天然产物α-萜品烯醇的结构修饰及平喘活性研究

发布时间：2018-06-15 01:32

本文选题：支气管哮喘 + α-萜品烯醇　；参考：《浙江大学》2016年博士论文

【摘要】：支气管哮喘是由气道慢性炎症病变引起的支气管高反应性疾病,全球患者已达到3亿,它不仅严重影响人们的正常生活,严重的哮喘甚至威胁生命。迄今为止,哮喘尚无根治手段,只能采用症状改善药物进行治疗和预防,临床治疗主要采用支气管扩张药(β2受体激动剂为主)和抗炎药物(激素为主)的联合用药方案。β2受体激动剂对于危重哮喘患者存在一定程度的心功能损害,且与哮喘严重程度呈正相关,对于此类患者,联合用药方案会加大心衰的风险。因此,寻找和发现对心脏功能无影响、无激素类副作用的抗哮喘药物,将为患者提供新的选择,对于哮喘的临床治疗具有重要的价值。前期课题组发现天然产物单萜类化合物α-萜品烯醇对气管平滑肌有直接松弛的作用,且具有祛痰、镇咳、抗过敏等作用。但是α-萜品烯醇在艾叶中含量低,无法用水汽蒸馏法提取,药用来源受到限制,亟需采用新方法解决。另外,虽然α-萜品烯醇解痉作用好、起效快,但是其有效作用时间短(仅半小时左右)。因此,限制了该药物在临床中治疗哮喘的使用。针对药用来源受限的问题,本论文对αα-萜品烯醇的提取、分离方法进行研究,采用超临界CO2萃取与高速逆流色谱法分离相结合的方法,对艾叶中α-萜品烯醇进行分离纯化,成功获得90%以上含量的产物;另一方面,α-萜品烯醇的体内初步药代动力学研究表明,其半衰期T1/2约为2.148h,清除率为1.544L/h/kg,证明其口服吸收迅速、作用时间短是由于其药代动力学特性所致。针对α-萜品烯醇虽吸收速度快、但有效作用时间短的缺点,本文采用前药策略,对其结构中的羟基进行酯化修饰,设计、合成17个α-萜品烯醇酯类前药。另一方面,利用药物骈合原理,将具舒张支气管作用的NO供体片段亚硝酸酯(ONO2)引入α-萜品烯醇中,获得2个含有亚硝酸酯片段的α-萜品烯醇衍生物。此外,还合成了 α-萜品烯醇双键还原产物,初步探索烯烃片段对活性的影响。对上述合成的21个化合物进行豚鼠支气管平滑肌舒张试验。结果显示,有8个化合物显示出优良的舒张支气管平滑肌活性,优于阳性对照氨茶碱(舒张率45%)。特别是化合物6a和6d,在1.25mmol/l的浓度下,舒张率分别达到83%和85%。作用机制研究表明,6a、6b、6c、6d、6f、6g、6i等化合物对平滑肌细胞内cAMP含量有显著提升,提示该类化合物可能是通过增加细胞内cAMP含量来舒张支气管平滑肌,且与β2受体无关。MTT试验表明,在1.25mmol/L和0.625mmol/L浓度下,上述7个化合物对支气管平滑肌细胞增殖无明显影响。对高活性化合物6a,6d的体内初步药代动力学研究表明,化合物6a和6d的半衰期分别为2.309h和3.386h,较α-萜品烯醇的T1/2=2.148h有所提升,证明论文前药设计策略的合理性和可行性。进一步对化合物6a,6d开展整体动物平喘活性评价(大鼠哮喘模型),以肺功能、炎症因子IL-4,IL-17A等作为评价指标。结果显示,化合物6a,6d可通过提高哮喘鼠的气道顺应性和减少气道阻力,达到改善肺功能的效果,同时,可降低血清中的IL-4、IL-17A含量,抑制炎症,且对哮喘鼠的心率没有明显影响。因此,上述化合物显示出舒张支气管平滑肌和抗炎的双重活性,具有代替临床上β2受体激动剂和激素联合用药的潜力。
[Abstract]:Bronchial asthma is a bronchial hyperreactivity disease caused by chronic airway inflammation, and the global patient has reached 300 million. It not only seriously affects people's normal life, severe asthma and even life. So far, there is no radical cure for asthma. It can only be treated and prevented with symptoms modified by drugs. Clinical treatment is mainly used. A combined regimen of bronchiectasis (beta 2 receptor agonist) and anti inflammatory drugs (hormone based). Beta 2 receptor agonists have a certain degree of cardiac dysfunction in critical asthma patients and are positively related to the severity of asthma. For these patients, the combination regimen will increase the risk of heart failure. The antiasthmatic drug with no hormone side effects and no hormone side effects will provide a new choice for the patients. It is of great value for the clinical treatment of asthma. The previous research group found that the natural product monoterpenoid terpenoid enol has direct relaxation on the smooth muscle of the trachea, and it has the effect of expectorant, antitussive, and anti allergy. The content of alpha terpene enol in the leaf is low and can not be extracted by steam distillation. The source of medicine is limited and new methods need to be solved. In addition, although the effect of alpha terpenol enol is good and its effect is fast, its effective time is short (about half an hour). Therefore, it is limited to the use of the drug in the clinical treatment of asthma. In this paper, the extraction and separation of alpha terpene enol was studied in this paper. The method of supercritical CO2 extraction and high speed counter current chromatography was used to separate and purify the alpha terpene enol in the leaf. The product was more than 90%. On the other hand, the primary pharmacokinetics of alpha terpene enol in the body. The study shows that the half-life of T1/2 is about 2.148h and the clearance rate is 1.544L/h/kg. It is proved that its oral absorption is rapid and its action time is due to its pharmacokinetic characteristics. Although the absorption rate of alpha terpene enol is fast, but the effective time is short, this paper uses the prodrug strategy to modify the hydroxyl group in its structure. To synthesize 17 alpha terpene enol esters prodrugs. On the other hand, using the NO donor fragment nitrite (ONO2) with diastolic bronchodilation into alpha terpene enol, 2 nitrite enol derivatives containing nitrite fragments were obtained by the use of the principle of antipyrexia, in addition to the synthesis of alpha terpene enol double bond reduction products and preliminary exploration of alkenes. The effects of hydrocarbon fragments on the activity of the 21 compounds were conducted in guinea pig bronchi smooth muscle relaxation tests. The results showed that 8 compounds showed excellent diastolic bronchial smooth muscle activity, superior to positive control aminophylline (diastolic rate 45%), especially compound 6a and 6D, and the diastolic rate reached 83% at 1.25mmol/l concentration, respectively. 6a, 6b, 6C, 6D, 6F, 6G, 6I and other compounds have a significant increase in the content of cAMP in smooth muscle cells, suggesting that the compounds may be dilatation of the bronchial smooth muscle by increasing the intracellular cAMP content, and the.MTT test is not related to the beta 2 receptor. The preliminary pharmacokinetic study of high active compound 6a, 6D in vivo showed that the half-life of 6a and 6D compounds were 2.309h and 3.386h respectively, and the T1/2=2.148h of alpha terpene enol was improved, which proved the rationality and feasibility of the design strategy of the pre thesis. Further, 6D opened to compound 6A. The evaluation of the antiasthmatic activity of the whole animal (rat asthma model), with lung function, inflammatory factor IL-4, and IL-17A as evaluation indicators. The results show that compound 6a, 6D can improve the effect of lung function by improving airway compliance and reducing airway resistance in asthmatic rats. At the same time, it can reduce the serum IL-4, IL-17A content, and inhibit inflammation. The heart rate of the asthmatic mice is not significantly affected. Therefore, these compounds show the double activity of dilatation of bronchial smooth muscle and anti inflammation, which has the potential to replace the combination of clinical beta 2 receptor agonists and hormones.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R914;R96

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