肠道靶向TGR5激动剂的设计、合成及生物活性评价

发布时间：2018-04-26 03:02

  本文选题：TGR5 + 肠道靶向药物　； 参考：《中国科学院大学(中国科学院上海药物研究所)》2017年博士论文

【摘要】：肠道靶向药物是一类口服后选择性地在肠道发挥药效的药物。这些化合物具有血浆暴露量低,肠道组织中浓度高的特点,因此肠道靶向药物有可能避免高系统暴露量相关的副作用。这种设计策略被广泛运用到糖尿病、肥胖症、感染性疾病和炎症等疾病的药物开发中。TGR5是细胞膜表面的GPCR,其内源性配体是胆汁酸。TGR5受体参与了血糖稳态、免疫系统、肝胆功能、胃肠道功能等的调节。其中最主要且明确的是TGR5受体对于血糖稳态的调节。肠道分泌细胞上TGR5的激动会促进GLP-1、GLP-2和PYY的分泌。GLP-1可以促进血糖依赖的胰岛素释放,抑制食欲,减缓胃排空等,从而维持血糖稳态。GLP-2主要维系肠道的完整,促进肠道组织的生长。PYY发挥抑制食欲的作用。因此TGR5激动剂是潜在的抗糖尿病和肠道疾病的药物。但TGR5受体在胆囊上的激动会导致胆汁排出受阻,胆囊体积增大。开发肠道靶向的TGR5激动剂有可能规避胆汁充盈的副作用。本文主要从软药策略出发进行肠道靶向TGR5激动剂的设计。软药是一类吸收后迅速被代谢失活的化合物。本文首先通过对高体外活性的B1结构优化,然后对化合物库的整理,最终找到了酯类化合物B12a,其可在血浆中代谢成低活性的羧酸B13a。为了加快化合物血浆代谢速率,分别通过去除B12a苯并呋喃环上的氯原子,酯基位点更换成更高活性的酯、吡啶环位点的变换的方式最终得到了C1g,C1i等化合物,它们具有较好的体外活性和血浆代谢速率。口服药代试验中C1g,C1i在血浆、胆囊、胆汁中的浓度都极低。与之相对应的是,无论是在ICR小鼠连续三天给药还是db/db小鼠连续四天大剂量给药试验中,C1g,C1i都没有表现出明显的胆汁充盈副作用。系统的研究还表明化合物的血浆代谢速率越快,体内暴露量越低,胆囊副作用越微弱。在ICR小鼠单次口服OGTT试验中,C1g,C1i都表现出了显著的降糖活性。同时这系列化合物在配样所用的0.25%的CMC-Na水溶液中和p H 1.2的模拟胃液中的稳定性能满足体内试验的需求。以上试验表明了软药策略用于肠道靶向TGR5激动剂的可行性。但C1g,C1i还存在一些缺陷,一是C1g与C1i的Caco-2细胞渗透性还并不低(Papp约为1×10-6 cm/s);二是体内药代试验中,两个化合物在肠道组织中的浓度还不够高。从提高化合物极性的角度出发进行改造,希望降低这类软药化合物的细胞渗透性,同时增加化合物在肠道组织中的浓度。分别在酯基位点、四氢喹喔啉位点、中间吡啶环位点修饰,引入大极性的基团。最终发现吡啶氮原子修饰成季铵盐的D5g具有较好的h TGR5体外活性,较快的血浆代谢速率,同时Caco-2细胞渗透性极低,Papp仅为0.01×10-6 cm/s。但D5g及类似化合物的体外活性都存在着显著的种属差异,这种种属差异部分来源于苯并呋喃环。因此设计将C1g,C1i类似物和D5g类似物的苯并呋喃环开环,分别得到D7j,D7l和D9m。D7j,D7l与C1g,C1i活性接近,而血浆中水解速率更快。而D9m的体外活性的种属差异有所缓解,h TGR5 EC50为84 n M,而m TGR5 EC50为499 n M,两者差异仅5.9倍。其m TGR5活性是吡啶季铵盐类里唯一活性能达到几百n M水平的化合物。另一方面,降低化合物的水溶性也能显著降低化合物的吸收。链型结构并环有可能增加其晶格能,从而降低水溶性。同时并环策略还能增加化合物的新颖性,有利于后期的专利保护。本文以A21a和B1为基础,通过不同位置的并环和最初的构效关系优化,初步找到了取代苯并含氮杂环类化合物具有中等的体外活性,其中最优的化合物为E5c。
[Abstract]:Intestinal targeting drugs are a class of drugs that are selectively used in the intestinal tract after oral administration. These compounds have low levels of plasma exposure and high concentrations in the intestinal tissue. Therefore, intestinal targeting drugs may avoid high systemic exposure related side effects. This design strategy is widely used in diabetes, obesity, infectious diseases. In the development of diseases such as disease and inflammation,.TGR5 is the GPCR on the surface of the cell membrane, and its endogenous ligand is that the bile acid.TGR5 receptor participates in the regulation of blood glucose homeostasis, immune system, liver and bile function, gastrointestinal function and so on. The most important and explicit is the regulation of the TGR5 receptor for the homeostasis of blood glucose. The excitations of TGR5 on the intestinal secretory cells will promote G The secretion of.GLP-1 from LP-1, GLP-2 and PYY can promote insulin release of Blood Glucose dependent, inhibit appetite, slow down gastric emptying, and maintain the integrity of the blood glucose homeostasis.GLP-2 to maintain the integrity of the intestinal tract and promote the growth of intestinal tissue by.PYY to inhibit the appetite. Therefore, TGR5 agonists are potential drugs for anti diabetes and intestinal diseases. But TGR5 The excitant of the receptor on the gallbladder leads to the obstruction of the bile and the enlargement of the gallbladder. The development of the TGR5 agonist to target the intestinal tract may avoid the side effects of the bile filling. This article mainly designs the intestinal target TGR5 agonist based on the soft drug strategy. The B1 structure of high in vitro activity was optimized and then the ester compound B12a was finally found, which could be metabolized in plasma into a low active carboxylic acid B13a. in order to accelerate the plasma metabolic rate of the compound. By removing the chlorine atoms from the B12a benzofuran ring, the ester base site was replaced to the higher active ester, and the pyridine ring position was changed. C1g, C1i and other compounds have good extracorporeal and plasma metabolic rates. In oral administration, C1g, C1i in plasma, gallbladder, and bile are very low. In contrast, it is in ICR mice for three days or in db/db mice for four days in a large dose trial, C1g, C1i did not show obvious bile filling side effects. The systematic study also showed that the faster the plasma metabolism rate of the compound, the lower the exposure in the body, the weaker the side effect of the gallbladder. In the single oral OGTT test of ICR mice, C1g and C1i showed significant hypoglycemic activity. And the series of compounds were 0.25% of CMC used in the matching of samples. The stability in the simulated gastric juice of the -Na water solution and P H 1.2 meets the needs of the body test. The above test shows the feasibility of using the soft drug strategy to target the intestinal TGR5 agonist. But C1g, C1i still has some defects, one is that the Caco-2 cell permeability of C1g and C1i is not low (Papp is about 1 x 10-6 cm/s); two is in the drug test in vivo, The concentration of the two compounds in the intestinal tissue is not high enough. From the angle of improving the polarity of the compound, it is hoped to reduce the cell permeability of these soft compounds and increase the concentration of the compounds in the intestinal tissue. It was found that D5g of pyridine nitrogen atoms modified to quaternary ammonium salt had good in vitro activity of H TGR5, rapid plasma metabolic rate, and very low permeability of Caco-2 cells, Papp was only 0.01 x 10-6 cm/s., but the activity of D5g and similar compounds in vitro had significant differences in species genera, and this species was partly derived from benzofuran. Therefore, C1g, C1i analogues and D5g analogues were designed to ring the benzofuran ring of D5g analogues, and D7j, D7l and D9m.D7j, D7l and C1g, and C1i activity was close, and the rate of hydrolysis in plasma was faster. The difference in the activity of D9m in vitro was relieved, and the difference was only 5.9 times. The only activity of the pyridine quaternary ammonium salts can reach the level of several hundred N M. On the other hand, reducing the water solubility of the compound can also significantly reduce the absorption of the compound. The chain structure and ring may increase its lattice energy and reduce the water solubility. Meanwhile, the ring strategy can also increase the novelty of the compounds, which is beneficial to the patent protection in the later period. On the basis of A21a and B1, this paper preliminarily found that the substituted benzo and nitrogen heterocyclic compounds have medium extracorporeal activity through the optimization of the annulus and the initial structure-activity relationship, and the best compound is E5c..

【学位授予单位】：中国科学院大学(中国科学院上海药物研究所)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R914;R96
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本文编号：1804172