In search for new molecular entities as anti-TB agents, the benzimidazoquinazoline polyheterocyclic scaffold has been designed adopting the scaffold hopping strategy. Thirty-two compounds have been synthesized through an improved tandem decarboxylative nucleophilic addition cyclocondensation reaction of o-phenylenediamine with isatoic anhydride followed by further cyclocondensation of the intermediately formed 2-(o-aminoaryl)benzimidazole with trialkyl orthoformate/acetate. The resultant benzimidazoquinazolines were evaluated in vitro for anti-TB activity against M. tuberculosis H37Rv (ATCC27294 strain). Fourteen compounds exhibiting MIC values in the range of 0.4-6.25 µg/mL were subjected to cell viability test against RAW 264.7 cell lines and were found to be non-toxic (<30% inhibition at 50 µg/mL). The active compounds were further evaluated against INH resistant Mtb strains. The most active compound 6x [MIC (H37Rv) of 0.4 µg/mL] and the compound 6d [MIC (H37Rv) of 0.78 µg/mL] were also found to be active against INH resistant Mtb strain with MIC values of 12.5 and 0.78 µg/mL, respectively.

中文翻译：

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苯并咪唑并喹唑啉类作为新型有效的抗结核化学型：设计，合成和生物学评估。

为了寻找作为抗结核病药物的新分子实体，采用支架跳跃策略设计了苯并咪唑并喹唑啉多杂环支架。通过改进的邻苯二胺与isatoic酸酐的串联脱羧亲核加成环缩合反应，然后进一步将中间形成的2-（邻氨基芳基）苯并咪唑与原甲酸三烷基酯/乙酸酯进一步环缩合，合成了32种化合物。体外评估所得的苯并咪唑并喹唑啉类抗结核分枝杆菌H37Rv（ATCC27294菌株）的抗TB活性。对MIC值在0.4-6.25 µg / mL范围内的14种化合物进行了针对RAW 264.7细胞系的细胞生存力测试，发现它们是无毒的（在50 µg / mL下抑制率小于30％）。进一步评估了活性化合物的抗INH抗性Mtb菌株。还发现活性最高的化合物6x [MIC（H37Rv）为0.4 µg / mL]和化合物6d [MIC（H37Rv）为0.78 µg / mL]对INH抗性Mtb菌株具有MIC和MIC值分别为12.5和0.78 µg。 / mL。