title: Determination of Oleanolic and Ursolic Acids in Hedyotis diffusa Using Hyphenated Ultrasound-Assisted Supercritical Carbon Dioxide Extraction and Chromatography.
abstract: Oleanolic acid (OA) and ursolic acid (UA) were extracted from Hedyotis diffusa using a hyphenated procedure of ultrasound-assisted and supercritical carbon dioxide (HSC-CO2) extraction at different temperatures, pressures, cosolvent percentages, and SC-CO2 flow rates. The results indicated that these parameters significantly affected the extraction yield. The maximal yields of OA (0.917 mg/g of dry plant) and UA (3.540 mg/g of dry plant) were obtained at a dynamic extraction time of 110 min, a static extraction time of 15 min, 28.2 MPa, and 56°C with a 12.5% (v/v) cosolvent (ethanol/water = 82/18, v/v) and SC-CO2 flowing at 2.3 mL/min (STP). The extracted yields were then analyzed by high performance liquid chromatography (HPLC) to quantify the OA and UA. The present findings revealed that H. diffusa is a potential source of OA and UA. In addition, using the hyphenated procedure for extraction is a promising and alternative process for recovering OA and UA from H. diffusa at high concentrations.
authors.affiliation: Department of Environmental Engineering & Science, Chia Nan University of Pharmacy and Science, Tainan 71710, Taiwan.
authors.forename: Ming-Chi
authors.identifier: 0000-0003-4202-1152
authors.initials: MC
authors.lastname: Wei
authors.affiliation: Department and Graduate Institute of Pharmacology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
authors.forename: Yu-Chiao
authors.identifier: 0000-0001-5769-1795
authors.initials: YC
authors.lastname: Yang
authors.affiliation: Department and Graduate Institute of Pharmacology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
authors.forename: Show-Jen
authors.initials: SJ
authors.lastname: Hong