Synthesis Of Novel1,3-diaryl Pyrazol Derivatives Bearing Rhodanine Moieties As Potential Antibacterial Agents

Around the world, the diseases of bacterial infections have been some of most deadly diseases, and the treatment of bacterial infections still remains an important and challenging therapeutic problem because of factors that include emerging infectious diseases and the increasing number of multi-drug resistant microbial pathogens. Thus development of novel antimicrobial drugs is still in demand. In this paper, we know pyrazole derivatives are a class of nitrogen-containing heterocyclic compounds with a variety of activities, including bactericidal, anti-inflammatory, analgesic, anti-virus. and pyrazole ring is replaced multi-faceted, which lead to a very broad research in the drug development. Rhodanine derivatives also have a class of heterocyclic compounds with important physiological activity. According to the merging principle of drug design, put the pyrazole ring and rhodanine steucture together to design two series of39target compounds. All target compounds structures were determined by analytical and spectral (1H NMR, MS,13C NMR, FTIR) methods, and were evaluated for their antibacterial activity. In the first series of24target compounds (1,3-diaryl pyrazole derivatives bearing rhodanine-3-fatty acid moieties), most of compounds have shown a certain degree of antibacterial activity against Gram-negative bacteria,27(IC50=2μg/mL) exhibited stronger antibacterial activity against the methicillin-resistant Staphylococcus aureus (MRSA) than the controls (norfloxacin and oxacillin). In the second series of15target compounds (1,3-diaryl pyrazol with phenylalanine-derived rhodanine), all the compounds have shown great antibacterial activity against Gram-negative bacteria, compounds6b、6d、6g、6h、6j and6m with MIC of1μg/mL were stronger than the standard drug against MRSA and QRSA. None of the39compounds showed any activity against Gram-negative bacteria in64μg/mL.