinetics. This suggests that semiquinone species are chemically different for the studied compounds, as was corroborated by the analysis of the electronic structure of semiquinone species by ESR spectroscopy. This analysis seems to be related to the loss of symmetry in the electrogenerated radical and induces a lower rate ks value for the second reduction transfer of 5HNQ, compared with DHNQ.

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Electrochemical and UV-spectrophotometric study of oxygen and superoxide anion radical interaction with anthraquinone derivatives and their radical anions

Cited by 61 publications

References 29 publications

Exploration of Electrochemical Intermediates of the Anticancer Drug Doxorubicin Hydrochloride Using Cyclic Voltammetry and Simulation Studies with an Evaluation for Its Interaction with DNA

Exploration of Electrochemical Intermediates of the Anticancer Drug Doxorubicin Hydrochloride Using Cyclic Voltammetry and Simulation Studies with an Evaluation for Its Interaction with DNA

Some Applications of Electrochemistry in Biomedical Chemistry. Emphasis on the Correlation of Electrochemical and Bioactive Properties

The role of intramolecular hydrogen bonding in the electrochemical behavior of hydroxy-quinones and in semiquinone stability

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