Sahoo Santosh Kumar, Ahmad Mohammad Naiyaz, Kaul Grace, Nanduri Srinivas, Dasgupta Arunava, Chopra Sidharth, Yaddanapudi Venkata Madhavi
Department of Chemical Sciences, National Institute of Pharmaceutical Education and Research (NIPER) Balanagar Hyderabad 500037 Telangana India.
Division of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute Sector 10, Janakipuram Extension, Sitapur Road Lucknow 226031 UP India.
RSC Med Chem. 2022 Mar 10;13(5):585-593. doi: 10.1039/d1md00387a. eCollection 2022 May 25.
With growing concerns regarding target residue mutation hovering over established anti-TB pharmacophores, it is imperative to have reserve chemotypes at our disposal to curb unrestrained spread of tuberculosis. In this context, we herein present the synthesis and bio-evaluation of a library of new nitrobenzothiazinone (BTZ) congeners comprising 2-mercapto/amino-benzothiazinone tethered 1,2,3-triazole hybrids as antitubercular agents. In preliminary screening, 10 out of 37 compounds displayed substantial potency against Mtb H37Rv (MIC 0.5-8 μg mL). Structural optimization of the initial hit 5o (MIC 0.5 μg mL) led to identification of linker variants 9a, 9b, 9c, and 9d exhibiting potent anti-TB activity (MIC 0.03-0.12 μg mL). When tested against Vero cells to determine their selectivity index (SI), these compounds displayed no appreciable cytotoxicity (SI >80). Further studies on activity against drug resistant (DR) Mtb indicated these compounds to be equally potent (MIC 0.03-0.25 μg mL). The covalent docking study suggested a similar polar interaction to that of PBTZ169 with an additional and contrasting side chain interaction at the active site of Mtb DprE1 target protein. Further, the time kill kinetic study found compounds 9a and 9d to be demonstrating bactericidal efficacy, completely eliminating bacilli in 7 days at 10× MIC. The most promising compound 9d, considering its potent anti-TB activity (MIC 0.06 μg mL against drug susceptible Mtb and MIC 0.06-0.25 μg mL against DR Mtb) along with a broad therapeutic index (SI >640) demonstrating a comparable concentration dependent bactericidal efficacy to that of RIF, holds a significant edge to be translated into a potent anti-Mtb agent.
随着对既定抗结核药效基团上靶点残留突变的担忧日益增加,我们必须拥有备用的化学类型,以遏制结核病的无节制传播。在此背景下,我们在此展示了一个新的硝基苯并噻嗪酮(BTZ)类似物库的合成及生物评估,该库包含作为抗结核药物的2-巯基/氨基苯并噻嗪酮连接的1,2,3-三唑杂化物。在初步筛选中,37种化合物中有10种对结核分枝杆菌H37Rv显示出显著活性(MIC为0.5 - 8 μg/mL)。对初始命中化合物5o(MIC为0.5 μg/mL)进行结构优化,导致鉴定出具有强效抗结核活性(MIC为0.03 - 0.12 μg/mL)的连接子变体9a、9b、9c和9d。当针对Vero细胞进行测试以确定其选择性指数(SI)时,这些化合物未显示出明显的细胞毒性(SI >80)。对耐药结核分枝杆菌(DR Mtb)活性的进一步研究表明,这些化合物同样有效(MIC为0.03 - 0.25 μg/mL)。共价对接研究表明,其与PBTZ169具有相似的极性相互作用,并且在结核分枝杆菌DprE1靶蛋白的活性位点存在额外的、相反的侧链相互作用。此外,时间杀灭动力学研究发现化合物9a和9d具有杀菌效果,在10×MIC浓度下7天内可完全消除杆菌。考虑到最有前景的化合物9d具有强效抗结核活性(对药物敏感结核分枝杆菌的MIC为0.06 μg/mL,对耐药结核分枝杆菌的MIC为0.06 - 0.25 μg/mL)以及广泛的治疗指数(SI >640),显示出与利福平相当的浓度依赖性杀菌效果,具有转化为强效抗结核分枝杆菌药物的显著优势。