Figure 1
![Figure 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2F1472-6807-11-47/MediaObjects/12900_2011_Article_397_Fig1_HTML.jpg)
Common structural features of quinolones. (A) The modifications were made at positions 3 and 7, essential for binding to DNA-gyrase complex and antibacterial spectrum respectively [20]. (B) and (C) are the chemical structures of gatifloxacin and moxifloxacin respectively.