The emergence of drug-resistant tuberculosis forced the development of new drugs and screnning of more effective or less toxic analogs. Mycolic acids biosynthesis is targeted by several antituberculosis drugs toped by the isoniazid being one of the most important in tuberculosis therapy. Recently, perchlozone, acting on another step in FAS-II cycle, received official approval and was included in the Russian national clinical guidelines. Using the serial dilution method on agar 7H10 plates for perchlozone and Sensititre MYCOTB microdilution plate we analyzed the phenotypic properties of primary M. tuberculosis clinical isolates and analyzed the molecular determinants of resistance to isoniazid, ethionamide and perchlozone. We found a wide variation in the MIC of perchlozone from 2 to 64 mg/L, correlating with the overall resistance profile: the MIC was higher for MDR and pre-XDR isolates. The cross-resistance between the ethionamide and the perchlozone was driven by mutations in ethA gene encoding monooxygenase responsible for activation of both drugs. Presumably susceptible to perchlozone wild-type strains had MICs ranged 2–4 mg/L, and the breakpoint estimated to be at 4 or 8 mg/L. In conclusion, susceptibility to perchlozone retained for a part of MDR strains, as does suceptibility to ethionamide, providing the possibility of therapy for such cases based on phenotypic or molecular analysis.

N'-(5-bromofuran-2-carbonyl)isonicotinohydrazide (1) was obtained as a white solid in 83% yield by 2-methyl-6-nitrobenzoic anhydride (MNBA)/4-dimethylaminopyridine (DMAP)-catalyzed reaction of 5-bromofuran-2-carboxylic acid and isoniazid in dichloromethane at room temperature. The structure of N'-(5-bromofuran-2-carbonyl)isonicotinohydrazide (1) was elucidated by 1H NMR, 13C NMR, FTIR, and the high resolution mass spectrometers. Molecular docking screening of the title compound (1) on the cyclooxygenase-2 (COX-2) protein (PDB ID: 5IKR) exhibited that compound (1) has a good binding affinity, suggesting that it is very interesting for further structure optimization and in-depth research as a potential COX-2 inhibitor.

Tuberculosis (TB) associated with diabetes (DM) is a growing problem, particularly in low and medium-resource countries. We conducted an open-label, parallel-group, randomized, and controlled trial in a tertiary care center in Mexico City to assess TB preventive treatment with isoniazid (INH) or rifampicin (RIF) in people with DM. Participants were assigned six months of INH 300mg/day plus pyridoxine 75mg or three months of RIF 600mg/day. The primary outcomes were adverse events resulting in permanent treatment cessation and considered possibly or probably related to study drugs. We included 130 subjects, 68 randomized to INH and 62 to RIF. We prematurely halted the study based on recommendations of the Adverse Event Safety Panel. There was no difference between arms in the overall frequency of adverse events. However, the INH group had significantly more permanent treatment interruptions due to grade 2 recurrent or grade 3 or 4 hepatoxicity. In comparison, the RIF arm had more treatment interruptions due to grade 3 or 4 gastrointestinal intolerance. TB preventive treatment is not safe enough to be considered a universal indication to patients with DM and LTBI. These results underline the need to search for alternative TB prevention in DM patients with better safety profiles.