【作者】 周安；

【导师】 潘见；

【作者基本信息】 合肥工业大学 ， 农产品加工及贮藏工程， 2015， 博士

【摘要】 血管性痴呆(Vascular Dementia, VD)是指因各种脑血管疾病所致的严重认知功能障碍的临床综合症。随着社会老年化速度的加快,我国已成为全世界老年人口数量最大的国家,统计显示我国60岁以上老年人VD的患病率为1.1～3.0%,且呈逐年上升的趋势。作为脑血管病的主要并发症,VD给患者的身心健康带来严重危害,同时也给患者家庭带来了很大的精神压力和经济负担,受到国内外学者及社会的极大关注。VD的发病机制复杂,其临床有效治疗需针对三类靶点：通过抗血小板聚集改善大脑供血、供氧;抑制乙酰胆碱酯酶(AChE)改善认知；保护神经元。现有的VD治疗药多为单靶点药物,临床上难免联合用药；然而,多药联用往往存在相互作用、药物代谢动力学参数改变、毒性等不确定因素,因此,创制多靶点VD治疗药物尤显必要。临床报道,一些天然药物能改善脑血管供血供氧和保护神经元,但抑制AChE活性欠缺；作者选择药效肯定的丹皮酚和川芎嗪等小分子天然药物为母核进行结构修饰,以期基本保持原有药效,增强AChE抑制活性,创制三靶点VD治疗药物。研究结果如下：1.设计、筛选和合成出10个具AChE抑制活性的目标化合物。以丹皮酚、川芎嗪等为母核,设计得92个AChE抑制剂。另选90种已知AChE抑制活性的化合物,以CoMFA描述符为自变量,p1C50值为因变量,构建3D-QSAR活性预测模型；72个训练集分子和18个外部测试集分子的p1Cso实验值和预测值显示该模型预测能力良好。以该模型对设计的92个化合物进行活性预测和筛选,其中10个较优,进而完成这10个化合物的化学合成和结构确证。2.体外活性筛选表明化合物11更具AChE抑制、抗血小板聚集和神经元保护活性。对合成的10个化合物进行体外活性试验,比较AChE抑制、抗血小板聚集和神经细胞保护作用,发现化合物11(PT-11)最佳。PT-11的AChE抑制活性达到纳摩级(IC50=0 .24μmol·L-1);其浓度为100 μmol·L-1时对血小板的抑制率为85.58%,强于阳性对照药阿司匹林(81.47%)、丹皮酚(51.68%)和川芎嗪(72.80%)；浓度为40μmol·L-1时对H202损伤的PC12细胞保护的增殖率为85.24%,优于丹皮酚(61.45%)和川芎嗪(67.29%)。3.动物试验确认PT-11具AChE抑制、抗血小板聚集和神经保护三靶点药效。采用双侧颈总动脉永久性结扎法制作VD大鼠模型,考察了PT-11对VD模型大鼠的保护作用。结果表明,PT-11可显著改善VD模型大鼠的神经功能缺陷和学习、记忆能力。PT-11可通过抑制血小板聚集,改善缺血造成的病理损伤,减轻海马锥体细胞受损程度,保护脑神经元；提高海马组织中的SOD活性,降低MDA含量减轻脂质过氧化损伤；降低海马AChE活性,提高ACh含量来改善模型大鼠的学习记忆能力。相对于阳性药多奈哌齐,PT-11呈现了三靶点的治疗优势。更多还原

【Abstract】 Vascular Dementia (VD) is defined as a loss of cognitive function resulting from ischemic or hemorrhagic brain lesions due to various cerebral vascular diseases. With the acceleration of aging society, China has become the largest country in the number of elderly population all over the world. The prevalence of VD has reached 1.1～3.0% in elderly people over the age of 65 years, and the trend is still rising year by year. As the major complication of cerebrovascular disease, VD severely threaten physical health and life quality of the patients. It also bring a heavy burden of the society and family, which has got much attention these years.Duo to the complicated pathogenesis, the therapy of VD is usually aimed at three targets:anti-platelet aggregation; anti-acetylcholinesterase (AChE) and neuron protection. The therapy of anti-platelet aggregation can increase blood flow and improve cerebral oxygen in brain; anti- AChE and protection of neurons can improve the function of cognition. Nowadays, numerous medications were used to treat VD, but the curative effect is not so good for the reason of single-target drug of these medicines, especially for the serious patients. So combination of the drugs is normally used in clinical treatment, but it has the risk interactions with other medication, bioavailability, pharmacokinetics, toxicity, etc. So it is necessary to develop new multiple-targets drugs for the treatment of VD.According to the theory of Traditional Chinese Medicine and a variety of clinical reports, some natural medicines can increase blood flow, improve cerebral oxygen in brain and protect neurons, but without the effect for anti-AChE. In this study, paeonol and ligustrazine as lead compounds were modified to synthesis novel three-targets drugs for the treatment of VD. The results are listed as follows:1. Ten novel AChE inhibitions were firstly synthesized through rational drug design and structure-based virtual screeningBy using paeonol and ligustrazine as lead compounds,92 AChE inhibitions were designed. To predict the AChE inhibitory activities of these compounds, three dimensional-quantitative structure activity relationship (3D-QSAR) studies were performed on 90 AChE inhibitions with known AChE inhibitions abilities. The comparative field analysis (CoMFA) model with CoMFA descriptors as variables and the half maximal inhibitory concentration (pIC50) as the dependent variable. Statistical results indicate that this model has satisfactory residual values for the training set and test set and will be useful to predict the biological activity of the potential drugs. According to the CoMFA model, the inhibitory activities of 92 AChE inhibitions were predicted. Finally, ten new compounds were synthesized, which were predicted with great AChE inhibitory activity by using the 3D-QSAR CoMFA model.2. Compound 11 showed stronger biological activities for; and neuron protection.The synthesized 10 compounds were investigated by anti-AChE activity, anti-platelet aggregation activity and the ability of neuron protection. Biological assays revealed that compound 11 has strong AChE inhibition property, with IC50 values to sub-micromolar (IC50=0.24 μmol·L-1). It also showed potent inhibitory activity against platelet aggregation (in vitro). The inhibitory rate of blood platelet was 81.47%, administering at the dosage of 100 μmol·L-1, which better than aspirin (81.47%), paeonol (51.68%) and ligustrazine (72.80%). It also could significantly inhibit hydrogen peroxide-induced neuronal PC 12 cell death assessed by MTT assay. In the concentration range of 40 μM, the proliferation rate of PC 12 cell was 85.24%, which better than paeonol (61.45%) and ligustrazine (67.29%).3. The biological activities for; and neuron protection of compound 11 were futher confirmed by animal experiments.Model of Vascular Dementia in rats were induced by ligating bilateralcommon carotid artery (2-VO).The therapy effect of compound 11 was evaluated the morphological changes of CA1 hippocampal area, the content changes of ACh adn MDA, the activities of AChE and SOD, and the activity of anti-platelet aggregative. The results shown that the learning and memory abilities of VD model rats could significant improved by treating compound 11. It had inhibitory activity against platelet aggregation and neuroprotective effects on the area of hippocampal CA1. Further experiments proved that it could significantly enhance the activities of AChE and SOD, reduce the content of ACh adn MDA. Compare to positive control group (Donepezil), compound 11 has advantage for multi-targets.更多还原