【作者】 钱勇；

【导师】 朱海亮； 赵劲； 何川；

【作者基本信息】 南京大学 ， 生物学， 2012， 博士

【摘要】 本论文主要论述了四个部分内容：1)高选择性、高灵敏的硫化氢荧光小分子探针的制备及应用；2)方酸胺类催化剂在N-对甲苯磺酰亚胺与吲哚的不对称Friedel-Crafts反应中的应用；3)查耳酮系列衍生物的合成及生物活性评价。4)金属铱类有机化合物的合成及生物活性评价。硫化氢等水溶性硫化物在生物信号传导和代谢过程中发挥着重要作用。我们设计出一种可在中性水溶液中选择性地捕获硫化氢的化学策略。硫化氢首先与化合物结构中的醛基反应,再通过Michael加成到相邻的不饱和丙烯酸酯上形成一个Thioacetal半缩醛结构。采用这种新的化学策略,我们合成出基于两种不同荧光基团为模板的两个具有选择性检测硫化氢的荧光探针,SFP-1和SFP-2。在含有高巯基物质的生理条件下,这些探针与以硫化钠为硫化氢源或直接以硫化氢气体的反应中均表现出了显著的荧光强度增加和发射光谱迁移(SFP-1)。我们不仅展示了探针可在体外选择性检测硫化氢,还能监测酶促生成的硫化氢及在活体细胞内用于检测自由硫化氢的成像研究。在这两个荧光探针的基础上,我们又进一步研究合成出第二代更灵敏的荧光探针SFP-3和SFP-4,在生理条件下它们能以更快的速度与硫化氢反应。且它们在小牛血清体系中,对硫化氢的检测表现出了良好的线性关系。我们成功的利用这类探针检测到小鼠血清的硫化氢含量。它们在检测过程中所表现出的优良的选择性和灵敏度为更多的生物样品的检测应用提供了强有力的研究工具。在小分子催化领域中,氢键供体催化剂介导的催化反应在不对称催化中起着重要的作用。我们建立了一个氢键给体类方酸胺催化剂的化合物库,并通过筛选得到催化N-磺酰亚胺和吲哚的Friedel-Crafts反应最有效的方酸胺类催化剂,所催化得到的产物取得了较好的不对称选择性(84-96% ees)和较高的产率(85-96%)。合成出一系列具有查耳酮骨架的化合物,对其抗肿瘤增殖活性进行了评价。其中化合物2n和4q表现出良好的生物活性,对MCF-7细胞株的IC50分别为0.04士0.01μM和0.09士0.01μM。并通过计算机模拟分子对接对其潜在的生物学靶标进行了研究。合成出一系列新型的硝酮类配体及与其配位的金属铱类有机化合物,并对其抗肿瘤细胞增殖活性进行了评价,筛选出先导化合物2f,它具有显著的抗增殖活性,可诱导癌细胞发生凋亡且在体内小鼠肿瘤模型中也表现出很好的抗肿瘤生长效果。更多还原

【Abstract】 This thesis deals with four parts of work. Part I is the preparation and application of a serial of new selective and sensitive fluorescent probes for monitoring sulphide; Part II is the application of squaramide catalysts to catalyze enantioselective Friedel-Crafts reaction of indoles with N-tosyl imines; PartⅢis the synthesis, characterization and biological activities study of chalcones derivatives; PartⅣis synthesis and biological activities study of novel iridium complexes.Aqueous sulfides including hydrogen sulfide play important roles in biological signaling and metabolic processes. We have designed a selective sulfide-trapping chemical strategy comprised of sulfide addition to an aldehyde and the resulting hemithioacetal performing a Michael addition to an adjacent unsaturated acry late ester to form a thioacetal at neutral pH in aqueous solution. Employing this new strategy, two sulfide-selective fluorescent probes, SFP-1 and SFP-2, were synthesized based on two different fluorophore templates. These probes exhibit an excellent fluorescence increase and an emission maximum shift (SFP-1) in response to Na2S and H2S in a high thiol background as found under physiological conditions. We show the utility of the probes for the selective detection of sulfides, and the capacity of our probes to monitor enzymatic H2S biogenesis and image free sulfide in living cells. Then based on these two probes, we have developed other two new sensitive and selective probes SFP-3 and SFP-4 that show a significant emission increase in the fast response to sulfide over the biologically relevant pH range. The excellent linear relationship between emission intensity and sulfide concentration was obtained in bovine plasma system. These probes were successfully applied for the parallel measurement of sulfide concentration in mice blood plasma. This fast, sensitive and selective probe has the potential to be a useful tool for fast and real-time detection of sulfide in more types of biological samples. Hydrogen bond catalysis is playing an increasingly important role in the development of enantioselective reactions. We prepared a small library of new squaramide-based catalysts, and evaluated their capacity to promote Friedel-Crafts reactions of indoles. The results found chiral squaramides are highly enantioselective catalysts for Friedel-Crafts reaction of indoles with N-tosyl imines, affording 3-indolyl methanamine products in 85-96% yields and 84-96% ees.Two novel compounds with the chalcone scaffold have been designed and synthesized, and their biological activities were also evaluated as potential antiproliferative inhibitors. Compound 2n and 4q showed the most potent biological activity in vitro, which inhibited the growth of MCF-7 cells with IC50 of 0.04±0.01μM and 0.09±0.01μM, respectively. To understand the tubulin-inhibitor interaction and the selectivity of the most active compound towards tubulin, molecular modeling studies were performed to dock compound 2n and 4q into the colchicine binding site, which suggested probable inhibition mechanism. We also design, synthesis, and biological evaluation a series of novel iridium (Ⅲ) complexes with bidentate nitrone ligands as anticancer agents. The in vitro studies showed that the complexes have a strong anti-prolifcrative effect in cancer cell lines and the complex 2f with the highest activity in cell culture can induce HepG2 cells to undergo apoptosis. Furthermore, the complex 2f exhibited greater activity in inhibiting tumor growth in vivo.更多还原