A series of novel 3,5-diaryl-1H-pyrazolo[3,4-b]pyridines as tubulin polymerization inhibitors targeting the colchicine site were designed via ring tethering strategy, which was supported by conformational analysis. The general, chemically unstable and rotational linker, carbanyl group, was locked by 1H-pyrazolo[3,4-b]pyridine to avoid carbonyl reduction and restrict the instability of molecular conformation caused by the rotation of the carbon-carbon single bond beside carbonyl group. All of target compounds were synthesized and evaluated for their antiproliferative activities against three human cancer lines (SGC-7901, A549 and HeLa) by MTT assay. Most of these compounds showed prominent in vitro potency and the most potent compound in this scaffold 13d (SGC-7901: IC₅₀ = 13 nM) could significantly inhibit tubulin polymerization and strongly disrupt cytoskeleton. The results of molecular modeling study revealed that 13d interacts with tubulin by binding to the colchicine site.

通过环系策略设计了一系列新型的3,5-二芳基-1 H-吡唑并[3,4- b ]吡啶类化合物作为针对秋水仙碱位点的微管蛋白聚合抑制剂，并得到了构象分析的支持。一般的化学上不稳定的旋转接头碳原子团被1 H-吡唑并[3,4- b ]吡啶锁定，以避免羰基还原并限制由碳-碳单键旋转引起的分子构象的不稳定性羰基。合成了所有目标化合物，并通过MTT分析评估了其对三种人类癌症细胞系（SGC-7901，A549和HeLa）的抗增殖活性。这些化合物大多数显示出突出的体外效力和该支架13d中最有效的化合物（SGC-7901：IC ₅₀  = 13 nM）可以显着抑制微管蛋白聚合并强烈破坏细胞骨架。分子建模研究的结果表明，13d通过与秋水仙碱位点结合而与微管蛋白相互作用。