Rifaquizinone

Rifaquizinone exhibits Rifampicin (HY-B0272)-like potency against wild-type Staphylococcus aureus σA RNA polymerase (IC₅₀ = 0.034 μM)^[1].
Rifaquizinone (incubated for 1 h) acts as a balanced inhibitor of wild-type Staphylococcus aureus DNA gyrase (CC₅₀ = 1.5 μM) and DNA topoisomerase IV (CC₅₀ = 1.7 μM), and retains activity against the fluoroquinolone-resistant ParC ^(S80F) DNA topoisomerase IV mutant (CC₅₀ = 2.7 μM)^[1].
Rifaquizinone exhibits potent antibacterial activity against wild-type and quinolone-resistant Staphylococcus aureus strains (MIC = 0.008-0.015 μg/mL), shows a moderate increase in MIC against Rifampicin-resistant strains (MIC = 0.06-2 μg/mL), and has the highest MIC against strains resistant to both Rifampicin and quinolones^[1].
Single-step resistance to Rifaquizinone (0.08-0.8 μg/mL) in wild-type Staphylococcus aureus is mediated by rpoB mutations, whereas in Rifampicin-resistant strains, resistance is mediated by gyrA and parC/parE mutations, with no involvement of efflux mechanisms^[1].
Rifaquizinone (0.5 μg/mL; up to 200 min) inhibits primary RNA synthesis in wild-type and quinolone-resistant Staphylococcus aureus strains CB190 and CB814, whereas it instead inhibits primary DNA synthesis in the Rifampicin-resistant strain CB370^[1].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.