Medicinal Chemistry Laboratory, Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Mangalore 575 025, India.
Eur J Med Chem. 2012 Aug;54:900-6. doi: 10.1016/j.ejmech.2012.05.027. Epub 2012 Jun 1.
Two new series of quinoline incorporated benzimidazole derivatives (4a-i and 8a-f) were synthesized from substituted aniline and isatin through multi-step reaction. 6-substituted-4-carboxyquinolines (3a,b and 7) were synthesized by multi component one pot reactions (via Doebner reaction and Pfitzinger reaction respectively) and the targeted benzimidazole derivatives were obtained by the reaction of 6-substituted-4-carboxyquinolines (3a,b and 7) with substituted aromatic diamines in acidic media. All the newly synthesized compounds were characterized by IR, NMR mass spectral study and also by C, H, N analyses. The final compounds were screened for their in-vitro antibacterial and antifungal activity by well plate method (zone of inhibition). The results revealed that, compounds 4c, 4d, 8c and 8d showed significant antibacterial activity. The compound 8b was found to be potent antifungal agent. 4a, 8a and 8f showed moderate to good antimicrobial activity as compared to the standard drugs against all tested microbial strains.
两个新系列的喹啉合并苯并咪唑衍生物（4a-i 和 8a-f）是由取代苯胺和色胺通过多步反应合成的。6-取代-4-羧酸喹啉（3a，b 和 7）是通过多组分一锅反应（分别通过 Doebner 反应和 Pfitzinger 反应）合成的，目标苯并咪唑衍生物是通过 6-取代-4-羧酸喹啉（3a，b 和 7）与取代芳族二胺在酸性介质中的反应得到的。所有新合成的化合物都通过 IR、NMR 质谱研究以及 C、H、N 分析进行了表征。最后通过平板法（抑菌圈）筛选了这些化合物的体外抗菌和抗真菌活性。结果表明，化合物 4c、4d、8c 和 8d 表现出显著的抗菌活性。化合物 8b 被发现是一种有效的抗真菌剂。与标准药物相比，化合物 4a、8a 和 8f 对所有测试的微生物菌株都表现出中等至良好的抗菌活性。
