A series of para-substituted N-(P-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 ...