台灣無患子皂苷元含量之研究

Abstract

近幾年來由於環保意識的興起，無患子(Sapindus mukorossi Gaertn.)的功用逐漸受到重視，除了可作為清潔劑之外，同時也具有療效。因此，尋找優良之無患子母樹變成重要的課題。 在本論文中，以外果皮中的皂苷元含量作為無患子優劣之指標。因此，在做各地無患子母樹採用了改良式的酸水解定量方法，此方法較傳統的香草醛硫酸法與粗皂素萃取更具有準確性。 而無患子母樹則採自台北芝山岩、台北八里、南投151縣道1公里與3公里處、台南大內鄉、台南左鎮三處、高雄、花蓮光復與林田山林業園區、台東東河鄉三處與大武鄉大鳥國小，共有16株不同的母樹，分別於2009年七到十月初進行採收，並進行皂苷元定量工作。結果顯示，各地無患子母樹在採收期間，其外果皮中的皂苷元含量均有上升趨勢，皆在七月份具有最低的皂苷元含量，而在十月份達到最大含量，除了在花蓮(東)之無患子外果皮中的皂苷元含量是於九月份達169.34 mg/g為最高，在十月份亦高達168.71 mg/g，其次為台南大內鄉於十月所採收的無患子外果皮皂苷元含量，達128.43 mg/g，與台南左鎮2的125.12 mg/g。無患子外果皮中的皂苷元含量最低的為位於花蓮(台糖)的此株母樹，其含量為52.55 mg/g。 為了解各個母樹之外果皮中最大皂苷元含量的差異與生長速度之不同，其影響的因素，本研究利用S型函數之三個係數、線性函數的各個係數，以及皂苷元最高含量作為自變數而土壤與環境因子作為應變數，其中土壤因子有土壤含水率、 土壤pH值、陽離子交換容量(CEC)、土壤中之電導度、有機質含量、有效性氮、有效性磷及交換性鈣、鎂、鉀； 環境因子有平均坡度、海拔、全年各地平均溫度、七到十月各地平均溫度、全年平均降雨量、七到十月之平均降雨量、七到十月總降雨量、森林面積與密度。藉由這兩個參數作Pearson’s correlation與線性迴歸(linear regression)來觀察其相關性並用R-square來作為相關程度的依據。結果顯示，土壤與環境因子，並未與皂苷元含量與成長速度的表現有直接的關係。根據此結果解釋，無患子母樹之個體差異，可能遠較於土壤與環境因子之影響來的大，而個體可能受到種源或基因等差異所影響。

In recent years, environmental consciousness is rising in Taiwan and people pay much attention to soapnut tree(Sapindus mukorossi Gaertn.) because of its functions. The soapnut trees can be cleaner and remedies in folk medicine. Therefore, screening superior germplasm resources of soapnut trees becomes an important issue. In this study, the sapogenins content in soapnut tree pericarp was adopted to be the index of soapnut mother trees quality. Hence, we used modified hydrolysis method to quantify fifteen mother trees around Taiwan. This method is more specific and accurate than vanillin sulfuric acid assay and organic extract crude method which are conventional quantity method for saponin. The pericarp of soapnut trees were collected monthly (from July to October, 2009) from the mother trees located in Zhishan Yen, Taipei city (Tp), Bali,Taipei county (BL) Nantou 151 County road at 1 Km (Nt 1k) and 3 Km (Nt 3k), Danei (DTn) and Zouchen, Tainan (ZTn1~3), Hualien (HL north, east and Tai-Tun), Dong-he (Tt1~3) and Da-Wu (DTt), Taitung and Kaohsiung (Ks) in Taiwan. According to the results, there is a rising trend for every mother trees which were observed. Except for the mother trees in HL (east), the sapogenins content in soapnut tree pericarp decreased slightly from 169.34 to 168.71 mg/g in September to October. In addition, it had the maximum sapogenins content in soapnut tree pericarp in these fifteen mother trees. Then the second and third place in sixteen mother trees is the mother tree in DTn and ZTn2, repectively. The least one is the mother tree in HL (Tai-Tun), its sapogenins content in soapnut tree pericarp is 52.55 mg/g. To realize which parameters affect the difference in maximum sapogenin content in soapnut tree prericarp and their growth rate, we used the three coefficients form sigmoid, slope (single coefficient) from linear function and the values of maximum sapogenin content in soapnut tree prericarp as independent variables, soil properties and environmental parameters as dependent variables. Soil properties include water content in soil, soil pH value, CEC, EC, organic matter, total nitrogen, available phosphorus and testing soil for K, Ca and Mg will be measured. And environmental parameters include mean slope in each quadrat, DTM, mean annual temperature, average temperature from July to October, average precipitation from July to October, total precipitation from July to October, annual total precipitation, forestry area and forestry densty. All of these parameters were conducted to Pearson’s correlation and linear regression. As the results indicate, there are no directly relation between maximum sapogenin content in soapnut tree prericarp, the three coefficients form sigmoid, slope from linear function and soil properties, environmental parameters. In that case, the individual differences have more influence on soapnut tree than soil and environmental parameters.