Anlogs of ningalin B lacking inherent cytotoxic activity may be employed to reverse multi-drug resistant (MDR) phenotype and to resensitize transformed cells, including a human colon cancer cell line (HCT116/VM46), with respect to a variety of cytotoxic agents, e.g., vinblastine and doxorubicin. In many instances, resensitization is achieved at lower doses than the prototypical agent verapamil. Total synthesis of ningalin B and its analogs was achieved using a concise, efficient approach based on a heterocyclic azadiene Diels-Alder strategy (1,2,4,5-tetrazine → 1,2-diazine → pyrrole) ideally suited for construction of the densely functionalized pyrrole core found in the natural product is detailed.
ningalin B的类似物缺乏固有的细胞毒活性,可以用来逆转多药耐药(MDR)表型,并使转化细胞重新敏感,包括人类结肠癌
细胞系(HCT116/V
M46),对多种细胞毒性药物如
长春新碱和
柔红霉素。在许多情况下,重新敏感化可以在比原型药物
维拉帕米更低的剂量下实现。通过基于杂环偶二烯-Diels-Alder策略(1,2,4,5-
四氮唑→
1,2-二嗪→
吡咯)的简洁高效方法,成功合成了ningalin B及其类似物,该方法非常适合于构建
天然产物中所发现的密集官能化
吡咯核心。