The in vitro inhibitory effects of quinolones on the bacterial DNA gyrase of Escherichia coli KL-16 and topoisomerase II of fetal calf thymus were compared. All the quinolones tested required higher concentrations to inhibit the topoisomerase II than to inhibit the DNA gyrase, and no correlation existed among their inhibitory activities against both enzymes. However, there was a large differenc...

Diels-Alder cycloadditions of 2(1H)-quinolones having an electron-withdrawing group at the 3-position with alkyl- and silyloxy-1,3-butadienes (2a,b) were carried out to give phenanthridones richly functionalized regio- or stereoselectively under conditions of atmospheric and high pressure. Furthermore, regioselectivity and chemoselectivity of 3-substituted 2(1H)-quinolones to 2a, b were examine...

3-Substituted 2-quinolones are obtained via a novel, metal-free transannulation reaction of 2-substituted indoles with 2-nitroalkenes in polyphosphoric acid. The reaction can be used in conjunction with the Fisher indole synthesis offering a practical three-component heteroannulation methodology to produce 2-quinolones from arylhydrazines, 2-nitroalkenes and acetophenone.

Diels-Alder reactions of 2(1H)-quinolones having an electron-withdrawing group at the 4-position with 1,3-butadiene derivatives were carried out to give the phenanthridones richly functionalized under the conditions of atmospheric and high pressure. Furthermore, the reactivities of 4-substituted 2(1H)-quinolones acting as a dienophile were examined using MO calculation.

quinolones are a very important family of antibacterial agents that are widely prescribed for the treatment of infections in humans. since their discovery in the early 1960s, the quinolone group of antibacterials has generated considerable clinical and scientific interest. two major groups of compounds have been developed from the basic molecule: quinolones and naphthyridones. the 4-pyridone-3-...

We have cloned the DNA gyrase and topoisomerase IV genes of Enterococcus faecalis to examine the actions of quinolones against E. faecalis genetically and enzymatically. We first generated levofloxacin-resistant mutants of E. faecalis by stepwise selection with increasing drug concentrations and analyzed the quinolone resistance-determining regions of gyrA and parC from the resistant mutants. I...

BACKGROUND Sulfa antibiotics, such as a combination product of trimethoprim and sulfamethoxazole, have traditionally been the drugs of choice for urinary tract infections (UTIs) and remained the most common treatment as recently as a decade ago. However, increasing sulfa resistance among Escherichia coli may have led to changes in prescribing practices. METHODS We used the 2000-2002 National ...

We report two cases of tendon rupture associated with ciprofloxacin. One patient had a complete rupture of an Achilles tendon 6 months after taking the medication. The other case involved a partial rupture of the subscapularis tendon. Both ruptures occurred with minimal mechanical stress on the tendons, suggesting that the fluoroquinolone increased the susceptibility to rupture. We also review ...

Brain interstitial fluid (ISF) concentrations, which regulate the toxicodynamic effect of quinolone antimicrobial agents (quinolones) in the central nervous system, have been determined for norfloxacin, ofloxacin, fleroxacin, and pefloxacin using a quantitative brain microdialysis technique. Steady-state brain ISF concentrations of the quinolones were 7-30 times lower than the unbound serum con...