title: Optimisation of ultrasound-assisted extraction of puerarin and total isoflavones from Puerariae Lobatae Radix (Pueraria lobata (Wild.) Ohwi) with response surface methodology.
abstract: BACKGROUND
  Isoflavones, particularly puerarin, are a group of important components from Puerariae Lobatae Radix (PLR) which show diverse pharmacological activities, therefore giving rise to the development of various extraction methods. Ultrasound-assisted extraction (UAE) has been explored for isoflavone extraction from PLR as it provides higher extraction efficiency compared with traditional methods.
  
  
  OBJECTIVE
  To optimise the UAE conditions for puerarin and total isoflavone extraction from PLR using response surface methodology (RSM).
  
  
  METHODS
  Samples were prepared by use of ultrasound-assisted extraction, and then subjected to HPLC analysis. Box-Behnken Design (BBD), a widely used form of RSM, was used for the optimisation of the UAE process.
  
  
  RESULTS
  The effects of ethanol concentration, extraction time and the solvent-to-material ratio on the yields of puerarin and total isoflavones were investigated. The Box-Behnken experimental results demonstrate that optimal extraction was obtained with an ethanol concentration of 71.35%, an extraction time of 49.08 min and a solvent-to-material ratio of 21.72 for puerarin, and an ethanol concentration of 80.00%, an extraction time of 55.00 min and a solvent-to-material ratio of 12.81 for total isoflavones. The yields of puerarin and total isoflavones were 41 ± 0.63 mg/g and 128 ± 0.82 mg/g, respectively, under the optimised extraction conditions, which are in agreement with the values predicted by the RSM.
  
  
  CONCLUSIONS
  The RSM allows for optimising the extraction parameters such that maximum extraction of puerarin and total isoflavones was achieved experimentally.
authors.affiliation: School of Pharmacy, Xinxiang Medical University, East of Jinsui Road, 453003 XinXiang, China.
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Wu
authors.forename: Xinsheng
authors.initials: X
authors.lastname: Wang
authors.forename: Enguo
authors.initials: E
authors.lastname: Fan
mesh_terms: D005591:Chemical Fractionation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods / Q000592:standards*; D004365:Drugs, Chinese Herbal / Q000737:chemistry; D007529:Isoflavones / Q000737:chemistry / Q000302:isolation & purification*; D018517:Plant Roots / Q000737:chemistry; D029908:Pueraria / Q000737:chemistry; D012044:Regression Analysis; D012997:Solvents / Q000737:chemistry; D013997:Time Factors; D014465:Ultrasonics
chemical_list: D004365:Drugs, Chinese Herbal; D007529:Isoflavones; D012997:Solvents; C033607:puerarin