【作者】 于晓宇；

【导师】 郑锦鸿；

【作者基本信息】 汕头大学 ， 药物化学， 2009， 硕士

【摘要】 研究背景据报道,查尔酮类化合物具有抗肿瘤、抑制和清除氧自由基、抗菌、抗病毒、抗寄生虫、抗胃溃疡及抗过敏等多种药理活性。然而,相关文献报道较多集中在人工合成查尔酮的合成工艺讨论,抑或具有查尔酮结构的天然植物提取物的药理活性分析,而对于查尔酮及其类似物构效关系的阐述则并不多见。据报道,具有酚结构的羟基查尔酮类化合物具良好的抗氧化、清除自由基等药理作用,可有效抑制化学诱导剂缩氨酸、酵母聚糖调理素、大戟二萜醇氨基苯二酰肼醋酸酯等三种刺激物刺激多形核白细胞释放氧自由基。在本研究中,拟合成一系列羟基查尔酮类似物,并对其进行体内体外抗自由基活性测试,试图发现该类化合物活性构效关系以及具有优良抗自由基活性的新结构。研究目的发现羟基查尔酮类化合物抗自由基活性构效关系以及具有优良抗自由基活性的新结构。研究方法①合成部分以羟基苯甲醛类似物和羟基苯乙酮类似物为原料、以哌啶为催化剂,通过Claisen-Schmidt反应得到羟基查尔酮类似物。②药理部分用邻二氮菲-Fe2+氧化法测定羟基查尔酮类似物清除羟自由基（·OH）的活性,用DPPH法中的静力学法测定其清除1,1-二苯基苦基苯肼自由基（DPPH? ）的活性,通过超氧化物歧化酶（SOD）、丙二醛（MDA）、谷胱甘肽过氧化物酶（GSH-PX）水平测试考察东莨菪碱所致阿尔茨海默病小鼠脑组织过氧化损伤的保护作用。研究结果①合成部分合成出9个羟基查尔酮类似物,分别为乳白色、黄色或橙色晶体,结构均经IR、1H-NMR、MS分析确证。②药理部分在体外抗自由基活性测试中,C₁、C₂、C₃、C₄、C₅、C₇、C₈、C₉清除DPPH?的IC₅0分别为2.1928 mmol/L、6.3533 mmol/L、1.8967 mmol/L、5.7809 mmol/L、0.5623 mmol/L、0.2344 mmol/L、0.2339 mmol/L、0.2547 mmol/L,其中C₆无清除能力,C₂、C₄清除能力较弱,C₁、C₃、C₅清除能力尚好,而C₇、C₈、C₉清除能力较优,在较高浓度下清除率可达90%以上,几与阳性对照药VC（IC₅0=0.2234 mmol/L）相当。C₁、C₂、C₃、C₄、C₅、C₇、C₈、C₉清除OH?的IC₅0分别为2.1429 mmol/L、4.5709 mmol/L、4.8641 mmol/L、10.2565 mmol/L、0.9528 mmol/L、0.4721 mmol/L、0.4634 mmol/L、0.5129 mmol/L,其中C₆无清除能力,C₄清除能力较弱,C₂、C₃次之,C₁、C₅清除能力尚好,而C₇、C₈、C₉清除能力较优,与阳性对照药VC相当（IC₅0=0.4550 mmol/L）。体内抗自由基过氧化损伤活性测试结果表明,化合物C₇、C₈可升高东莨菪碱所致阿尔茨海默病脑过氧化损伤小鼠全脑SOD（P<0.05）、GSH-PX水平（P<0.05）,降低MDA水平（P<0.05）。结论①找到一步法合成羟基查尔酮类似物的工艺。②发现各化合物OH·的清除活性与DPPH·自由基清除活性大小排序基本一致,这表明,羟基查尔酮类似物对两种自由基可能有着相同的清除机理。③发现以下构效关系:4位酚羟基邻位取代基类型与化合物抗自由基活性密切相关:邻位取代以供电子基团,活性明显增强;邻位取代以吸电子基团,活性明显减弱;且两边取代位点的取代基效应通常具有叠加性。④化合物C₇、C₈具有优良的拮抗东莨菪碱所致阿尔茨海默病小鼠脑过氧化损伤的作用,但并未得出相应量效关系。更多还原

【Abstract】 BackgroundChalcones are reported to be pharmacologically active in anti-cancer, anti-free radical, anti-bacteria, anti-virus, anti parasite, anti-gastric ulcer and anti-allergy. However, there are many references concerning the synthesis routes of chalcone derivatives or plant abstracts analysis containing them, rather than structure-activity relationship illustrations of a series of structurally identified chalcones. It is also reported that hydroxyl substituted chalcones, a kind of phenol, show capacities in anti-oxidation and clearing free radicals, some of which are released from polymorphonuclear leukocytes stimulated by peptide and zymosan opsonin. In this study, we attempt to synthesize a series of hydroxyl substituted chalcones and have further tests on their free radical-clearing activities in vivo and vitro, hoping to discover the structure-activity relationships of hydroxyl substituted chalcones and find out some new structures with high anti-free radical activities.ObjectiveTo discover the structure-activity relationships of hydroxyl substituted chalcones and find out some new structures with high anti-free radical activities.Methods①SynthesisTo synthesize a series of hydroxyl substituted chalcones via Claisen-Schmidt Condensation with hydroxyl substituted benzaldehydes and hydroxyl substituted acetophenones as reactants and piperidine as catalyst.②PharmacologyTo determine DPPH free-radical and OH free-radical clearing efficiencies via DPPH-Static Force Method and Ferrosin-Fe2+ Oxidation Method. To detect the influences of the compounds, whose activities excel the others in vitro-anti-free radical tests, on SOD, MDA , GSH-PX levels in whole brains of scopolamine induced-Alzheimer’s mice with peroxidation injuries. Results①SynthesisA series of hydroxyl substituted chalcones （C₁～C₉）were synthesized via Claisen-Schmidt Condensation with IR,1H-NMR,MS identifications. All of the compounds had a milk-white ,or yellow, or orange crystal appearance.②PharmacologyIC₅0 values of C₁～C₉ （except C₆）on DPPH free radical clearing were 2.1928 mmol/L、6.3533 mmol/L、1.8967 mmol/L、5.7809 mmol/L、0.5623 mmol/L、0.2344 mmol/L、0.2339 mmol/L、0.2547 mmol/L respectively and C₇、C₈、C₉ > C₁、C₃、C₅> C₂、C₄>C₆ , ranked by clearing-activity ,where C₆ hardly showed any activity and C₇、C₈、C₉ excel the others and are able to clear more than 90% DPPH free radicals in high concertrations with IC₅0 values similar to Positive Control Drug -VC（IC₅0=0.2234 mmol/L）; IC₅0 values of C₁～C₉ （except C₆）on OH free radical clearing were 2.1429 mmol/L、4.5709 mmol/L、4.8641 mmol/L、10.2565 mmol/L、0.9528 mmol/L、0.4721 mmol/L、0.4634 mmol/L、0.5129 mmol/L respectively and C₇、C₈、C₉ > C₁、C₅> C₂、C₃>C₄>C₆, ranked by clearing-activity ,where C₆ hardly showed any activity and C₇、C₈、C₉ excel the others with IC₅0 values similar to Positive Control Drug -VC（IC₅0=0.4550 mmol/L）;Results in vivo test of detections on SOD, MDA , GSH-PX levels in whole brains of scopolamine induced-Alzheimer’s mice with peroxidation injuries, revealed that C₇、C₈ are able to elevate Glutathione peroxidase （GSH-PX） （P<0.05）, Super Oxide Dismutase（SOD） （P<0.05）level and lower Malonaldehyde （MDA） （P<0.05）level in certain extents.Conclusion①A practical way to synthesize hydroxyl substituted chalcones was found.②The fact that the compounds showed similar rankings by activity in clearing DPPH-free-radical and OH-free-radical, demonstrated that hydroxyl substituted chalcones may clear these two kinds of free-radicals in similar mechanisms.③Structure-Activity Relationship illustrations: Anti-free radical activities varied a lot in hydroxyl substituted chalcones with different ortho-position-substitutions of 4- phenolic hydroxyls. Activities rose when an electron-donating-group substituted ortho positions of 4- phenolic hydroxyls while activities fell when an electron-withdrawing-group substituted ortho positions of 4- phenolic hydroxyls , and the two effects seem to stack when both ortho-positions were substituted.④Compound C₇、C₈ successfully antagonized peroxidation injuries of scopolamine induced-Alzheimer’s disease in mice brains, but no dose-effect relationships were found.更多还原