DQ 2556

DQ 2556 is a semi-synthetic cephalosporin antibiotic. DQ-2556 exhibits significant activity against both Gram-positive and Gram-negative bacteria, particularly Gram-positive bacteria and Enterobacteriaceae infections. DQ 2556 exerts its bactericidal effect by interfering with cell division. DQ-2556 has a strong affinity for the penicillin-binding proteins (PBPs) of Escherichia coli: PBP1A/1B (IC₅₀ = 0.57-0.73 μg/mL) and PBP3 (IC₅₀ = 0.088 μg/mL). DQ-2556 demonstrates significant in vivo protective effects. DQ-2556 can be used in the development of injectable cephalosporins^[1][2].
In Vitro:DQ-2556 is active against Gram-positive bacteria, sensitive to methicillin-resistant Staphylococcus (MIC90 = 1.56-3.13 μg/mL), highly active against Streptococcus (MIC90 ≤ 0.05 μg/mL), and has limited activity against Enterococcus (MIC90 = 50 μg/mL)^[1][2].
DQ-2556 is active against Gram-negative bacteria, has an MIC₉₀ value of no more than 0.05 μg/mL against Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis, etc. and sensitive to Haemophilus influenzae and Neisseria gonorrhoeae with MIC90 of 0.1 μg/mL^[1][2].
DQ-2556 has the same or ≤ 4-fold MIC₉₀ value against Staphylococcus aureus, Escherichia coli, and Proteus mirabilis^[1][2].
DQ-2556 (0.0008-12.5 μg, 4 h) induces the formation of filamentous and spherical structures in Escherichia coli, and also induced cell lysis at higher concentrations^[2].
In Vivo:DQ-2556 (0.2 mL/mice, s.c., single dose) exhibits ED₅₀s against infections with S. aureus, S. pneumoniae, E. coli, K pneumoniae, and S. marcescens of 0.37, 2.75, 0.0091, 0.23, and 0.029 mg/kg mg/kg of body weight, respectively in mice infection model^[2].