Cordyceps sinensis, a well-known and valuable traditional Chinese medicine, is a composite consisting of the stromata of the fungus, Cordyceps sinensis (Berk.) Sacc. (Fam. Hypocreaceae) parasitized on the larva of some species of insects (Fam. Hepialidae), and the dead caterpillar. Cordyceps, sweet in taste and neutral in nature, is commonly used in hospitals and sold as health food products in China. However, the yield of the wild resources of Cordyceps sinensis is decreasing every year because of excessive collection. Due to pretty high values, isolation of mycelial strain from Cordyceps is a trend of many scientists to achieve a large scale production of Cordyceps by fermentation. Besides cultivation of Cordyceps, much effort has also been focus on discovering the alternative species, Cordyceps militaris is the most popular one. To date, nucleosides are believed to be the active components in Cordyceps. Adenosine is used as marker for quality control of Cordyceps sinensis recorded in China Pharmacopeia (2005). However, it is hard to control the quality of natural and cultured Cordyceps. Therefore, it is very important to elucidate the difference of nucleosides in Cordyceps (natural Cordyceps sinensis, cultured Cordyceps sinensis and Cordyceps militaris), which is beneficial for their quality control. The thesis consists of four chapters. Chapter 1 reviewed nucleosides in Cordyceps and analytical methods for nucleosides and analogous. Chapter 2 focused on qualitative and quantitative determination of nucleosides in natural and cultured Cordyceps using high performance liquid chromatography-electrospray ionization tandem mass spectrometry and PLE extraction. A simple and rapid HPLC-ESI-MS/MS method was developed for qualitative and quantitative determination of nucleosides, bases and their analogues in natural and cultured Cordyceps. The results showed that 43 compounds, including 27 unknown compounds, as well as cytosine, uracil, cytidine, hypoxanthine, guanine, uridine, thymine, adenine, inosine, guanosine, thymidine, adenosine, cordycepin, 2'-deoxyadenosine, 6-hydroxyethyl-adenosine and 3' - amino-3°-deoxyadenosine were identified in natural and cultured Cordyceps. Especially, cordycepin was contained both in natural Cordyceps sinensis and cultured Cordyceps militaris, while 2'-deoxyadenosine was mainly contained in natural and cultured Cordyceps sinensis. The contents of 13 nucleoside and bases in Cordyceps were determined using LC-MS. The amounts of adenosine, guanosine, uridine in cultured Cordyceps sinensis are higher than those in natural Cordypes sinensis while the content of inosine is higher in natural Cordyces. The amount of cordycepin is pretty high in Cordyceps militaris. Though, the total amounts of nucleosides in natural Cordyces sinensis are lower than those in cultured Cordyceps. Adenosine, inosine and cordycepin could be used as markers for quality control of Cordyceps. Chapter 3 showed the comparison of total bio-available nucleosides in Cordyceps using perchloric acid hydrolysis followed with HPLC-DAD. Chapter 4 was a summary for the study.

冬蟲夏草是名貴的傅統中藥，爲奇生在蝙蝠蛾科昆蟲幼蟲上的子座及幼蟲屍體的複合體。由於冬蟲夏草具有重要的食用與藥用價值，野生資源被極度探集致使資源愈來愈少。近年來，人工冬蟲夏草深層發酵代用品和人工北冬蟲夏草的研究取得較大進展，相繼研製成功了一些發酵菌絲產品投放市場，使得現有市場上主要以這三種蟲草（天然蟲草，人工蟲草，人工北蟲草)爲主。本專題主要針對目前冬蟲夏草的品質控制標準評價方法上的不足：現有品質標準（中國藥典 〈2005 年版〉以腺苷爲指標）去評價天然蟲草，目前市場上天然與人工蟲草混淆不清，人工蟲草產品之間品質參差不齊，產品良莠不分。去尋找到相對科學的整定、誑 價天然和人工蟲草的方法就顯的尤爲重要。 爲此，我們探取了比較學的研究思路。利用不同的分析方法，從不同的角度去比較天然、人工蟲草的核苷類成分。我們首先探用了高效液相色譜-質譜聯用 技術(HPLC-MS/MS)方法，對蟲草的核苷類成分進行定性分析，同時對 13 種核苷及其城基進行定量分析，確證了以肌苷、腺苷、蟲草素爲特徵性成分的，能有效鑒定三種蟲草的方法。並關明瞭蟲草素在天然和人工蟲草中的分佈特徵。然後，我們針對在核苷類成分分析中人工蟲草的核苷含量要高於天然蟲草的核苷含量，而天然蟲草的核苷含量隨貯存時間延長和條件的變化會增高的，人工盡草則 沒有變化的現象，從理論上分析了天然蟲草的核苷含量的增高可能來源於核(酸） 苷等大分子的降解，並進一步比較了天然和人工蟲草的生物可吸收的核苷類成分。利用基於酸解法和 HPLC 的方法測定嘌呤堿基、嘧啶城基的含量方法，分析天然、人工蟲草的總潛在(可吸收)核苷類成分的不同。 全交共分四章，第一章是有關核苷分析方法研究的交獻綜述，對目前核苷分析方法作一總結，並探討了這些分析方法在中藥核苷成分的應用前景以及三種蟲草的研究介紹和核苷研究在蟲草品質控制中的地位概況。第二章是本研究的重點建立了高效液相色譜-質譜聯用技術(HPLC-MS/MS)定性、定量測定天然和人工蟲 草不同的核苷類成分的方法，聞明瞭中藥冬蟲夏草的蟲草素在天然和人工蟲草的存在特徵，證實了天然和人工蟲草中的一些核苷類似物的存在，測定冬蟲夏草中 13 種核苷成分含量；第三章是利用高氯酸酸解蟲草總潛在(可吸收)核苷，基於 HPLC-DAD 的方法測定嘌呤城基、嘧啶城基的含量，比較了三種冬蟲夏草生物 總潛在(可吸收)核苷類成分化學成分含量差異，建立了一個可行的利用 HPLC定量城基去測定生物可吸收的核苷方法。第四章是研究結果的分析和總結，進一步比較分析了天然蟲草和人工蟲草的異同以及評價核苷在蟲草品質的地位。 關鍵宇：核苷，生物可利用，蟲草，HPLC-MS/MS，酸水解