Antibacterial activity of N-(beta-styryl) formamides related to tuberin

A series of para-substituted N-(beta-styryl)formamides, analogues of tuberin (4a), has been prepared and assayed for antibacterial activity. The methylthio, ethoxy, and methyl analogues 4e, 4j, and 4t were about twice as active as tuberin against Mycobacterium phlei. Although tuberin lacks activity against Staphylococcus aureus, several of the analogues described were found to inhibit this organism. The phenyl group of tuberin is not a prerequisite for activity since analogues based on naphthyl or ferrocenyl groups were also active. A quantitative structure-activity relationship further implied that an aromatic group need not be present, suggesting the synthesis of the cyclohexyl and n-amyl analogues which were found to possess high activity.