双功能异羟肟酸类钌配合物作为HDAC6抑制剂的设计、合成及生物活性研究

Design,Synthesis and Biological Activity of Bifunctional Ruthenium Complexes Bearing Hydroxamic Acid as HDAC6 Inhibitors

目的 设计将具有组蛋白去乙酰化酶(histonedeacetylase,HDAC)抑制活性的芳香异羟肟酸与双联吡啶钌(Ⅱ)配合物进行偶联,合成一系列双功能异羟肟酸类钌配合物作为HDAC6选择性抑制剂,并评价其抗肿瘤活性。方法 以芳香环为连接基团(Linker),异羟肟酸为Zn^(2+)螯合基团(zinc binding group,ZBG)合成得到3个钌配合物,并通过^(1)H-NMR、^(13)C-NMR和质谱进行结构表征。荧光分析法评价化合物的HDACs抑制活性,噻唑蓝(MTT)法评价化合物对A549、MDA-MB-231、MCF-7、HepG-2和LO2细胞的体外抗增殖活性,通过分子对接研究化合物与HDAC6蛋白活性位点的结合情况。结果 目标化合物均表现出HDAC6抑制活性和选择性、体外抗肿瘤活性和靶向性,并筛选出代表化合物3,细胞毒活性与顺铂相当,且体外肿瘤靶向性远高于顺铂。结论 在药效团模型中引入较宽较大的帽子(Cap)结构(双联吡啶钌),可以更好地发挥化合物对HDAC6的特异性识别作用;同时引入具有抗肿瘤活性的钌(Ⅱ)结构,在提高化合物的HDAC6选择性抑制活性的同时兼具良好的抗肿瘤活性,证明双联吡啶钌配合物偶联芳香异羟肟酸的双功能设计是合理有效的。

OBJECTIVE To design and synthesize a series of bifunctional ruthenium complexes containing hydroxamic acid as HDAC6 selective inhibitors by conjugating aromatic hydroxamic acid with bipyridine ruthenium(Ⅱ) complexes,and investigate the in vitro antitumor activity.METHODS Three ruthenium complexes were synthesized with aromatic ring as ‘Linker' and hydroxamic acid as zinc binding group(ZBG),and their structures were characterized by ~1H-NMR,~(13)C-NMR and HRMS spectrometry.The HDAC inhibitory activity was evaluated by fluorescence analysis.The in vitro antitumor activities against A549,MDA-MB-231,MCF-7,HepG-2 and LO2 cell lines were evaluated by MTT assay.The binding of compounds to the active site of HDAC6 protein was studied by molecular docking.RESULTS All compounds showed selective HDAC6 inhibitory effect,in vitro antitumor activity and tumor-targeting activity,among which representative compound 3 exhibited comparable cytotoxic activity to cisplatin and much higher tumor-targeting activity than cisplatin.CONCLUSION The introduction of a wider “Cap”(surface recognition unit) in the pharmacophore model can improve the specific recognition of the compound against HDAC6,which proved that the design of bifunctional aromatic hydroxamic acid and bipyridine ruthenium complexes is rational.