Reduction of Methylene Blue by Dihydro-compounds, Catalyzed by Aliphatic Amines, and the Reaction of Methylene Blue with Aliphatic Amines

Abstract

Methylene Blue may be regarded as a model compound of flavin co-enzymes, and its reactions in solution are interesting from a biochemical viewpoint. The reduction of Methylene Blue by dihydro-compounds, catalyzed by aliphatic amines, has been studied, and the reaction of Methylene Blue with the aliphatic amines was also investigated to give some information about the semiquinone radicals from Methylene Blue related to flavin co-enzymes. The reactions were carried out in the absence of air at 20 ± 1°C in 1,2-dichloroethane. It was consequently found that the reduction of Methylene Blue by dihydro-compounds was accelerated by the addition of aliphatic amines, and the semiquinone radical of Methylene Blue was formed as an intermediate in the reaction between Methylene Blue and the aliphatic amines.