A series of N-6 substituted 9-hydroxy-4-phenylpyrrolo[3,4-c]carbazole-1,3(2H,6H)-diones were prepared from N-substituted (5-methoxyphenyl)ethenylindoles. The target compounds were tested for their ability to inhibit the G2/M cell cycle checkpoint kinases, Wee1 and Chk1. Analogues with neutral or cationic N-6 side chains were potent dual inhibitors. Acidic side chains provided potent (average IC(50) 0.057 microM) and selective (average ratio 223-fold) Wee1 inhibition. Co-crystal structures of inhibitors bound to Wee1 show that the pyrrolo[3,4-c]carbazole scaffold binds in the ATP-binding site, with N-6 substituents involved in H-bonding to conserved water molecules. HT-29 cells treated with doxorubicin and then target compounds demonstrate an active Cdc2/cyclin B complex, inhibition of the doxorubicin-induced phosphorylation of tyrosine 15 of Cdc2 and abrogation of the G2 checkpoint.

中文翻译：

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N-6取代的9-羟基-4-苯基吡咯并[3,4-c]咔唑-1,3（2H，6H）-二酮作为Wee1和Chk1检查点激酶的抑制剂的合成与构效关系。

由N-取代的（5-甲氧基苯基）乙烯基吲哚制备了一系列N-6取代的9-羟基-4-苯基吡咯并[3,4-c]咔唑-1,3（2H，6H）-二酮。测试了目标化合物抑制G2 / M细胞周期检查点激酶Wee1和Chk1的能力。具有中性或阳离子N-6侧链的类似物是有效的双重抑制剂。酸性侧链提供有效的（平均IC（50）0.057 microM）和选择性的（平均比率223倍）Wee1抑制。与Wee1结合的抑制剂的共晶体结构表明，吡咯并[3,4-c]咔唑支架在ATP结合位点结合，其中N-6个取代基参与与保守水分子的氢键结合。用阿霉素然后靶向化合物处理的HT-29细胞表现出活性的Cdc2 / cyclin B复合物，