天然产物海兔毒素10及其类似物的合成研究

发布时间：2018-01-19 04:16

本文关键词： 海兔毒素10 合成多肽类似物前药抗肿瘤活性　出处：《华东师范大学》2017年博士论文　论文类型：学位论文

【摘要】：海兔毒素10是从印度洋的海兔Dolabbella auriclaria体内分离得到的一种海洋天然产物,它是一种高细胞毒性的多肽类化合物,对于多种肿瘤细胞都显示出极强的抑制能力。虽然海兔毒素10作为抗肿瘤药在临床前研究显示出良好的效果,但由于其在临床研究中显示出太大的毒性,故未能通过临床试验。随后,一系列被称为"auristatins"的海兔毒素10衍生物被开发出来,在临床试验研究中被大量应用。而由其中一个化合物MMAE发展起来的抗体药物偶联物(ADC)"Adcetris"已经作为治疗霍奇金淋巴瘤的药物于2011年被FDA批准上市。此外,目前进入临床研究的ADC药物有将近一半都是以海兔毒素10的衍生物作为药效分子的,极有可能以此开发得到新的抗肿瘤药。另一方面,海兔毒素10有着复杂的多手性中心结构,其合成具有一定挑战,所以无论从化学合成的角度还是药物化学的角度来看,对海兔毒素10及其类似物的合成做进一步的研究都有着极为重要的意义。本论文的前言综述了一些多肽以及环肽类化合物的合成方法研究进展。主要介绍了具有抗肿瘤活性的天然海洋肽类化合物,重点介绍海兔毒素10的发现、合成以及其衍生物的发展。本论文的研究内容主要包括以下四个部分:第一部分,首先分别对海兔毒素10的三个关键中间体片段Dil,Dap以及Doe的合成进行了深入的研究。通过对路线优化和反应条件筛选,基本上能够高效大量地合成得到这三个关键中间体以及Dil和Dap片段的异构体。随后通过液相合成法完成了海兔毒素10以及其中三个手性异构体的合成。第二部分,在目前已有文献报道对海兔毒素10的构效关系研究的基础上,以海兔毒素10的衍生物MMAF为模板,对其进行N-端结构修饰。将N-端氨基酸的氨基修饰为伯胺,同时在氨基酸的αα-位引入不同的取代基,完成了 13个新的海兔毒素10类似物的合成。随后又研究了构象的改变对于海兔毒素10活性的影响,将合成得到的这一系列线性肽经酰胺缩合环化,合成得到12个新的海兔毒素10环肽类似物。第三部分,针对海兔毒素10毒性太大这一特点,将海兔毒素10设计为前药的形式。主要是通过将其改造为环肽酯或者在分子结构里引入酶可裂解型二肽接头来实现。第四部分,对合成得到的海兔毒素10类似物进行体外的抗肿瘤活性评估,通过测定这些化合物对HCT-116人结肠癌的的半数抑制浓度(IC50)来完成。测试结果显示,其中10个N-端修饰的类似物都表现出比对照化合物MMAF更好的体外抗HCT-116细胞活性,活性最好的为化合物37f,IC50达到0.07μM。而对于环肽化合物,因为构象的改变,活性比相对应的线性肽普遍降低,但是环肽化合物40k和401活性却得到提高,IC50均达到0.03 μM,表现出了较强的抗肿瘤活性。
[Abstract]:Marine rabbit toxin 10 is a natural marine product isolated from Dolabbella auriclaria of the Indian Ocean. It is a highly cytotoxic polypeptide compound. Although the antitumor drug has shown a good effect in preclinical studies, it has shown too much toxicity in clinical research because of its strong inhibitory effect on many kinds of tumor cells. A series of Hare toxin 10 derivatives called "auristatins" were subsequently developed. It has been widely used in clinical trials. The antibody-drug coupling developed from one of the compounds, MMAE, is ADCA). "Adcetris" was approved by FDA on 2011 as a treatment for Hodgkin's lymphoma. At present, nearly half of the ADC drugs that enter the clinical research are using the derivatives of Hippotoxin 10 as effector molecules, which is very likely to be used to develop new anti-tumor drugs. On the other hand, it is possible to develop new antitumor drugs. Rabbit toxin 10 has a complex multi-chiral central structure, and its synthesis has some challenges, so it is not only from the perspective of chemical synthesis, but also from the point of view of pharmacochemistry. It is of great significance to further study the synthesis of sea rabbit toxin 10 and its analogues. The foreword of this paper summarizes the progress in the synthesis of some peptides and cyclic peptide compounds. Natural marine peptide compounds with antitumor activity. The discovery, synthesis and the development of its derivatives are introduced in detail. The research contents of this thesis mainly include the following four parts: the first part. Firstly, the synthesis of three key intermediate fragments of rabbit toxin 10, Dilo Dap and Doe, were studied, and the route optimization and reaction conditions were selected. The three key intermediates and the isomers of Dil and Dap fragments can be synthesized in large quantities by high efficiency. Subsequently, the synthesis of Hare toxin 10 and three of the chiral isomers were completed by liquid phase synthesis. Part two. On the basis of the research on the structure-activity relationship of Hippotoxin 10 in the literature, the derivative MMAF of Hippotoxin 10 was used as template. The amino groups of N-terminal amino acids were modified to primary amines. At the same time, different substituents were introduced into the 伪 -sites of amino acids. After the synthesis of 13 new mimics of toxin 10, the effects of conformational changes on the activity of toxin 10 were studied, and the synthesized linear peptides were cyclized by amide condensation. A total of 12 new cyclic peptide analogues were synthesized. The third part is aimed at the characteristic that the toxicity of Hippotoxin 10 is too high. It was designed as prodrug form, mainly by transforming it into cyclic peptide ester or introducing enzyme cleavable dipeptide junction into molecular structure to realize. 4th part. The antitumor activity of synthetic rabbit toxin 10 analogue was evaluated in vitro. This was done by measuring the half inhibitory concentration (IC50) of these compounds on HCT-116 human colon cancer. Ten of the N-terminal modified analogs showed better anti-#en1# cell activity than control compound MMAF in vitro, and the best activity was compound 37f. IC50 reached 0.07 渭 M. for cyclic peptide compounds, the activity of cyclic peptide compounds was generally lower than that of corresponding linear peptides due to conformation change, but the activities of cyclic peptide compounds 40k and 401were increased. IC50 reached 0.03 渭 M, showing strong anti-tumor activity.
【学位授予单位】：华东师范大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O629

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