There are a variety of chemicals which regulate the functions of bacterial and mitochondrial complex I. Some of

them, such as rotenone and piericidin A, have been indispensablemolecular tools inmechanistic studies on complex

I. A large amount of experimental data characterizing the actions of complex I inhibitors has been accumulatedso far.  aspects

of complex I, but also on drug design targeting this enzyme. This article is part of a Special Issue entitled

Respiratory complex I, edited by Volker Zickermann and Ulrich Brandt.