| In Vitro | In vitro activity: PBTZ169 (also known as Macozinone, an 8-Nitro-benzothiazinones (BTZs) analog) is a novel inhibitor of decaprenyl-phosphoribose-epimerase (DprE1) that displays nanomolar bactericidal activity against Mycobacterium tuberculosis in vitro. DprE1 is an essential enzyme involved in the cell wall biosynthesis of Corynebacterineae. Structure-activity relationship (SAR) studies revealed the 8-nitro group of the BTZ scaffold to be crucial for the mechanism of action, which involves formation of a semimercaptal bond with Cys387 in the active site of DprE1. When tested against thirty Nocardia brasiliensis isolates, the MIC50 and MIC90 values for PBTZ169 were 0.0075 and 0.03 μg/mL, respectively. Because Nocardia is a potential intracellular bacterium, a THP-1 macrophage monolayer was infected with N. brasiliensis HUJEG-1 and then treated with PBTZ169, resulting in a decrease in the number of colony-forming units (CFUs) at a concentration of 0.25X the in vitro value. The in vivo activity was evaluated after infecting female BALB/c mice in the right hind food-pad. After 6 weeks, treatment was initiated with PBTZ169 and its activity was compared with the first generation compound, BTZ043. Both BTZ compounds were administered at 100 mg/kg twice daily by gavage, and sulfamethoxazole/trimethoprim (SXT), at 100 mg/kg sulfamethoxazole, was used as a positive control. After 22 weeks of therapy, only PBTZ169 and SXT displayed statistically significant activity.
Kinase Assay: PBTZ169, inhibit decaprenylphosphoryl-β-d-ribose 2′-oxidase (DprE1) and display nanomolar bactericidal activity against Mycobacterium tuberculosis in vitro
Cell Assay: When tested against thirty Nocardia brasiliensis isolates, the MIC50 and MIC90 values for PBTZ169 were 0.0075 and 0.03 μg/mL, respectively. Because Nocardia is a potential intracellular bacterium, a THP-1 macrophage monolayer was infected with N. brasiliensis HUJEG-1 and then treated with PBTZ169, resulting in a decrease in the number of colony-forming units (CFUs) at a concentration of 0.25X the in vitro value. |
|---|
| In Vivo | The in vivo activity was evaluated after infecting female BALB/c mice in the right hind food-pad. After 6 weeks, treatment was initiated with PBTZ169 and its activity was compared with the first generation compound, BTZ043. Both BTZ compounds were administered at 100 mg/kg twice daily by gavage, and sulfamethoxazole/trimethoprim (SXT), at 100 mg/kg sulfamethoxazole, was used as a positive control. After 22 weeks of therapy, only PBTZ169 and SXT displayed statistically significant activity. PBTZ169 can be suspend in 0.25% hydroxy-propylmethyl-cellulose. The administertration for PBTZ169 is 100 mg/kg by gavage. The MIC50 and MIC90 values were 0.0075 and 0.030 μg/mL, respectively. The MIC for PBTZ169 for N. brasiliensis HUJEG-1 was 0.0037 μg/mL. |
|---|
m.cnreagent.com