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    Please use this identifier to cite or link to this item: http://ir.cnu.edu.tw/handle/310902800/29701

    標題: Ethanol solution-modified supercritical carbon dioxide extraction of triterpenic acids from Hedyotis corymbosa with ultrasound assistance and determination of their solubilities
    作者: Yang, Yu-Chiao
    Wei, Ming-Chi
    貢獻者: 環境工程與科學系
    關鍵字: Hedyotis corymbosa
    Triterpenic acids
    Hyphenated supercritical CO2 extraction
    Density-based model
    日期: 2015-08
    上傳時間: 2016-04-19 19:05:09 (UTC+8)
    出版者: Elsevier Science Bv
    摘要: Oleanolic acid (OA) and ursolic acid (UA) have been considered to be two of the most valuable bioactive compounds in Hedyotis corymbosa and might be responsible for its therapeutic effectiveness. In this study, OA and UA were extracted from this plant with a hyphenated procedure for ultrasound-assisted SC-CO2 (HSC-CO2) extraction at various cosolvent (80% ethanol, v/v) percentages (2.5-15.4%, v/v), extraction times (15-105 min), temperatures (33-68 degrees C) and pressures (11.0-32.0 MPa). Conventional SC-CO2 extraction was also performed with the aim of comparing the utility of these two extraction techniques for the analysis of the discussed compounds in H. corymbosa samples. It was found that HSC-CO2 extraction had higher yield and efficiency than conventional SC-CO2 extraction. The solubilities of OA and UA in SC-CO2 were further determined at various temperatures and pressures. In addition, the solubility data of OA and UA in SC-CO2 showed a good agreement with the values obtained from the Bartle, Chrastil and modified Kumar and Johnston models. Using the results of these correlation analyses, the total heat of solution and the enthalpies of vaporization and solvation for OA and UA were approximately estimated
    關聯: Separation And Purification Technology, v.150, pp.204-214
    Appears in Collections:[環境工程與科學系(所)] 期刊論文

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