TABLE 6.

Inhibition of E. coli DNA gyrase supercoiling by 5,6-bridged dioxinoquinolones and comparator quinolones

QuinoloneIC50 (μg/ml)aQR/WT ratiob
WT gyraseQR gyrase
PGE-83677697.581.310.8
PGE-659649162.3>500
PGE-78724116.5102.115.7
PGE-8789356.677.111.6
PGE-6116542>500>500
PGE-5215205219.7>500
PGE-9604297179.5>500
Nalidixic Acid15.9>500
Ciprofloxacin0.1216.1134.3
Clinafloxacin0.0320.4513.8
  • a WT, wild type; QR, quinolone resistant (GyrA S83L).

  • b The QR/WT ratio were calculated by dividing the IC50 for the wild-type gyrase by the IC50 for the quinolone-resistant gyrase. —, could not be calculated.