Ex situ Voltammetry and Chronopotentiometry of Doxorubicin at a Pyrolytic Graphite Electrode: Redox and Catalytic Properties and Analytical Applications

Vacek, Jan; Havran, Luděk; Fojta, Miroslav

doi:10.1002/elan.200904646

Cited by 46 publications

(24 citation statements)

References 33 publications

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“…In agreement with data published in 10a, peak O cat height was strongly depressed in the presence of an excess of dsDNA, interacting with DOX to form intercalative complexes (Fig. 3 C).…”

Section: Methodssupporting

confidence: 92%

“…DOX is an antitumor anthracycline antibiotic binding to dsDNA in the intercalative mode, exhibiting well pronounced electrochemistry due to two quinone/hydroquinone redox pairs with redox potentials around +0.5 V (corresponding to a SWV peak denominated here as DOX red , well separated from the peak WLA q red due to WLA see Figure 3 B) and around −0.5 V. The latter redox process is coupled with catalytic reduction of oxygen to hydrogen peroxide, under aerobic conditions giving rise to the peak O cat (Figure 3 B) that was previously used 10a for monitoring of DOX‐dsDNA interactions. Here we used the peak O cat , together with simultaneously measured peak WLA red (using SWV procedure optimized in 10a; these measurements were performed on air. Considerably smaller WLA peak currents, compared to other measurements in this paper, are caused by 10‐fold lower SWV frequency applied in this experiment) for evaluation of competitive binding of WLA and DOX to dsDNA.…”

Section: Methodsmentioning

confidence: 88%

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Electrochemical Activity of Wedelolactone and Probing its Interaction with DNA Using Voltammetry at a Carbon Electrode

et al. 2015

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Wedelolactone (WLA) is ac oumestan derivative (see Figure 1A for formula)f ound in extracts of Wedelia calandulaceae and Eclipta prostrata [1],p lants used in traditional Asian and South American medicine for treatment of septic shock, liver diseases,v iral infections or snake bites [1b,2] [7],m aking it ac andidate for utilization in cancert reatment togetherw ith other coumestans [8]. Recent studieso ft he mechanismso fi ts antiproliferative activity have shown that WLA is ac atalytic inhibitor of topoisomerase IIa and blocks bindingo fD NA topoisomerase IIa to DNA[ 7a, b].T he inhibitory effect of wedelolactone on the topoisomerase IIa activity was dependent on redox conditions,b eing diminished in the presence of reducing agents [7a].I nv itro interactions of WLA with DNAw ere inspected in [7b];r esults of Hoechst 33258 fluorescenceq uenching assay indicated certaine xtent of bindingo fW LA to double-stranded (ds) DNA, while topoisomerase relaxation assayd id not evidence intercalation of WLA into the DNAd ouble helix. Thep resent work is focused on electrochemical properties of WLA at the basal plane pyrolytic graphite electrode (PGE) and utilization of electrochemicalm ethods for studying its interactions with DNA.In cyclic voltammetry,W LA yielded ar eversible pair of peaks around 0.275 V( Figure 1A). Considering the presence of catechol moiety in the WLA molecule (see Inset in Figure 1A)w ea scribed these signals to the ortho-(quinone/hydroquinone) redox system (Scheme1) [9]: Then, the anodic peak WLA ox corresponded to oxidation of the o-hydroquinonem oiety in WLA( marked by red in the WLA formula, Figure 1A)a nd the cathodic peak WLA red to reduction of the quinonef orm. In square-wavev oltammetry (SWV), well-developed signals due to the WLA redoxp rocesses were observed. Figure 1B shows SWV curves measured from negative to Abstract:W edelolactone( WLA) is ap olyphenolic coumestan derivative foundi ne xtracts of plants used in traditional medicine. Duet oi ts cytostatic activity,W LA is one of natural compounds tested as potential anticancer drugs.I nt his work we for the first time studied electrochemical properties of WLAu singc yclic (CV) and square-wave (SWV) voltammetry at the basal-plane pyrolytic graphite electrode.Ar eversible pair of peaks,c orresponding to catechol/o-benzoquinone redox system, was observed usingC Varound 0.275 Vv s. Ag j AgCl j 3MKCl reference electrode.M easurementso fS WV signalo f WLA in the presence of single-or double-stranded DNA suggested aw eak interaction without evident preference for double-strandedD NA.A ni ndirect assay,e mploying electroactive DNAi ntercalatord oxorubicin as competitor,c onfirmed absence of intercalative DNAb indingo f WLA.

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“…In agreement with data published in 10a, peak O cat height was strongly depressed in the presence of an excess of dsDNA, interacting with DOX to form intercalative complexes (Fig. 3 C).…”

Section: Methodssupporting

confidence: 92%

Section: Methodsmentioning

confidence: 88%

Electrochemical Activity of Wedelolactone and Probing its Interaction with DNA Using Voltammetry at a Carbon Electrode

et al. 2015

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“…The same catalytic oxygen reduction of doxorubicin was obtained at a pyrolytic graphite electrode. It was observed that the reduction of oxygen at a bare electrode in electrolyte solution (without Dox) occurs at a potential around À1.0 V [41], while in the presence of Dox, the potential of the oxygen reduction was at À0.5 V [42]. Baring this in mind, a study of the doxorubicin interaction with the GSH modified electrodes investigated in the present work was performed and the results are reported in the followings.…”

Section: Interactions Of Au-gsh Ad Surface With Doxorubicinmentioning

confidence: 75%

Drug–GSH interaction on GSH–Au modified electrodes: A cyclic voltammetry and electrochemical impedance spectroscopy study

Latus

Enache

Volanschi

2011

Journal of Electroanalytical Chemistry

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“…We assume it will be possible to apply the results for study of the interactions of the alkaloids with biopolymers at PGE as we have recently demonstrated in the case of analysis of the interactions of the anti-tumor drug doxorubicin with DNA [28,29]. The results could also contribute to the general theory of the oxidation of isoquinolines and application of the results for sensitive analysis based on adsorptive accumulation on the surface of carbon electrodes.…”

mentioning

confidence: 95%

Oxidation of Protopine at a Pyrolytic Graphite Electrode Using Cyclic and Square‐Wave Voltammetry

et al. 2010

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This paper describes oxidation of the isoquinoline alkaloid, protopine (PR) at a pyrolytic graphite electrode (PGE) using cyclic and square-wave voltammetry. In the alkaline range (pH 7.5-10.5) of a Britton-Robinson (B-R) buffer, a PR oxidation can be observed as a well-developed voltammetric peak around + 0.9 V (vs. Ag j AgCl j 3 M KCl). With increasing pH of the B-R buffer, the PR peak is shifted to less positive potentials. The acquired voltammetric data suggest that PR strongly adsorbs onto the surface of the pyrolytic graphite where it is subjected to irreversible electrochemical oxidation in its uncharged free (tricyclic) base form. The results are discussed in connection with the electrochemical oxidation of other isoquinoline alkaloids and the potential applications of these data. Protopine (PR) is an isoquinoline alkaloid found in plants of the Fumariaceae, Papaveraceae, Berberidaceae, Ranunculaceae and Rutaceae families. As a whole range of in vitro and in vivo biological activities have been proven for PR and other isoquinolines, plants of the above families are incorporated in several phytopreparations for use in human and veterinary medicine (reviewed in [1][2][3][4]). A molecule of PR includes a dibenz[c,g]azecine system with two methylenedioxy groups localized at C-2,3 and C-9,10 (Scheme 1A) [5][6][7]. This structure is further referred to as a free or tricyclic PR base but this uncharged structural form of the alkaloid can only be observed in an alkaline environment (Scheme 1B). In contrast, in acidic solutions, PR occurs in the form of a tetracyclic cation, PR + (Scheme 1C). Reversible interconversion between free base and the tetracyclic form of PR is related to structural change, transannular interaction between N-7 and C-14, in the 10-member ring B of the molecule (marked in Scheme 1A) [8][9][10][11]. This mechanism is shown in detail at the bottom of Scheme 1 in panels B and C.Currently, over twenty alkaloids whose structure is derived from PR are known (see [1,[12][13][14] and citations therein). The electrochemistry of PR, other protopine alkaloids and their synthetic derivatives and metabolites have not been described to date. Only partial information exists on the reduction of selected isoquinolines at mercury and several papers have focused on their oxidation at a glassy carbon electrode (GCE).

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Ex situ Voltammetry and Chronopotentiometry of Doxorubicin at a Pyrolytic Graphite Electrode: Redox and Catalytic Properties and Analytical Applications

Cited by 46 publications

References 33 publications

Electrochemical Activity of Wedelolactone and Probing its Interaction with DNA Using Voltammetry at a Carbon Electrode

Electrochemical Activity of Wedelolactone and Probing its Interaction with DNA Using Voltammetry at a Carbon Electrode

Drug–GSH interaction on GSH–Au modified electrodes: A cyclic voltammetry and electrochemical impedance spectroscopy study

Oxidation of Protopine at a Pyrolytic Graphite Electrode Using Cyclic and Square‐Wave Voltammetry

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