DK 507k

DK 507k is an orally active 8-methoxyquinolone Antibacterial agent. DK 507k targets DNA gyrase subunit A (GyrA) and modulates the function of GyrA. DK 507k inhibits the growth of various Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa and Methicillin (HY-121544)-resistant Staphylococcus aureus. DK 507k eliminates Penicillin-tolerant Streptococcus pneumoniae from the lungs of mice. DK 507k can be used in research related to sepsis and *Streptococcus pneumoniae* pneumonia^[1][2]. In Vitro:DK 507k (18 h) exhibits potent in vitro activity against a broad range of gram-positive bacterial clinical isolates, including quinolone-resistant strains, with MIC₉₀ values ranging from 0.06 μg/mL (ofloxacin-susceptible methicillin-resistant S. aureus) to 8 μg/mL (E. faecium)^[1].
DK 507k (18 h; 96 h for Legionella pneumophila; 14 days for Mycoplasma pneumoniae) exhibits potent in vitro activity against a broad range of gram-negative bacterial clinical isolates, with MIC₉₀ values ranging from 0.008 μg/mL (H. influenzae) to 1 μg/mL (K. pneumoniae, S. marcescens, Enterobacter spp., indole-positive Proteus, ofloxacin-susceptible P. aeruginosa, ofloxacin-resistant N. gonorrhoeae)^[1].
DK 507k (4 μg/mL) has low protein binding (26.7%) to mouse serum in vitro^[1].
DK 507k potently inhibits quinolone-susceptible Streptococcus pneumoniae (penicillin-susceptible, -intermediate, and -resistant strains) with an MIC₅₀ of 0.06 μg/mL and an MIC₉₀ of 0.125 μg/mL^[2].
DK 507k potently inhibits quinolone-resistant Streptococcus pneumoniae strains with an MIC₅₀ of 0.25 μg/mL and an MIC₉₀ of 0.5 μg/mL, and it is not a substrate for efflux mechanisms in these strains^[2]. In Vivo:DK 507k (1.07-9.23 mg/kg; i.v.; single dose immediately post-infection) exhibits potent efficacy against systemic septicemia in mice, with ED₅₀ values ranging from 1.07 to 9.23 mg/kg depending on the infecting pathogen, and is more effective than comparator fluoroquinolones against gram-positive organisms^[1].
DK 507k (7.5-30 mg/kg/day; s.c.; twice daily; 3 days) demonstrates dose-dependent, potent efficacy against penicillin-resistant S. pneumoniae pneumonia in mice, with complete bacterial clearance from lungs observed at 30 mg/kg/day, unlike comparator fluoroquinolones^[1].
DK 507k (10-20 mg/kg/day; p.o.; once daily; 3 days) exhibits potent efficacy against foreign body-associated urinary tract infection caused by P. aeruginosa in rats, with significant reductions in bacterial burden across all tested tissues and superior activity to ciprofloxacin at equivalent doses^[1].