Plant Physiol. email content delivery
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Plant Physiology 80:500-504 (1986)
© 1986 American Society of Plant Biologists

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Ravanel, P.
Right arrow Articles by Douce, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ravanel, P.
Right arrow Articles by Douce, R.
Agricola
Right arrow Articles by Ravanel, P.
Right arrow Articles by Douce, R.
Articles

Platanetin: A Potent Natural Uncoupler and Inhibitor of the Exogenous NADH Dehydrogenase in Intact Plant Mitochondria

Patrick Ravanel1, Michel Tissut and Roland Douce

Laboratoire de Physiologie cellulaire végétale, UA du CNRS 576, Université I de Grenoble, B.P. 68, 38 402 Saint Martin D'Heres Cedex, France

Platanetin is a 3,5,7,8-tetrahydroxy, 6-isoprenyl flavone isolated from the bud scales of the plane tree (Platanus acerifolia Willd.). Its effects on the oxidative activities of isolated potato and mung bean mitochondria have been studied. The most noticeable effect is the selective inhibitory effect of this compound on the activity of the external NADH dehydrogenase of the inner membrane. A 50% inhibition of the NADH oxidation rate is obtained at a 2 micromolar concentration. This activity is probably due to the flavonoid structure and the high lipophilicity of platanetin associated with the presence of the isoprenyl chain. Another important effect of platanetin is its uncoupling activity on oxidative phosphorylation. The presence of easily dissociable hydroxyl groups and the high lipophilicity of platanetin allow a potent H+ transfer through the mitochondrial inner membrane. This uncoupling activity is comparable to that of carbonyl cyanide p-trifluoromethoxyphenylhydrazone. Platanetin is therefore the most active natural uncoupler known at the present time (full uncoupling at 2 micromolar with succinate as substrate). At higher concentrations (10 micromolar and more), platanetin can transfer electrons from the mitochondrial inner membrane to O2; the branching point of this KCN-salicylhydroxamic acid insensitive platanetin dependent oxidative pathway is located at the level of flavoproteins, no transfer occurring when succinate is the substrate. The redox properties of platanetin are in accord with such an activity.

1 Permanent address: Laboratoire de Pharmacognosie, Université I de Grenoble, Domaine de La Merci, 38 700 La Tronche, France.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ASPB Publications PLANT PHYSIOLOGY THE PLANT CELL
Copyright © 1986 by the American Society of Plant Biologists