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Research Paper|Volume 1, Issue 5|pp 481—489

Chain-breaking antioxidant activity of reduced forms ofmitochondria-targeted quinones, a novel type of geroprotectors

Vitaly A. Roginsky1,2, Vadim N. Tashlitsky2,3, Vladimir P. Skulachev2,4
  • 1N. Semenov Instituteof Chemical Physics, Russian Academy of Sciences, 119991 Moscow, RussianFederation
  • 2Centerof Mitoengineering, Moscow State University, 119991, Moscow, RussianFederation
  • 3Chemical Department,Moscow State University, 119991 Moscow, Russian Federation
  • 4A.N.BelozerskyInstitute of Physico-Chemical Biology, Moscow State University, 119991Moscow, Russian Federation
Received: March 6, 2009Accepted: May 11, 2009Published: May 12, 2009
https://doi.org/10.18632/aging.100049

Copyright: © 2009 Roginsky et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Thechain-breaking antioxidant activities of reduced form of novel type ofgeroprotectors, mitochondria-targeted quinones (QH2) havequantitatively been measured for the first time. To this end, the chainperoxidation of methyl linoleate (ML) in Triton micelles was used as akinetic testing model. The studied QH2 were lipophilictriphenylphosphonium cations conjugated by an aliphatic linker to anantioxidant, i.e. a ubiquinol moiety (MitoQH2) or plastoquinolmoiety (SkQH2). The antioxidant activity was characterized bythe rate constant k1 for the reaction between QH2 andthe lipid peroxyl radical (LO2·) originatedfrom ML: QH2 + LO2· → HQ· + LOOH. Allthe tested QH2 displayed a pronounced antioxidant activity. Theoxidized forms of the same compounds did not inhibit ML peroxidation. Thevalue of k1 for SkQH2 far exceeded k1 forMitoQH2. For the biologically active geroprotectors SkQ1H2,the k1 value found to be as high as 2.2 × 105 M-1s-1,whereas for MitoQH2, it was 0.58 × 105 M-1s-1. The kineticbehavior of QH2 suggested that SkQ1H2 can rathereasily diffuse through lipid-water microheterogeneous systems.