地骨皮中新颖酰胺类生物碱的发现及其降血脂活性研究

hyperlipidemia is the major risk factor for atherosclerosis and other numerous cardiovascular diseases. Several commonly used antihyperlipidemic drugs in clinic are having various side effects. Thus,there is a considerable need for the development of new antihyperlipidemic bioactive compounds. Cortex Lycii, the root bark of Lycium chinense, belongs to family of Solanaceae. In our recent studies revealed that its ethanol extracts and active fractions showed strong hypolipidemic effect, and seven amide alkaloids have been isolated from the active fractions, including three new ones; two of which displayed significance hypolipidemic activities both in vitro and in vivo. Preliminary mechanism research indicates that the amide alkaloids can increase the activation of AMPK signal path in HepG2 cells. In this proceed project, we will utilize modern chromatography techniques to study the hypolipidemic chemical components of Cortex Lycii. More than thirties amide alkaloids will be isolated from the other active fractions guided by chemical screen and combianation of multiple chromatography technique, and their structures will be elucidated on the basis of physicochemical properties and spectral methods . The hypolipidemic activities of these compounds will be evaluated by HepG2 cell lipid accumulation bioassay and hyperlipidemia mouse model experiments, and also the preliminary structure activitiy relationships between them will be discussed. Then chose promising compounds to investigated the molecular mechanism of hyperlipidemia. The resultsof this project will provide a scientific basis for the development of innovation drug for treatment of metabolic disorders in hyperlipidemia.

高血脂症是诱发动脉粥样硬化等众多心血管疾病的重要影响因素。目前临床常用的降脂药物多数具有毒副作用，因此继续寻找和发现新的降血脂活性成分具有重要意义。前期研究表明地骨皮（茄科植物枸杞的干燥根皮）醇提物及其有效部位具有较好的降血脂活性，并从活性部位中分离得到7个酰胺类生物碱，包括3个新化合物，其中2个化合物在体内外显示出显著的降血脂活性并可通过激活腺苷活化蛋白激酶（AMPK）起到降脂作用。本课题拟在此基础上通过多种色谱技术结合的化学筛选和分离手段，针对性地获取剩余活性组分中的30余种酰胺类生物碱并鉴定其分子结构。采用HepG2细胞脂质堆积模型和高血脂小鼠模型对预期分离得到的单体酰胺类生物碱进行体内外活性评价，确定降血脂活性成分，并初步探讨其构效关系。在此基础上，优选出活性显著、结构新颖的化合物，对其降血脂作用的分子机制进行初步探讨，以期为寻找治疗高血脂症脂质代谢紊乱的药物提供科学依据。

本项目共从地骨皮降血脂有效部位中分离得到45个化合物，其中生物碱类化合物21个，酚酸酯及其苷类化合物24个，新化合物共11个，包括7个结构新颖的酰胺类生物碱。对其中的32个化合物（包括17个酰胺生物碱和15苷类化合物）进行了体外降脂活性评价。药理研究结果显示，有12个化合物（7个酰胺生物碱、5个苷类）在10微摩尔浓度下能够显著降低HepG2细胞内的脂质堆积水平，并呈现一定的构效关系。在降低TG方面，2个酰胺生物碱（化合物7和8）、2个苷类（化合物30和31）的活性略强于阳性对照药辛伐他汀。利用急性高脂血症KM小鼠模型对4个降脂活性显著且含量较大的酰胺类生物碱（7, 8, 12, 15）进行了体内实验验证，结果显示化合物7和8在降低小鼠血清TC或TG水平方面略强于阳性对照药辛伐他汀或与阳性药相当。对7和8进行了初步的降脂作用机制研究，结果发现这2个化合物在1-10微摩尔浓度下可显著改善HepG2细胞脂质代谢，其中在10微摩尔浓度下最为显著，并可通过调节脂代谢相关蛋白p-AMPK、SIRT1、FOXO1和线粒体氧化相关因子发挥调血脂作用。.该项目目前已在Fitoterapia、Natural product research等SCI期刊发表论文2篇，在中草药杂志发表论文1篇，发表会议论文1篇，培养本科毕业生4名，申请国家发明专利1项（No:201711023299.2）。.