Pharmaceutical compositions containing azo compounds have been used for their bactericidal properties and among the same are those described as heterocyclic sulphonamide azo compounds in U.S. Pat. No. 2,396,145 to Askelof et al. and U.S. Pat. No. 3,681,319 to Lindberg. These patents describe a group of azo compounds which are essentially characterized by the formula: ##STR1## To the first end of the azo linkage is attached a benzene ring having hydroxy substitution in the para position. The second end of the azo linkage is attached to a p-[2-pyridylsulfamoyl]-phenyl group. The compounds thus disclosed in these patents have bactericidal characteristics.
We have unexpectedly found novel azo compounds which also possess similar bactericidal characteristics but whose structures are not characteristic of those of U.S. Pat. Nos. 2,396,145 and 3,681,319.
We have unexpectedly found that 2-[(p-(2-pyridylsulfamoyl)phenyl)azo] hydroxybenzene has useful properties as an anti-bacterial agent and yet this molecule has neither the essential carboxy group present nor is it substitution at the first end of the azo linkage in the essential para positions to the hydroxy group. Further, this ring also contains a hydroxy group substituted in the ortho position to the azo linkage.
Also, we have unexpectedly found that 3-[(p-(2-pyridylsulfamoyl)phenyl)azo] salicylic acid has useful properties as an anti-bacterial agent and also this molecule is not substituted at the first end of the azo linkage in the essential para position to the hydroxy group, but rather it is substituted in the ortho position to the hydroxy group.
Additionally, we have unexpectedly found that 5-[(p-(4-(2-pyridylanilines))-N-phenyl)azo] salicylic acid has useful properties as an anti-bacterial agent and this molecule does not contain the essential sulfamoyl linkage between the 2-pyridyl and phenyl moieties at the second end of the azo linkage. This molecule further contains a p-anilino group between the 2-pyridyl and phenyl moieties.
We have also found that these compounds can be combined with pharmaceutical excipients to form anti-bacterial preparations.