Abstract

As part of an ongoing effort to develop new anti-tubercular agents, a series of novel indole-fused spirochromene hybrids (7a–l) were efficiently synthesized in excellent yields by the popular ‘Fisher–Indole synthesis’ approach. The structure elucidation of the target compounds was carried out by different spectral techniques including ¹H-NMR, ¹³C-NMR, ESI Mass, and FTIR analysis. Additionally, the proposed structure of 7i was proved by single-crystal X-ray analysis. These compounds (7a–l) were screened for in vitro anti-tubercular activity against Mycobacterium tuberculosis H37Rv (ATCC 27294) strain. The results showed that most of the targets exhibited promising antimycobacterial activity with MICs of 1.56–6.25 μg/mL and weak cytotoxicity (19.93–32.16% at 50 μg/mL). Among them, compound 7l was found to be the most active compound (MIC of 1.56 μg/mL) with a good safety profile (32.16% at 50 μg/mL).

Graphic abstract

中文翻译：

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吲哚稠合螺色烯作为潜在的抗结核药物：设计、合成和体外评估。

 抽象的

作为开发新型抗结核药物持续努力的一部分，通过流行的“费舍尔-吲哚合成”方法，以优异的产率有效合成了一系列新型吲哚稠合螺色烯杂化物（ 7a-l ）。通过不同的光谱技术，包括¹ H-NMR、 ¹³ C-NMR、ESI Mass 和 FTIR 分析，对目标化合物的结构进行了解析。此外， 7i的拟议结构通过单晶 X 射线分析得到了证明。筛选这些化合物 ( 7a–l ) 的体外抗结核活性，以了解其针对结核分枝杆菌H37Rv (ATCC 27294) 菌株的活性。结果显示，大多数靶标表现出良好的抗分枝杆菌活性，MIC 为 1.56-6.25 μg/mL，细胞毒性较弱（50 μg/mL 时为 19.93-32.16%）。其中，化合物7l被发现是最活跃的化合物（MIC 为 1.56 μg/mL），具有良好的安全性（50 μg/mL 时为 32.16%）。

 图文摘要