Synthesis and antibacterial activity of N-[5-(chlorobenzylthio)-1,3,4-thiadiazol-2-yl] piperazinyl quinolone derivatives.

A series of N-[5-(chlorobenzylthio)-1,3,4-thiadiazol-2-yl] piperazinyl quinolone derivatives (4a-I) have been synthesized by reaction of piperazinyl quinolones with 5-chloro-2-(chlorobenzylthio)-1,3,4-thiadiazoles. Their structures were confirmed by elemental analysis, IR and NMR spectra. The antibacterial activities of 4a-I against a variety of Gram-positive and Gram-negative bacteria were determined.

Synthesis and antibacterial activity of levofloxacin derivatives with certain bulky residues on piperazine ring.

A number of levofloxacin analogues carrying a 2-aryl-2-oxoethyl or a 2-aryl-2-oxyiminoethyl moiety attached to the piperazine ring at C-10 position have been prepared and evaluated as antibacterial agents against a series of Gram-positive and Gram-negative bacteria. Some of them exhibited significant inhibitory activity against Gram-positive bacteria.

Synthesis and antibacterial activity of nitroaryl thiadiazole-levofloxacin hybrids.

Novel levofloxacin-containing hybrids carrying a 5-(nitroaryl)-1,3,4-thiadiazol-2-yl group were synthesized and evaluated in vitro against Gram-positive and Gram-negative bacteria. Preliminary data indicated that levofloxacin-nitrofuran and levofloxacin-nitroimidazole hybrids have a potent activity against Gram-positive organisms with enhanced anti-staphylococcal activity compared with the parent quinolone (N-desmethyl levofloxacin).