【作者】 孙福强；

【导师】 崔英德；

【作者基本信息】 广东工业大学 ， 应用化学， 2014， 博士

【摘要】 卟啉及金属卟啉类化合物是自然界中分布较为广泛的一类化合物,由于其独特的结构和性能、特别是与肿瘤细胞有特殊的亲和力而在肿瘤细胞内有聚集作用,在临床医学领域具有作为抗肿瘤药物及相关诊断试剂潜在的应用前景。G-四链体DNA是富含鸟嘌呤碱基重复序列的DNA,在金属离子存在条件下4个鸟嘌呤碱基之间通过环状氢键的互联作用循环排列连接而形成的DNA二级结构。端粒及部分可形成四链体的原癌基因序列在细胞生长、增殖、凋亡及肿瘤细胞形成过程中都具有重要的作用,从而成为当下研究最热门的小分子抗肿瘤药物靶点之一。目前已有大量关于卟啉类化合物与各种四链体相互作用的报道,也得到了很多有意义的结论。然而,目前研究的四链体主要集中在端粒四链体,对于也可形成四链体构型的原癌基因序列却鲜有报道。基于此,本文分别用常规及微波辅助合成方法制备了一系列卟啉及金属卟啉化合物,通过体外活性筛选研究了目标化合物对不同肿瘤细胞株及正常细胞株生长的抑制作用,进一步考查了几种金属卟啉和原癌基因c-myc四链体的分子识别机制。具体获得了以下几个方面的结果：1.5,10,15,20-四对甲氧基苯基卟啉铜(Ⅱ)的合成及其与c-myc G4DNA的分子识别第一步采用对甲氧基苯甲醛和吡咯为原料,以丙酸为溶剂反应制得了5,10,15,20-四对甲氧基苯基卟啉(TMOPP);第二步以TMOPP和乙酸铜为原料,在DMF中反应,粗产物过硅胶柱分离纯化得到5,10,15,20-四对甲氧基苯基卟啉铜(II)(CuTMOPP)。中间产物TMOPP及目标产物CuTMOPP经ESI-MS质谱、’HNMR、13C NMR、紫外-可见光谱、荧光光谱及红外光谱等方法进行了表征。常规与微波辅助合成方法制得的TOMPP的产率分别为21.6%和22.7%,CuTMOPP的产率分别为63.1%和64.1%。微波辅助合成目标化合物的产率略有提高、差别并不明显,但微波辅助合成技术大大缩短了反应时间,特别是第二步中常规方法要反应5h,而微波辅助合成只需要20min,明显提高了反应效率。进一步采用紫外-可见光谱、圆二色光谱、FRET熔点实验及PCR-Stop扩增实验等方法研究了该化合物和c-myc G4DNA相互作用的机制。结果发现目标化合物溶液加入c-myc G4DNA以后,紫外-可见光谱当中出现明显的减色和红移,说明CuTMOPP可以结合c-myc G4DNA;从c-myc G4DNA溶液中加入目标化合物前后的圆二色光谱来看,加入目标化合物后,CD信号的强度稍微减弱,表明CuTMOPP对c-myc G4DNA的构型有细微但可以观察到的影响,说明该化合物很可能以静电结合的方式与c-myc G4DNA相互作用；从PCR-Stop扩增实验结果来看,目标化合物可以进一步抑制c-myc相关酶的复制。2.5-[4-(4-溴代丁氧基)苯基]-10,15,20-三对甲氧基苯基卟啉铜(Ⅱ)的合成及其与c-myc G4DNA的分子识别第一步采用对羟基苯甲醛、对甲氧基苯甲醛及吡咯作为原料,以丙酸为溶剂反应,制得5-对羟基苯基-10,15,20-三对甲氧基苯基卟啉(p-HTMOPP);第二步以p-HTMOPP和1,4-二溴丁烷为原料,以DMF作为溶剂进行反应,制得5-[4-(4-溴代丁氧基)苯基]-10,15,20-三对甲氧基苯基卟啉(p-BrTMOPP);第三步以p-BrTMOPP和乙酸铜为原料,以DMF为溶剂制得目标产物5-[4-(4-溴代丁氧基)苯基]-10,15,20-三对甲氧基苯基卟啉铜(Ⅱ)(p-CuBrTMOPP),各步粗产物均过柱纯化。采用1H NMR、13C NMR、ESI-MS质谱、紫外-可见光谱,荧光光谱及红外光谱等方法对中间产物及目标化合物进行了表征。采用常规方法合成p-HTMOPP、p-BrTMOPP和p-CuBrTMOPP所得到的产率分别为5.1%、84.7%和77.9%；采用微波辅助合成法所得的产率分别为5.73%、89.2%和66.7%。两种合成方法比较,产率差别不大,但微波辅助合成明显简化了反应过程,缩短了反应时间,提高了反应效率。采用MTT法对目标化合物p-CuBrTMOPP对不同肿瘤细胞株的生长抑制作用进行了研究。通过IC50值可以看出,以顺铂作为阳性对照,该化合物对于乳腺癌细胞株(MCF-7)有很强的抑制作用,而对于其他几个肿瘤细胞株的抑制作用不明显。采用紫外-可见光谱、荧光光谱、圆二色光谱、热变性熔点实验及PCR-Stop扩增实验等研究了目标化合物p-CuBrTMOPP和c-myc G4DNA的分子识别机制。从紫外-可见光谱中加入四链体后化合物吸收峰出现的减色、红移,荧光光谱中出现的荧光强度减弱,说明p-CuBrTMOPP与c-myc G4DNA之间发生了相互结合；加入目标化合物前后,c-myc G4DNA溶液的CD光谱中,CD信号几乎没有变化,表明目标化合物对c-myc G4DNA的构型没有明显的影响。热变性熔点实验发现目标化合物在一定程度上可以稳定c-myc G4DNA的四链体构型,不过效果不是很明显,这也与CD光谱实验结论是一致的。结合几种实验结果说明该化合物可能以静电结合或沟槽结合方式和c-myc G4DNA发生相互作用,最终导致拓扑异构酶的复制受到抑制。3.5-[4-(4-溴代丁氧基)苯基]-10,15,20-三对甲氧基苯基卟啉锌(Ⅱ)的合成及其与c-myc G4DNA的分子识别5-[4-(4-溴代丁氧基)苯基]-10,15,20-三对甲氧基苯基卟啉锌(p-ZnBrTMOPP)的合成和p-CuBrTMOPP相比,除了第三步中乙酸铜改为乙酸锌以外其他条件完全相同。对p-ZnBrTMOPP进行表征,结果和预期相符。合成目标化合物采用常规方法和微波辅助方法对产率影响较小。采用MTT法对目标化合物p-ZnBrTMOPP对不同肿瘤细胞株的抑制作用进行研究,从IC50值可以看出,以顺铂作为阳性对照,该化合物对所筛选的几个肿瘤细胞株的抑制作用并不明显,而对其他肿瘤细胞株是否有抑制作用,还有待于进一步筛选。在对目标化合物p-ZnBrTMOPP和c-myc G4DNA的相互作用机制研究发现,此类化合物也可以结合并且稳定c-myc的四链体构型,但是对其构型影响不是很明显,很可能是通过外部碱基堆积发生作用的,功能上来看也可以抑制相关DNA的复制,具体的生物机制影响还在研究中。更多还原

【Abstract】 Because of its unique structure and property, especially the special affinity with the tumor cells, more and more attentions are focused on the porphyrin and metal porphyrin, a class of nature compounds, which has potential application prospect as antitumor drugs in clinical medicine and correlation diagnostic reagents. In recent years, a series of this type of complexes were designed and synthesized to apply in antitumor, and some entity with high antitumor activity have been reported. On the other hand, G-quadruplex DNA, which has been a potential target for small molecule drugs, will constructed for those G-rich DNA sequences via Hoogsteen hydrogen bonds in the presence of monovalent cations. More recently, quadruplex sequence of telomere and the original cancer gene have been become the most popular small molecule anticancer drug targets of the current research. It’s found that the promoter oncogene, which is over-expressed in up to85%of solid tumor, can also form a G-quadruplex conformation in the presence of potassium or sodium ion, and play a key role in the proliferation and apoptosis of tumor cells. Those complexes, which can stabilize the conformation of promoter oncogene G-quadruplex usually exhibit high inhibitory activity against tumor cells. There are a lot of reports about interaction of porphyrins and various G-quadruplex DNA, even some with meaningful conclusions, however, little information was obtained about the proto-oncogene sequence, which also can form quadruplex. As in this mind, in the paper a series of porphyrins and metal porphyrins were prepared under microwave-assisted and characterized by ESI-MS,1H-NMR,13C-NMR spectra and other spectroscopic methods. What’s more, as a positive control, those compounds were also synthesized by the conventional method. Furthermore, the inhibitory activity of metal porphyrins against cancer cells were evaluated by using MTT assay after a48h treatment. Besides, the binding behavior of metal porphyrins with c-myc G4DNA has been also investigated. The major results of this paper are listed in the following.1. Synthesis of5,10,15,20-tetra(4-methoxyphenyl) porphyrin with copper(II) and the molecular recognition with c-myc G4DNAFirstly,5,10,15,20-tetra(4-methoxyphenyl) porphyrin (TMOPP) was synthesized from p-methoxybenzaldehyde and pyrrole in propionic acid solution, and then5,10,15,20-tetra (4-methoxyphenyl) porphyrin copper(II)(CuTMOPP) was synthesized from TMOPP and cupric acetate in DMF solution, and purified by using column chromatograph. Both TMOPP and CuTMOPP have been characterized by1H NMR,13C NMR, ESI-MS, UV, AFS and IR spectra. Although there was little obvious difference in both methods in yields, but the reaction time was more shorten for microwave-assisted synthesis technique than that of conventional method, especially in the second step, which could increase the reaction efficiency to around15times.The interaction of CuTMOPP with c-myc G4DNA has been studied by using UV-vis, CD spectra, FRET experiments and PCR-Stop experiments, the results showed that CuTMOPP can bind with c-myc G4-DNA with high affinity. This was confirmed by the hypochromism and red shift in electronic spectra, decrease of fluorescence spectra. What’s more, the CD signal strength slightly decreased of c-myc G4DNA solution after adding the target compounds, suggesting that it could case little influence on the configuration of c-myc G4DNA. This was also confirmed by the FRET assay. Those results indicated that the target compound CuTMOPP may bind c-myc G4DNA by electrostatic binding mode, as a result, the the replication of Top polymerase was blocked, and an evaluation of biological activity of CuTMOPP is now in progress.2. Synthesis of5-[4-(4-bromobutoxy)phenyl]-10,15,20-trimethoxypheny-porphyrin with copper(II) and the molecular recognition with c-myc G4DNA5,10,15,20-tetra (4-methoxyphenyl) porphyrin (p-HTMOPP) was synthesized from p-hydroxy benzaldehyde,p-methoxy benzaldehyde and pyrrole in propionic acid solution. The crude product was purified through silica gel column. And then,5-[4-(4-bromobutoxy)phenyl]-10,15,20-trimethoxyphenyporphyrin (p-BrTMOPP) has been prepared from p-HTMOPP and1,4-dibromobutane in DMF solution. Lastly, the target compound p-CuBrTMOPP was synthesized from p-BrTMOPP and cupric acetate in DMF solution to purify raw product through column chromatography. All those complexes have been characterized by spectroscopy methods, including1H NMR,13C NMR, ESI-MS, UV, AFS and IR spectra. The yield of those target compounds though microwave-assised synthesis were not higher than that conventional synthesis method, but the difference was not significantly.The inhibitory activity of the target compound p-CuBrTMOPP against cancer cells were evaluated by using MTT assay after a48h treatment. It’s found that p-CuBrTMOPP could selectively inhibit the growth of human breast cancer cells (MCF-7) with inhibitory activity (IC50) about15.6μM, which was better than the positive control cisplatin. The interaction mechanism of the target compound p-CuBrTMOPP with c-myc G4DNA was further studied by thermal denaturation melting point and PCR-Stop experiments, as well as spectroscopy methods. Upon adding the target compound solution, obvious hypochro-mism and red shif were observed, which was also obtained in the fluorescence intensity, indicating that p-CuBrTMOPP could bind to c-myc G4DNA. From the CD spectra of c-myc G4DNA solution in the presence of p-CuBrTMOPP and the thermal denaturation melting point assay, it support that p-CuBrTMOPP could bind and stabilize the conformation of c-myc G4DNA vis electrostatic binding or groove binding. The results of PCR-Stop assay was further confirmed, which shows that the replication of DNA was blocked after treatment with the target compound.3. Synthesis of5-[4-(4-bromobutoxy) phenyl]-10,15,20-trimethoxypheny-porphyrin with zinc(Ⅱ) and the molecular recognition with c-myc G4DNAThe synthesis method of5-[4-(4-bromobutoxy) phenyl]-10,15,20-trimethoxy-phenyporphyrin with zinc(Ⅱ)(p-ZnBrTMOPP) and p-CuBrTMOPP are as the same method as above, but with cupric acetate replaced with zinc acetate. The target compounds have been characterized by spectroscopy methods. Besides, the target compounds have been also synthesized by conventional and microwave-assisted methods, with little obvious difference.The inhibitory activity of the target compounds against cancer cells were evaluated by using MTT assay. It’s found that p-ZnBrTMOPP has no inhibiting effect on the screening of tumor cell lines, And whether the activity of other tumor cell lines, still further screening.The binding behavior of p-ZnBrTMOP with c-myc G4DNA has been also investigated, suggesting that this type complex could bind and stabilize the conformation of c-myc G4DNA by electrostatic binding or groove binding mode, as a result, the replication of DNA was blocked, and an evaluation of biological activity is now in progress.更多还原