title: Optimization of the extraction process for the seven bioactive compounds in Yukmijihwang-tang, an herbal formula, using response surface methodology.
abstract: BACKGROUND
  Yukmijihwang-tang (YJT) contains multiple bioactive compounds. Heat-reflux extraction was employed and optimized for the extraction of the bioactive compounds in YJT.
  
  
  OBJECTIVE
  The determination of optimal conditions with maximum yields of bioactive compounds, gallic acid, 5-hydroxymethylfurfural, morroniside, loganin, paeoniflorin, benzoic acid and paeonol, in YJT.
  
  
  METHODS
  The extraction ratio (ratio of water to herbal formula), extraction time and extraction number were set as individual values and the yields of the seven compounds were the response values that were optimized with a Box-Behnken design.
  
  
  RESULTS
  The optimal conditions obtained from response surface methodology (RSM) were 1:11.99 for the extraction ratio, 94.53 min for the extraction time and 2.21 for the extraction number. Under the optimal conditions, the response value of the experiment closely agreed with the predicted response value.
  
  
  CONCLUSIONS
  The result suggests that RSM is successfully applied for optimizing the extraction of the marker compounds in YJT.
authors.affiliation: Herbal Medicine Formulation Research Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine, Daejeon 305-811, Republic of Korea.
authors.forename: Jung-Hoon
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Herbal Medicine Formulation Research Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine, Daejeon 305-811, Republic of Korea.
authors.forename: Hyeun-Kyoo
authors.initials: HK
authors.lastname: Shin
authors.affiliation: Herbal Medicine Formulation Research Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine, Daejeon 305-811, Republic of Korea.
authors.forename: Chang-Seob
authors.initials: CS
authors.lastname: Seo
keywords: Bioactive compounds; Yukmijihwang-tang; heat-reflux extraction; optimal condition; response surface methodology