- Novel ofloxacin derivatives: Synthesis, antimycobacterial and toxicological evaluation
-
Thirty novel 9-fluoro-2,3-dihydro-8,10-(mono/di-sub)-3-methyl-8-nitro-7-oxo-7H-[1,4]oxazino[2,3,4-ij]quinoline-6-carboxylic acids were synthesized from 2,3,4,5-tetrafluoro benzoic acid and evaluated for in vitro and in vivo antimycobacterial activities against Mycobacterium tuberculosis H37Rv (MTB), multi-drug resistant Mycobacterium tuberculosis (MDR-TB), and Mycobacterium smegmatis (MC2) and also tested for the ability to inhibit the supercoiling activity of DNA gyrase from mycobacteria. Among the synthesized compounds, 10-[2-carboxy-5,6-dihydroimidazo[1,2-a]pyrazin-7(8H)-yl]-9-fluoro-2,3-dihydro-3-methyl-8-nitro-7-oxo-7H-[1,4]oxazino[2,3,4-ij]quinoline-6-carboxylic acid was found to be the most active compound in vitro with MIC99 of 0.19 μM and 0.09 μM against MTB and MTR-TB, respectively. In the in vivo animal model also the same compound decreased the bacterial load in lung and spleen tissues with 1.91 and 2.91 - log 10 protections, respectively, at the dose of 50 mg/kg body weight. Compound 10-[(4-((4-chlorophenyl)(phenyl)methyl)piperazin-1-yl)]-9-fluoro-2,3-dihydro-3-methyl-8-nitro-7-oxo-7H-[1,4]oxazino[2,3,4-ij]quinoline-6-carboxylic acid was found to be the most active in the inhibition of the supercoiling activity of DNA gyrase with an IC50 of 10.0 μg/mL. The results demonstrate the potential and importance of developing new oxazino quinolone derivatives against mycobacterial infections.
- Dinakaran, Murugesan,Senthilkumar, Palaniappan,Yogeeswari, Perumal,China, Arnab,Nagaraja, Valakunja,Sriram, Dharmarajan
-
p. 1229 - 1236
(2008/09/20)
-
- AN IMPROVED PROCESS FOR THE PREPARATION OF LEVOFLOXACIN HEMIHYDRATE
-
The present invention relates to an improved process for preparation of Levofloxacin hemihydrate having single individual impurity not more than 0.1% and free from particulate matter and from the other enantiomer (R-form) which comprises dissolving levofloxacin technical grade in aqueous alkaline solution, treating the resulting solution with activated carbon at room temperature, removing the undissolved particulate matter filtration, bringing the pH of the aqueous alkaline levofloxacin solution to neutral using dilute mineral acid, removing the precipitated particulate matter by filtration, acidifying the resulting solution, treating the acidified solution with activated carbon at room temperature, filtering the undissolved particulate matter by filtration, neutralizing the acidic solution, filtering again to remove any particulate matter present and, extracting the resulting product with chlorinated solvent and concentrating under vacuum using aqueous tetrahydrofuran or in admixture with other organic solvents to get highly pure levofloxacin hemihydrate having single individual impurity is less than 0.1% and fee from particulate matter and from the other enantiomer (R-form).
- -
-
Page/Page column 16-17
(2008/06/13)
-
- ANTIMICROBIAL QUINOLONES, THEIR COMPOSITIONS AND USES
-
Compounds of the following formula (I) are effective antimicrobial agents.
- -
-
-
- Chiral DNA gyrase inhibitors. 2. Asymmetric synthesis and biological activity of the enantiomers of 9-fluoro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-2,3-dihydro-7H-py ido[1,2,3,-de]-1,4-benzoxazine-6-carboxylic acid (ofloxacin)
-
A short and efficient synthesis, starting with (R)- and (S)-alaninol, of the two optical antipodes of the quinolone antimicrobial agent ofloxacin has been devised. Testing in vitro of the products against a range of bacteria and in an assay system incorporating purified DNA gyrase from different bacterial species demonstrates that the S-(-) enantiomer is substantially the more active.
- Mitscher,Sharma,Chu,Shen,Pernet
-
p. 2283 - 2286
(2007/10/02)
-