SIGNIFICANCE OF BENZENE RINGS IN PROTEIN BINDING OF PROMAZINE AND CHLORPROMAZINE

The different binding ability of bovine serum albumin for promazine and chlorpromazine suggested that the benzene rings of the phenothiazine nucleus are involved in the protein binding. Simple aromatic substances such as benzoic acid, salicylic acid, acetylsalicyclic acid and nicotinic acid were able to displace the phenothiazine derivates from their binding to bovine serum albumin. On the other hand alicyclic compounds such as cyclohexylamine and tranexamic acid had no displacing activity. From these results it was concluded that hydrophobic interactions between the phenothiazine derivatives and the protein are mediated by the benzene rings within the phenothiazine molecules. © 1969 Springer-Verlag.