Potential salicylamide antiplaque agents: in vitro antibacterial activity against Actinomyces viscosus

A series of 55 salicylamides, including 3,5-dibromo-, 5-n-alkyl-, and 5-n-acylsalicyloyl derivatives of various anilines, heterocyclic amines, benzylamines, and alkylamines, was synthesized and evaluated for in vitro antibacterial activity against Actinomyces viscosus, an adherent oral microorganism implicated in periodontal disease. The in vitro minimum inhibitory concentrations of 15 4'-bromosalicylanilides were found to correlate (r = 0.92) with estimated log D values. Several nonhalogenated salicylanilides, such as 5-n-hexyl- (40) and 5-n-decanoyl-4'-nitrosalicylanilide (47), were found to exhibit higher levels of in vitro antibacterial activity against a number of Actinomycetes than did tribromsalan (1) or fluorophene (2).