Subject: Coenzyme Q-0 Voltammetry EPR Hydroxyl benzoquinones Antioxidants Calcium binding
Year: 2016
Type: Article
Title: New insights into the chemistry of Coenzyme Q-0: A voltammetric and spectroscopic study
Author: Gulaboski, Rubin
Author: Bogeski, Ivan
Author: Kokoskarova, Pavlinka
Author: Haeri, Haleh H
Author: Mitrev, Sasa
Author: Stefova, Marina
Author: Stanoeva, Jasmina Petreska
Author: Markovski, Velo
Author: Mirčeski, Valentin
Author: Hoth, Markus
Author: Kappl, Reinhard
Abstract: Coenzyme Q-0 (CoQ-0) is the only Coenzyme Q lacking an isoprenoid group on the quinoid ring, a feature important for its physico-chemical properties. Here, the redox behavior of CoQ-0 in buffered and non-buffered aqueous media was examined. In buffered aqueous media CoQ-0 redox chemistry can be described by a 2-electron-2-proton redox scheme, characteristic for all benzoquinones. In non-buffered media the number of electrons involved in the electrode reaction of CoQ-0 is still 2; however, the number of protons involved varies between 0 and 2. This results in two additional voltammetric signals, attributed to 2-electrons-1H(+) and 2-electrons-0H(+) redox processes, in which mono- and di-anionic compounds of CoQ-0 are formed. In addition, CoQ-0 exhibits a complex chemistry in strong alkaline environment. The reaction of CoQ-0 and OH(-) anions generates several hydroxyl derivatives as products. Their structures were identified with HPLC/MS. The prevailing radical reaction mechanism was analyzed by electron paramagnetic resonance spectroscopy. The hydroxyl derivatives of CoQ-0 have a strong antioxidative potential and form stable complexes with Ca(2+) ions. In summary, our results allow mechanistic insights into the redox properties of CoQ-0 and its hydroxylated derivatives and provide hints on possible applications.
Publisher: Elsevier BV
Relation: Bioelectrochemistry (Amsterdam, Netherlands)
Identifier: oai:repository.ukim.mk:20.500.12188/1619
Identifier: http://hdl.handle.net/20.500.12188/1619Identifier: 10.1016/j.bioelechem.2016.05.008
Identifier: https://api.elsevier.com/content/article/PII:S156753941630069X?httpAccept=text/plainIdentifier: https://api.elsevier.com/content/article/PII:S156753941630069X?httpAccept=text/xmlIdentifier: 111
