title: Optimization of quercitrin and total flavonoids extraction from Herba Polygoni Capitati by response surface methodology.
abstract: OBJECTIVE
  To optimize the conditions for extraction of quercitrin and total flavonoids (TF) from Herba Polygoni Capitati (Touhualiao in Chinese) by using response surface methodology (RSM).
  
  
  METHODS
  A central composite design (CCD) was adopted to investigate the effects of three independent variables including solvent composition (%), solvent-material ratio (ml/g) and extraction time (min) on the responses, quercitrin and TF yields.
  
  
  RESULTS
  THE OPTIMIZED CONDITIONS OF THE EXTRACTION ARE AS FOLLOWS: Ethanol concentration, 65.63%; solvent-material ratio, 10.55:1 (ml/g); extraction time, 54.33 min. The established mathematical model described the factors of experimental parameters well and provided a statistically accurate prediction of the optimum yields of quercitrin and TF.
  
  
  CONCLUSIONS
  The experimental values agreed with those predicted by the established mathematical model, thus indicating the suitability of the model employed and the success of RSM in optimizing the extraction conditions.
authors.affiliation: The Research Center for Quality Control of Nature Medicine, Guizhou Nomal University, Guiyang, Guizhou, P.R. China ; Key Laboratory for Information System of Mountainous Area and Protection of Ecological Environment of Guizhou province, Guizhou Nomal University, Guiyang, Guizhou, P.R. China.
authors.forename: Fengwei
authors.initials: F
authors.lastname: Ma
authors.affiliation: The Research Center for Quality Control of Nature Medicine, Guizhou Nomal University, Guiyang, Guizhou, P.R. China ; Key Laboratory for Information System of Mountainous Area and Protection of Ecological Environment of Guizhou province, Guizhou Nomal University, Guiyang, Guizhou, P.R. China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: The Research Center for Quality Control of Nature Medicine, Guizhou Nomal University, Guiyang, Guizhou, P.R. China ; Key Laboratory for Information System of Mountainous Area and Protection of Ecological Environment of Guizhou province, Guizhou Nomal University, Guiyang, Guizhou, P.R. China.
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Gong
authors.affiliation: Guizhou Warmen Pharmaceutical Co., Ltd., Guiyang, Guizhou, P.R. China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Xie
authors.affiliation: The Research Center for Quality Control of Nature Medicine, Guizhou Nomal University, Guiyang, Guizhou, P.R. China ; Key Laboratory for Information System of Mountainous Area and Protection of Ecological Environment of Guizhou province, Guizhou Nomal University, Guiyang, Guizhou, P.R. China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
keywords: Central composite design; Extraction; Herba Polygoni Capitati; Optimization; Response surface methodology