【作者】 王建红；

【导师】 赵瑾；

【作者基本信息】 河南大学 ， 高分子化学与物理， 2008， 博士

【摘要】 恶性肿瘤（tumor）是严重威胁人类生命的疾病,目前已经成为引起人类死亡的第一或第二位原因。化学药物治疗是肿瘤治疗中发展最快的一个领域。近年来,已经开发出大量的药物用于治疗肿瘤。但是,现有的抗肿瘤药物普遍存在治疗选择性低、容易产生耐药性的缺点,在治疗疾病的同时往往产生严重的毒副作用,因而使它们的临床应用受到限制。解决此类问题的关键是发现和确定有效的药物作用靶点,开发出具有靶点定向作用的抗肿瘤药物。随着科学技术的迅猛发展及分子生物学技术的进展,围绕提高抗肿瘤药物作用靶向性的研究日益活跃,其中,以多胺（polyamine）为靶向载体的抗肿瘤药物研究是目前国际上药物研究的热点方向之一。多胺是细胞必需的生长因子,与肿瘤细胞生长密切相关,它在肿瘤细胞内生物代谢过程的关键环节可作为抗癌药物设计的切入点。对多胺的前期研究结果表明,肿瘤细胞膜上的多胺转运通道（polyamine transporter,PAT）能对多胺及其结构类似物优先识别并转运进入细胞。因此,利用多胺骨架结构的运载功能可以实现抗肿瘤药效团靶向进入肿瘤细胞内,从而提高药物作用的选择性。本论文基于多胺类似物的构效关系,选择PAT为作用靶点,以AN-44为先导化合物,设计、合成了两大系列具有线型骨架结构的多胺缀合物,其中包括7个不同多胺链长的化合物T1-T7以及8个含有不同芳香体系的缀合物T8-T15。通过药理活性评价考察多胺链的长度以及键接药效团大小对抗肿瘤活性的影响。同时,我们还对天然活性产物进行多胺结构修饰,设计、合成了两个系列的“天然活性产物-多胺”缀合物T16-T24和T25-T32,初步评价了它们的抗肿瘤活性以及增效抗肿瘤药物的作用。本文尝试多条反应路线用于线型多胺骨架结构的简便、高效合成。对于T1-T7系列目标化合物,我们最终采用均三甲基苯磺酰基（Mts）作为氨/胺基的保护基,利用经典的Gabriel合成氨反应策略实现了多胺链的高效合成。然而,当尝试用叔丁氧羰基（Boc）作为氨/胺基的保护基进行多胺链的合成时,我们发现所经历的Gabriel反应进程出现了开环副反应,经“一锅法”改进,意外地以较高收率得到目标物。对于T8-T15系列目标化合物,我们采用砌块对接策略高效地合成了4-4-2多胺骨架。并且用同样的方法合成对照物AN-44（C1）,结果发现反应收率及经济性均比文献方法有显著提高。对于多胺修饰天然产物的系列化合物T16-T24,我们结合天然物质结构的特殊性,采用比较温和的反应条件实现了目标物的合成,并使天然结构片段构型得以保持。本文合成各种中间体和目标化合物共84个,其中74个新化合物未见文献报道,包括35个目标化合物,化合物的结构经MS,¹H/¹³C NMR波谱分析及元素分析等方法确证。本文对所合成的目标化合物进行了初步体外抗肿瘤活性评价,主要选取L1210,CHO,HeLa,B16,K562等肿瘤细胞株,测定化合物使50%的肿瘤细胞生长受到抑制的浓度(IC₅₀,μM)。结果表明,化合物T1-T7整体上具有中等到较强的肿瘤细胞生长抑制作用。基于细胞水平的药理活性筛选发现,化合物T6具有显著的PAT识别作用,可以作为具有靶向抗肿瘤化合物的先导物进行深入研究。化合物T8-T15对HeLa细胞表现出较强的生长抑制活性,其中的化合物T11的IC₅₀达到0.58μM,活性最强。化合物T16能增效长春新碱（VBL）的抗肿瘤作用,协同系数S=2.07,优于文献报道的化合物SDB。本文对初筛效果良好的化合物T6,进一步从分子水平及动物整体水平进行了深入研究,探讨其可能作用的分子靶点及在生物体内的抗肿瘤活性。结果发现,T6能够较强地抑制DNA拓扑异构酶（Ⅱ型）的解旋作用,对多胺合成酶ODC也具有明显的抑制作用,T6在一定浓度下能诱导B16肿瘤细胞的凋亡性死亡,这表明化合物T6具有多靶点的作用模式。对荷瘤小鼠的活性实验表明,化合物T6不但能显著抑制小鼠体内实体瘤的增长（在10 mg/kg/d剂量连续7天给药后,对肿瘤的抑制率达到56.9%）,而且化合物T6按10 mg/kg/d给药剂量下,小鼠的平均存活时间分别提高到29.75±1.8天,平均存活时间提高了约2.29倍。更多还原

【Abstract】 Tumor is still a lethal disease threatening human beings and it has become the major cause which resulted in death of lives.Chemotherapy is one of the most rapidly developing strategies in cancer therapy.To date,although a large number of drugs have been developed and used in neoplasm therapy,they always exhibit many drawbacks such as low tumor-target and multidrug resistance and bring out severe side effects in clinical use.Thus,their application is greatly limited.Determination of the drug target becomes important to breach such trouble and be helpful to develop new efficient drugs.With the development of modern technology and molecular biochemistry,the research on tumor target has become more and more active in anticancer drugs.Among them,polyamine is one of the hot topics in the development of antineoplastic drugs. Polyamines are ubiquitous constituents of eukaryotic cells and play a key role in cellular physiology.The pathways for polyamine metabolism have been elucidated and provided a target for the design of antitumor agents.The polyamine transporter could recognize polyamine and its analogues,and preferentially ferry them into cells.Thus, the polyamine backbone could act as potential carriers for drug delivery.As a result, the tumor targeting of drugs were improved.Based on the structure-activity relationship of polyamine analogues,we reported in this dissertation the design and synthesis of two series of linear polyamine conjugations and their investigation on polyamine transporter affinity using AN-44 as the lead compound.Compounds T1-7 were designed for comparison of the different polyamine chains,and T8-15 were evaluated for the influence of dissimilar pharmacophore conjugated.Moreover,we reported the structural modification of natural products T16-32 and investigated the synergistic effect on anticancer drug.We employed various synthetic routes in efficient construction of polyamine backbones.The classical Garbiel procedure was performed during the synthesis of target compounds using MtsC1 or Boc₂O as the protection agents.During the synthesis of T1-7,the side reaction was detected,and the title compound was obtained with "one-pot" amelioration,and the yield was also improved unexpectedly.In this thesis,amount to 84 compounds were synthesized including 74 initial ones, their chemical structures were confirmed by MS,¹H/¹³C NMR and elemental analysis.The in vitro antitumor activities of target compounds were investigated in L1210, CHO,HeLa,B16 and K562 tumor cells,and the results revealed that the compound T6, from T1-7 series,could be recognized by PAT,and could act as potential tumor targeting agent for further evaluation.Among the T16-32 series,compound T16 was the most potent agent which showed prominent synergistic effect on VBL.Its synergy coefficient was 2.07 which was higher than that of reference compound SDB.With T6 in hand,we further investigated the antitumor activity both on enzyme and whole animal levels.It turned out that T6 had obvious effects on TOPOⅡand ODC,and that T6 could induce the apoptosis of B16 tumor cells.The in vivo antitumor activity revealed that T6 could not only inhibit the tumor growth,but also obviously increase the lifespan of tumor-bear mice.For example,at the dose of 10 mg/kg/d,the tumor growth was inhibited by 56.9%and the mean survival time of tumor-bear mice was increased to 2.29 folds in comparison with the control.更多还原