葛根、大黃、地黃之定性、定量分析與數據化指紋圖譜研究

Abstract

高效液相層析（HPLC）是最常用來測定中藥成分含量的分析方法，而對於不具UV吸光團的化合物，則以HPLC與ELSD、質譜儀連線偵測，合併運用各種偵測器的優點，可以拓展中藥化學評價的範疇。

本研究計分五部分，第一部分為葛根藥材的LC-MS分析及葛根藥材的化學基原鑑別。葛根是豆科植物（Leguminosae）甘葛藤(Pueraria lobata Ohwi.)的乾燥根，為重要的解表藥材，主要含異黃酮類化合物。本研究利用LC-MS連線偵測，能對十二個指標成分同時完成分離及鑑定；歸納這些指標成分的斷裂方式，可以建立一套適用於異黃酮類化合物的鑑別規則，並推測未知的化合物結構。市售葛根藥材有野葛與粉葛兩種，本研究以統計軟體搭配各種不同的數據處理方式，完成葛根藥材之數據化指紋圖譜分析。

第二部分為大黃藥材的LC-MS分析及大黃藥材的化學基原鑑別。大黃(Rhei Rhizoma)為蓼科植物的乾燥根莖，是重要的瀉下藥材，含有anthraquinones，dianthraquinones，stilbenes，galloylglucoses等多種組成成分，本研究利用LC-MS連線偵測，能對十九個指標成分同時完成分離及鑑定；而判讀TIC圖中未知波峰之MSn質譜圖之斷片資訊，與先前文獻比對，可以推測出其結構。市售大黃有唐古特大黃、掌葉大黃、馬蹄大黃三種，利用圖形辨識技術以及數據化指紋圖譜分析，可以完成三品種之化學基原鑑別。

第三部分為地黃藥材HPLC-UV-ELSD之分析方法開發及生地黃與熟地黃之化學鑑別，本論文並探討地黃炮製之藥理意義，及不同炮製方法導致的差別結果。地黃中的主要成分是醣類，利用Hypercarb porous graphite材質管柱並褡配ELSD偵測器，使用0.1%甲酸及甲醇為沖提液，可以於六十分鐘內對地黃中的醣類成分完成分離並定量。實驗數據顯示，地黃在炮製過程中，醣類成分會有大幅度轉變，因此本文利用其主成分mannintriose與stachyose的積分面積比例關係，區辨生地黃與熟地黃。

梓醇(catalpol)是降血糖的藥理活性成分，但是在炮製過程中遭到破壞，顯然熟地黃的藥理作用應不同於生地黃。本研究發現，地黃在炮製過程中有梅納反應（Maillard reaction）發生，反應的中間產物5-HMF，有醛糖還原抑制劑（ARI，Aldose reductase inhibiotor）之藥理活性作用；反應的終產物類黑色素（melanoidins）及寡糖成分，具有活化腸內益生菌、降低膽固醇、調節免疫、抗氧化及促進礦物質吸收等機能，顯示生地黃與熟地黃有不同的療效。本研究分別炮製多批地黃樣品，以研究不同炮製時間、次數、伴蒸溶液的差異，結果發現以每蒸三小時，九次蒸曬的樣品最佳；蒸製時，添加酸性物質，有催化醣類轉變與5-HMF生成的效應。

第四部分為微量元素分析，分析葛根藥材中野葛與粉葛在微量元素組成上的差異，以及地黃各階段炮製品的微量元素含量。實驗結果顯示，野葛與粉葛的微量元素含量組成的有差異，粉葛中重要的微量元素要比粉葛為高；取地黃的炮製樣品作微量元素分析，發現多數元素含量隨蒸曬次數的增加而遞減，但如Fe、Zn、Mn、Co、Ga、Sr、Ba、Ni等少數元素卻見反向增加。

第五部分為杏仁與地黃之胺基酸組成成分分析。胺基酸為不具UV吸光且極性極高的成分，本研究採用Waters 新開發之AccQ-Tag衍生試劑進行柱前衍生反應，得到穩定的衍生化產物，再用逆相層析法完成分析以及定量。實驗結果發現，杏仁藥材中主要含有十八種胺基酸，且其含量苦杏仁遠高於甜杏仁；地黃藥材中含有十七種胺基酸成分，生地黃中含量遠高於熟地黃。

High-performance liquid chromatography (HPLC) is the most commonly used instrument for analyzing the components in Chinese herb medicine. As for compounds which do not have any UV absorption group, ELSD or mass spectrometer coupled HPLC is used for analysis. Advantages of each instrument are combined to expand the chemical evaluation of Chinese herb medicine.

There are five parts in this study. The first part is the LC-MS analysis and plant origin identification of Puerariae Radix, which is dry roots from Leguminosae Pueraria lobata Ohwi. Puerariae Radix is an important Chinese herbal medicine to expel superficial evils. Its major components are isoflavones. LC-MS was used in this study to separate and identify 12 marker compounds simultaneously. From the fragmentation patterns of these marker components, a rule for identifying isoflavones can be established, and structure of unknown compounds can be predicted. Two kinds of Puerariae Radix are available on the market, P. lobata Ohwi and P. thomsonii Benth. In this study, fingerprint analysis of Puerariae Radix was accomplished using the statistical software with other data processing methods.

The second part is the LC-MS analysis and plant origin identification of Rhei Rhizoma, which is dry roots and stems from Polygonaceae plants. Rhei Rhizoma is an important purgastive herbal medicine. Its components include anthraquinones, dianthraquinones, stilbenes, and galloylglucoses. LC-MS was used in this study to isolate and identify 19 index components simultaneously. Comparing the fragments of MSn mass spectra in the TIC diagram from unknown peaks with previous reports, their structure can be predicted. Three kinds of Rhei Rhizoma are available on the market, Rheum tanguticum Maxim, Rheum palmatum Linne, and R. officinale Baillon. Plant origin identification of three species was accomplished using graphic identification technology and HPLC fingerprint analysis.

The third part is the development of analytical method for Rehamnnia with HPLC-UV-ELSD and chemical identification of Rehmanniae Radix and Rehmanniae Preparata Radix. Pharmacological significance of processing and different results from various processing methods for Rehamnnia were discussed in this study as well. The major components of Rehamnnia are saccharides. With a mobile phase of 0.1% formic acid and methanol, a Hypercarb porous graphitic column, and an ELSD detector, saccharides in Rehmanniae were isolated and quantitatively analyzed. Results showed that carbohydrates in Rehmanniae are much different after processing. Therefore, the peak area ratio of mannintriose and stachyose, which are the two major components of Rehmanniae, was used to differentiate Rehmanniae Radix and Rehmanniae Preparata Radix.

Catalpol is the active ingredient to decrease blood sugar. It is destroyed during the processing. Therefore, the pharmacological reactions of Rehmanniae Preparata Radix are different from Rehmanniae Radix. It is also found that Maillard reaction occurs during the processing of Rehmanniae. The intermediate product, 5-HMF, has the activity of Aldose reductase inhibiotor (ARI). The end products, melanoidins, and oligosaccharides have the functions to activate intestinal probiotics, decrease cholesterol, regulate immunity, increase anti-oxidation, and increase the absorption of minerals. This also shows that clinical effects of Rehmanniae Preparata Radix are different from Rehmanniae Radix. In this study, several groups of samples from Rehmanniae were prepared to study different results due to various time of processing, frequency of processing, and incubation solutions. It was found that sample which was steamed 3 hours and dried for 9 cycles is the best. Addition of acidic substance during processing increased the conversion of 5-HMF from saccharides.

The fourth part is the analysis of trace elements. The content of trace elements in P. lobata Ohwi and P. thomsonii Benth, and the contents of trace elements in different stages of processing of Rehamnnia were analyzed. Results showed that the elemental profile of P. lobata Ohwi and P. thomsonii Benth are somewhat different. P. thomsonii Benth contains higher amount of important elements than P. lobata Ohwi. As to Rehamnnia, most elements decrease with number of processing cycles increase. However, some elements such as Fe, Zn, Mn, Co, Ga, Sr, Ba, Ni increases.

The last part is the analysis of amino acids in almond seeds and Rehamnnia. Amino acids do not have characteristics of UV absorption, and they are very polar molecules. In this study, AccQ-Tag reagent, which is a newly developed derivative reagent by Waters, was used to perform a pre-column derivative reaction. The stable derivative products were then analyzed quantitatively by reverse phase HPLC. It is found that there are 18 kinds of amino acids in seed of P. armeniaca L.var. ansu Maxim sample. The content in P. armeniaca L.var. ansu Maxim is much higher than Prunus armeniaca L. There are 17 kinds of amino acids found in Rehamnnia. The content in Rehmanniae Radix is much higher than Rehmanniae Preparata Radix.