similarly , the mics of norfloxacin and ciprofloxacin ( the most potent of the antibiotics tested in these assays ) were several hundredfold lower than the mic of nalidixic acid ( the least potent of these antibiotics ) , but the inhibition of purified gyrase by these two quinolones was only 8- to 16-fold lower than that of nalidixic acid .
C0028365
norfloxacin
C0034428
quinolones