Although a number of drugs are available in the market, thrust for discovery of new antimicrobial drugs with better pharmacokinetic profile, and lesser toxicity has become necessary in the field of medicinal chemistry due to fast development of microbial resistance towards the existing molecules. The 2(1H) quinolinone, often referred to as carbostyril moiety, is an important structural unit present in many biologically active molecules. Quinolone antibiotics have gained wide acceptance for the treatment of various bacterial infections. Their mode of action is believed to involve inhibition of bacterial DNA gyrase, an enzyme essential for DNA replication. Many natural and synthetic products containing heterocyclic rings such as pyrazoles, pyrazolones, and isoxazolidines and pyrazolidinediones were reported to possess varied pharmacological activities. Research on 2-quinolone and pyrazolidine 3,5-dione and their synthetic analogs have revealed to possess various pharmacological activities along with wide range of antimicrobial activity. It is our interest to synthesize some new 2-quinolones containing pyrazolidinedione moiety and evaluate their antimicrobial activity.
