Russian Journal of Electrochemistry

, Volume 36, Issue 7, pp 767–772 | Cite as

Redox properties of naturally occurring naphthoquinones: Vitamin K2(20) and lapachol

  • S. A. Petrova
  • O. S. Ksenzhek
  • M. V. Koiodyazhnyi


Redox properties of two naturally occurring naphthoquinones, vitamin K2(20) and lapochol, are examined by thin-layer voltammetry on a pyrolytic graphite electrode. The pH-potential diagrams of these compounds are plotted. In aqueous solutions, the quinones are shown to exist each in five forms. Thermodynamic parameters for all redox and acid-base equilibria between conjugated forms are determined. In contrast to lapachol, vitamin K2(20) forms, during its reduction, a large amount of stable semiquinone in a wide pH interval


Quinone Redox Property Naphthoquinones Pyrolytic Graphite Electrode Lapachol 
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Copyright information

© MAIK “Nauka/Interperiodica” 2000

Authors and Affiliations

  • S. A. Petrova
    • 1
  • O. S. Ksenzhek
    • 1
  • M. V. Koiodyazhnyi
    • 1
  1. 1.Ukrainian State University of Chemical TechnologyDnepropetrovskUkraine

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