Topoisomerase II-IN-26 

Topoisomerase II-IN-26 is a dual bacterial type II topoisomerase (Top II) inhibitor, with IC₅₀ values of 0.081 μM and 0.093 μM against Staphylococcus aureus DNA gyrase and topoisomerase IV, respectively, and IC₅₀ values of 0.906 μM and 0.103 μM against Escherichia coli DNA gyrase and topoisomerase IV, respectively. Topoisomerase II-IN-26 also shows high selectivity for human topoisomerase IIα. Topoisomerase II-IN-26 inhibits biofilm formation, reduces the metabolic activity of mature biofilms, exhibits activity against Staphylococcus aureus, MRSA strains, Escherichia coli and Acinetobacter baumannii, and possesses a post-antibiotic effect. Topoisomerase II-IN-26 can be used for the research of bacterial infections such as Staphylococcus aureus and MRSA^[1].

Topoisomerase II-IN-26 (Compound 20) (0.004-4 μg/mL; 20 h) potently inhibits growth of S. aureus and MRSA strains with MIC values of 0.004-0.008 μg/mL, and moderately inhibits E. coli (MIC = 4 μg/mL) and A. baumannii (MIC = 2 μg/mL)^[1].
Topoisomerase II-IN-26 (50 μM) has low cytotoxicity against HepG2 (50.8% residual activity at 50 μM) and HUVEC (78.4% residual activity at 50 μM) cells^[1].
Topoisomerase II-IN-26 (8 × MIC) induces a 1-hour post-antibiotic effect in MRSA at 8 × MIC, temporarily suppressing bacterial growth after transient exposure^[1].
Topoisomerase II-IN-26 (½ × MIC; 14 days) shows slower resistance development in MRSA than Gepotidacin (HY-16742), with only an 8-fold MIC increase over 14 days^[1].

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

Topoisomerase II-IN-26 (Compound 20) (0.008-0.016 μg/mL; immersion in E3 medium) robustly protects zebrafish embryos against lethal S. aureus infection at concentrations of 2 × MIC and 4 × MIC^[1].

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

512.32

C₂₂H₂₁BrF₃N₃O₃

COC1=NC2=C(N=CC(F)=C2OCC3CCC(CO3)NCC4=CC(F)=C(C(F)=C4)Br)C=C1

Room temperature in continental US; may vary elsewhere.

Please store the product under the recommended conditions in the Certificate of Analysis.

• [1]. Zorman M, et al.. Antibacterial and antibiofilm activities of novel bacterial topoisomerase inhibitors against Staphylococcus aureus and other clinically relevant pathogens. European journal of medicinal chemistry. 2026 May 22;316:118993.