Redox-active agents

Although zinc itself is not redox-active, some class I enzymes containing zinc in their active sites are known. The most prominent are probably alcohol dehydrogenase and copper-zinc superoxide dismutase (Cu,Zn-SOD). AU have in common that the redox-active agent is another transition-metal ion (copper in Cu,Zn-SOD) or a cofactor such as nicotinamide adenine dinucleotide (NAD+/NADH). The Zn(II) ion affects the redox reaction only in an indirect manner, but is nevCTtheless essential and cannot be regarded simply as a structural factor. 

Crapo, J.D. (2003h). Redox active agents in inflammatory lung injury. Am J Respir Crit Care Med 168, 1027-8. 

Ferrocene-functionalized oligothiophenes are interesting redox functional systems, in which the ferrocene is a donor as well as the oligothiophene backbone, and therefore demonstrate unique redox properties. As examples, structures 2.162 and 2.163 are shown (Chart 1.34) in which either ferrocenes are connected to the termini of the oligothiophene or represent the core for the conjugated co-oligomers [255, 256]. These systems play a role as unique redox-active agents and are described in detail in Chapter 5. 

However, a weakness of these experimental approaehes is that they eannot clearly define the point of moleeular interaetion with the HIF system. For example, redox-active agents that are proposed to affeet the oxygen-sensing meehanism might do so directly, or very indireetly in a way that does not mimie physiological regulation by oxygen. 

Dierks EA, Burslyn JN. The deactivation of soluble guanylyl cyclase by redox-active agents. Arch Biochem Biophys 1998 351 1—7. 

The conducting polymers can make a transition from an initial insulating/seniiconducting state to an electrically conducting state after the chemical treatment with redox active agents and have been increasingly used for optical and bio/gas sensors. However, the problem of stability and its reaction with moieties present in the environment limits the appH-cation of most of the organic materials (Kaushika et al., 2013). 

Mechanistic Studies of Motexafin Gadolinium (Xcytrin ) A Redox Active Agent That Reacts with Electron-Rich Biological Substrates... 

Wu JH, Winn PJ, Ferenczy GG, Reynolds CA (1999) Solute polarization and the design of cobalt complexes as redox-active therapeutic agents. Int J Quant Chem 73(2) 229-236... 

Hartinger, C. G., Jakupec, M. A., Zorbas-Seifried, S., Groessl, M., Egger, A. Bergar, W. KP1019, A New Redox-Active Anticancer Agent - Preclinical Development and Results of a Clinical Phase I Study in Tumor Patients. Chem. Biodiversity, 5, 2140-2155 (2008). 

Because metal ions bind to and modify the reactivity and structure of enzymes and substrates, a wide spectrum of techniques has been developed to examine the nature of metal ions which serve as templates, redox-active cofactors, Lewis acids/bases, ion-complexing agents, etc. 

J.H. Shin, Y.S. Choi, H.J. Lee, S.H. Choi, J. Ha, I.J. Yoon, H. Nam and G.S. Cha, A planar amperometric creatinine biosensor employing an insoluble oxidizing agent for removing redox-active interference, Anal. Chem., 73 (2001) 5965-5971. 

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