novel analogues of n-piperazinyl fluoroquinolones were prepared and evaluated against a panel of gram-positive and gram-negative bacteria, to study the effect of introducing bulky anthracene and phenanthrene moieties on the antibacterial effects of norfloxacin, ciprofloxacin and gatifloxacin. although most of the novel synthesized compounds had lower antibacterial effects, some derivatives show...

PURPOSE The prokaryotic type II topoisomerases (DNA gyrase and topoisomerase IV) and the eukaryotic type II topoisomerases represent the cellular targets for quinolone antibacterial agents and a wide variety of anticancer drugs, respectively. In view of the mechanistic similarities and sequence homologies exhibited by the two enzymes, tentative efforts to selectively shift from an antibacterial...

Introduction: Fluoroquinolones are potent inhibitors of bacterial topoisomerase II. They can also inhibit eukaryotic topoisomerase, and may confer antitumoral properties. Method: In this study the antitumoral activity of a new series of N-substituted piperazinylfluoroquinolones against a panel of human tumor cell lines was determined by MTT assays. Results: Among the tested compounds N-[2- (5-b...

Abstract: A series of N-[2-(8-metoxy-2H-chromen-2-one)ethyl] piperazinyl quinolones containing a carbonyl related functional groups (oxo or oxyimino) on the ethyl spacer of coumarin and piperazin rings was synthesized and studied for their antibacterial and antifungal activities . The synthesis of compounds (6a-6l) was achieved through the versatile and efficient synthetic route that involved r...

Abstract: A series of N-[2-(8-metoxy-2H-chromen-2-one)ethyl] piperazinyl quinolones containing a carbonyl related functional groups (oxo or oxyimino) on the ethyl spacer of coumarin and piperazin rings was synthesized and studied for their antibacterial and antifungal activities . The synthesis of compounds (6a-6l) was achieved through the versatile and efficient synthetic route that involved r...

quinolones are broad-spectrum antibacterial agents.they have many clinical uses which are increasing.quinolones exert antibacterial activity primarily by inhibiting bacterial DNA gyrase.the inhibition of DNA gyrase by the quinolones are greatly influenced by the nature of the C-7 substituent on the quinolones molecule.substitution of bulky functional groupd is also possible in C-7 position.furt...

The in vitro antimicrobial activity of ciprofloxacin (Bay o 9867) was compared with those of the other new fluorated piperazinyl-substituted quinoline derivatives: norfloxacin, ofloxacin, and pefloxacin, as well as with those of the earlier analogs, nalidixic acid and oxolinic acid. Virtually no resistance against the new fluorated piperazinyl-substituted quinoline derivatives was observed. As ...

  Quinolone antibacterial agents are currently used for the treatment of various bacterial infections. The nature of functional group at the 7 position of the quinolone ring system is known to have strong influence on the spectrum and extent of in vitro antibacterial activity. Accordingly, a series of N-L2- oxo-2-(2- furyl) and N-[2- oxyimino (2- furyl) ethyl] piperazinyl quinolone derivatives...

Quinolones are synthetic broad-spectrum antibiotics with good oral absorption and excellent bioavailability. Due to the chemical functions found on their nucleus (a carboxylic acid function at the 3-position, and in most cases a basic piperazinyl ring (or another N-heterocycle) at the 7-position, and a carbonyl oxygen atom at the 4-position) quinolones bind metal ions forming complexes in which...