[Inhibition of respiration and phosphorylation by some maleimide derivatives]

The inhibitory effect of maleimide and ten its N-substituted mono- and bifunctional derivatives was studied in isolated rat liver mitochondria. It was found that all these compounds blocked protein and non-protein SH-groups and were the potent inhibitors of the respiratory chain. In the inhibitory activity of unsubstituted maleimide its alkylating properties play the dominant role. The introduction of some substitutors in the maleimide molecule lends the properties of hydrophobic inhibitors to these derivatives. A high toxicity of all compound studied was shown in in vivo experiments.