Investigation on the 1,6-naphthyridine motif: discovery and SAR study of 1H-imidazo[4,5-h][1,6]naphthyridin-2(3H)-one-based c-Met kinase inhibitors
作者:Yong Wang、Zhong-Liang Xu、Jing Ai、Xia Peng、Jian-Ping Lin、Yin-Chun Ji、Mei-Yu Geng、Ya-Qiu Long
DOI:10.1039/c2ob26710a
日期:——
The 1,6-naphthyridine motif is a multivalent scaffold in medicinal chemistry presenting various bioactivities when properly substituted. By incorporating a cyclic urea pharmacophore into the 1,6-naphthyridine framework through conformationally constraining the 7,8-positions, the resulting 1H-imidazo[4,5-h][1,6]naphthyridin-2(3H)-one was identified as a new class of c-Met kinase inhibitor. A comprehensive SAR study indicated that an N-1 alkyl substituent bearing a terminal free amino group, a hydrophobic substituted benzyl group at the N-3 position and the tricyclic core were essential for retaining effective Met inhibition of the 1H-imidazo[4,5-h][1,6]naphthyridin-2(3H)-one chemotype. Further introduction of a 4′-carboxamide phenoxy group at the C-5 position significantly improved the potency. The best c-Met kinase inhibitory activity was exemplified by 2t with an IC50 = 2.6 μM, which also displayed effective inhibition against TPR-Met phosphorylation and the proliferation of the BaF3-TPR-Met cells at low micromolar concentrations.
1,6-萘啶结构是药物化学中的一种多价支架,在适当取代时表现出多种生物活性。通过在1,6-萘啶框架中引入一个环脲药效基,并通过对7、8位进行构象约束,所得到的1H-咪唑[4,5-h][1,6]萘啶-2(3H)-酮被确认为一种新的c-Met激酶抑制剂。全面的SAR研究表明,带有末端游离氨基的N-1烷基取代基、N-3位的疏水性取代苯基团以及三环核心对于保持1H-咪唑[4,5-h][1,6]萘啶-2(3H)-酮化合物的有效Met抑制至关重要。进一步在C-5位引入4′-氨甲酰基苯氧基基团显著提高了活性。最佳的c-Met激酶抑制活性由2t所体现,IC50 = 2.6 μM,同时在低微摩尔浓度下对TPR-Met磷酸化和BaF3-TPR-Met细胞增殖表现出有效抑制。