Electrochemical behavior of ubiquinone and vitamin K incorporated into n-alkanethiol molecular assemblies on a gold electrode

Electrochemical Studies of Vitamin K1Microdroplets: Electrocatalytic Hydrogen Evolution

“…The reduction process comprises a single broad reduction wave at E takes place at E Ox p 0.4 V. This oxidation wave is broad, but nevertheless there is a post-peak ™shoulder∫ on this wave at E 0.6 V. The observation of single reduction and oxidation peaks in the biphasic system employed herein is in agreement with the results of vitamin K 1 electrochemistry in homogeneous aqueous alcohol solutions by Hart and co-workers [4,11,12] employing carbon electrodes. The broad nature of the signals in Figure 2 is in contrast to that observed in previous systems employing microdroplet-modified electrodes.…”

New insights into the chemistry of Coenzyme Q-0: A voltammetric and spectroscopic study

“…CoQ-0 [21][22][23]. Because the water solubility of CoQ-0 (2,3-dimethoxy-5-methyl-p-benzoquinone) is very good (about 100 mg/L), one can easily perform common voltammetry of CoQ-0 in aqueous solutions.…”

“…Only few studies have been reported which consider the properties of CoQ-0 as an electron acceptor of the superoxide radical or as a model for the quinone site in bacterial photosynthetic reaction center [21][22][23]. In addition to our previous studies on CoQ-1 and CoQ-10, the work presented here significantly contributes to a better understanding of the complex chemistry and redox properties of these biologically important organic compounds, and it also implies potential applications of its derivatives as cation chelators and antioxidants.…”

Lipophilic 1,4-naphthoquinone derivatives: synthesis and redox properties in solution and entrapped in the aqueous cubic liquid-crystalline phase of monoolein

“…The redox activity of physiological molecules like ubiquinone-10 (UQ 10 ) or plastoquinone-9 (PQ 9 ), solubilized in hydroxylic solutions, has been examined (Okamura and Feher, 1992). Various self-assembly methods were used to incorporate ubiquinones or plastoquinones at the interface between water and modified electrodes, either by means of direct adsorption at the electrode surface (Gordillo and Schiffrin, 1994) or by incorporation into alkanethiol monolayer (Takehara et al, 1991) it has been shown that newly synthesized 1,4-naphthoquinones linked via nitrogen atom through the short chain to the terminal sulfanyl group form self-assembled monolayers on gold electrode (Kažemėkaitė et al, 2006). Numerous model membrane systems have been developed for the studying the physicochemical behavior of quinone molecules inside a bilayer (Gennis, 1989).…”