淫羊藿炮制的物质基础与药效变化机理研究

Herba Epimedium has been used in traditional Chinese medicine (TCM) as a tonic, antirheumatic and aphrodisiac. Previous chemical and pharmacological investigations on Epimedium have showed that the major bioactive constituents are prenylflavonoids. Traditionally, herba Epimedium is processed by heating with sheep fat to enhance sexual function, and anti-inflammatory action, but the material basis and mechanism of pharmacodynamic change are unclear. On the basis of previous work, we found that it may be relevant to 8-isopentene group double bond addition, isomerism and condensation with 7-hydroxyl as furan or pyran ring on processing. This project intends to research the transformation during the processing process of prenylated flavonoids which are the main active ingredients of Epimedium. The composition and content of flavonoids in processed products obtaining by various processing methods will be determined, together with the separation of characteristic constituents and new constituents emerged during the processing process. Moreover, the transformation mechanism of chemical composition before and after the processing process is going to be discussed by synthesising 8-prenylated compounds by a variety of reactions, such as hydrolysis reaction, addition reaction and radical reaction, which simulate processing process. It provide a scientific basis for the optimization of the processing process of Epimedium, perfection of the herbal pieces quality standards, and the safety, activity, rationality of clinical drug selection.

淫羊藿是我国传统补益中药，其饮片生用与制用功效迥异，生品主要用于祛风湿、强筋骨，炮制后增强温肾助阳的作用，但其炮制的物质基础及药效改变的机理尚不清楚。在前期工作基础中发现可能与炮制过程中8位异戊烯基双键加成、异构、以及与7位羟基缩合成呋喃/吡喃环有关。因此本项目拟以淫羊藿的主要活性成分异戊烯基黄酮类化合物在炮制过程中的转化为研究目的，以淫羊藿饮片、异戊烯基总黄酮和单体成分为研究对象，采用不同炮制工艺，检测各炮制品中黄酮类成分的组成和含量，寻找转化产生的新成分和特征差异性成分。并以水解、氧化加成、自由基反应等化学方法模拟炮制过程，合成8位异戊烯基的转化产物，探讨炮制前后化学成分的转化机理。结合对细胞因子水平的影响，分析炮制前后的药性和药理活性变化，从分子水平阐明淫羊藿油炙的炮制机理。为淫羊藿炮制工艺的优化、饮片质量标准的完善、以及淫羊藿饮片临床用药的安全、有效和合理性提供科学依据。

淫羊藿（EPIMEDII FOLIUM）是我国的传统中药，具有补肾阳，强筋骨，祛风湿的功效，且其有生炙异用的特性，生品主要用于强劲健骨，炮制品主要用于温肾助阳，可能原因是淫羊藿在炮制过程中物质基础发生变化，例如糖苷水解、氧化、异戊烯基成环、以及炮制辅料对其化学成份影响。. 为了进一步探明淫羊藿生品和炮制品化学成分的差异，对淫羊藿炮制品及其生品进行了系统的化学成分研究。从朝鲜淫羊藿炮制品中共分离鉴定了24个化合物，其中3个为新化合物；从朝鲜淫羊藿生品中共分离了26个化合物，其中1个为新化合物。研究表明，淫羊藿的炮制品与生品相比，水溶性部分异戊烯基黄酮变化不大，而脂溶性部分化学成分差异较大，可能是淫羊藿药用功效差异的原因。. 淫羊藿原药材中的异戊烯基黄酮类以配糖体形式存在，口服后代谢为苷元吸收，因此对淫羊藿总苷的水解方法进行了探索及条件优化，制备得到淫羊藿素、脱水淫羊藿素。淫羊藿炮制过程中异戊烯基黄酮类成分可能发生了氧化、环合等反应，通过体外化学合成方法模拟炮制过程，以淫羊藿素、脱水淫羊藿素为原料，制备得到3,5,7-trihydroxy-8-(3-hydroxy-3-methylbutyl)-2-(4-methoxy phenyl)-4H-chromen-4-one、3,5,7-trihydroxy-2-(4-methoxyphenyl)-8-(3-methylbut-2-en-1-yl)-4H-chromen-4-one、3,5-dihydroxy-2-(4-methoxyphenyl)-8,8-dimethyl-9,10-dihydropyrano[2,3-f]chromen-4(8H)-one，证实炮制中异戊烯基黄酮变化的可能性。首次发现炮制辅料羊脂油在淫羊藿炮制过程中可与异戊烯基黄酮成酯，模拟合成得到3,5-二乙酰氧基脱水淫羊藿素、3,5-二油酰氧基脱水淫羊藿素、3,5-二棕榈酰氧基脱水淫羊藿素、3,5,7-三乙酰氧基淫羊藿素、3,5,7-三油酰氧基淫羊藿素、3,5,7-三棕榈酰氧基淫羊藿素。抑制V型磷酸二酯酶(PDE5)酶活性可升高cGMP水平，从而达到治疗ED的目的。通过PDE5A1试剂盒测试了炮制前后主要特征化合物的抑制生物活性，发现淫羊藿素、脱水淫羊藿素与羊脂油发生酯化的反应产物其活性与西地拉菲相当。阐明淫羊藿炮制前后的主要化学成分药理活性差异。