Design, synthesis and biological evaluation of 3-(4-halophenyl)-3-oxopropanal and their derivatives as novel antibacterial agents.

In continuing our program aimed to search for potent drugs for bacterial infections, a series of 3-(4-halophenyl)-3-oxopropanal and their derivatives were designed, synthesized and their antibacterial activities in vitro against both Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa were evaluated. Compounds 7, 8, 13-16, 21 and 22 had moderate antibacterial activities against Staphylococcus aureus (minimal inhibitory concentration (MIC) <16 microg/ml), suggesting that the introduction of mono-methoxyamine or ethoxyamine moiety might play an important role in determining the potent antibacterial activities. Furthermore, the antibacterial activities of select compounds 7, 15 and 16 against the clinically important pathogenic bacteria-methicillin-resistant Staphylococcus aureus (MRSA) were also investigated. Results showed that these compounds exhibited more potent activities than the well-known antibacterial agents Houttuynin and Levofloxacin.