設計與合成吲哚-2-酮衍生物作為潛能蛋白激酶 抑制劑及其活性評估

Abstract

本論文之研究宗旨為利用二氫吲哚-2-酮衍生物，開發一新系列多重激酶抑制劑。先前的研究指出，3-（吡咯-2-基亞甲基）二氫吲哚-2 -酮衍生物為多重激酶抑制劑；而本研究將原先於六位的脲基團置換為苯甲酰脲基團，以觀察是否可以得 到更強效之多重激酶抑制劑。體外生物活性評估結果顯示，第二章中之化合物69 對Aurora B、Flt-3、LCK與c-Kit等激酶之IC50可以分別達到0.4 nM、0.5 nM、2.3 nM與14.0 nM。此化合物更被發現可以抑制A549肺癌細胞與HepG2肝癌細胞中組蛋白H3之磷酸化，代表胞內Aurora B的活性能被有效抑制；並且造成人類非小細胞肺癌細胞A549形成多倍體並細胞凋亡。 為了進一步開發新型激酶抑制劑，我們沿用二氫吲哚-2-酮之結構，並利用構象限制的3-烷基/芳基-2-氧代咪唑烷-1-甲酰之設計理念，環化丙二醯胺以得到一 系列衍生物。此系列化合物中，第三章之化合物25為強效Aurora B抑制劑（IC50 = 2.7 nM），亦有Flt-3抑制活性（IC50 = 119.3 nM）。此化合物同樣也對A549與HepG2細胞具有細胞毒性，其IC50分別可以達到0.83 μM與0.87 μM。 因Flt-3/Aurora 雙效抑制劑被認為是相當有潛力的急性髓細胞性白血病治療策 略，本論文所開發出來的抑制劑可以做為這類藥物開發的先導化合物。研究結果亦顯示了二氫吲哚-2-酮衍生物在激酶抑制劑開發上扮演的重要角色。

The aim of this dissertation is to design, synthesize and biologically evaluate novel multikinase inhibitors with indolin-2-one scaffold. Indolin-2-one is considered as an ideal scaffold for the design of kinase inhibitors. Thus to prepare novel multikinase inhibitors, 6-benzoylureido derivatives containing a 3-(pyrrol-2-ylmethylidene)indolin-2-one scaffold were prepared by replacing the ureido moiety in 6-arylureidoindolin-2-ones that had been shown to act as this type of inhibitor. Structure activity relationship studies of these compounds identified (Z)-N-(2-(pyrrolidin-1-yl)ethyl)-5-((6-(3-(2-fluoro-4-methoxybenzoyl)ureido)-2-oxoindolin-3-ylidene)methyl)-2,4-dimethyl-1H-pyrrole-3-carboxamide as an inhibitor of the kinases Aurora B, Flt-3, LCK and c-Kit with IC50 values of 0.4 nM, 0.5 nM, 2.3 nM, and 14.0 nM, respectively. It also inhibited phosphorylation of histone H3 in A549 and HepG2 cells and also caused human NSCLC A549 cells to form polyploid cells and undergo apoptosis. Furthermore, with a keen interest to identify novel kinase inhibitors, conformationally restricted 3-alkyl/aryl-2-oxoimidazolidine-1-carboxamido derivatives of indolin-2-one scaffold were designed by conformational restriction of malonamido moiety (a bioisoster of benzoylureido moiety) present in previously identified multikinase inhibitors. Structure activity relationship studies of this series of compounds led to the identification of 2-(5-((6-(3-cyclopropyl-2-oxoimidazolidine-1-carboxamido)-2-oxoindolin-3-ylidene)methyl)-2,4-dimethyl-1H-pyrrol-3-yl)acetic acid, which is a potent inhibitor of Aurora B (IC50 = 2.7 nM) and moderate inhibitor of Flt-3 kinase (IC50 = 119.3 nM). This compound also showed cytotoxicity to human lung cancer A549 cells and hepatocellular carcinoma HepG2 cells in submicromolar range. The strategy of dual Flt-3/Aurora inhibition is predicted to offer potential therapeutic benefits in acute myeloid leukemia (AML). Therefore, the compounds prepared in this dissertation with potent inhibitory activity against Aurora B and Flt-3, may serve as lead for the development of potential therapeutic agents against AML. It also highlights the significance of indolin-2-one scaffold for the design of novel kinase inhibitors.