title: [Optimization of ionic liquid based microwave assisted extraction of five anthraquinones from Polygonum cuspidatum by response surface method].
abstract: OBJECTIVE
  Ionic liquid based microwave-assisted extraction (ILMAE) was developed for the effective extraction of five anthraquinones namely aloeemodin, rhein, emodin, chrysophanol and physcion from Polygonum cuspidatum.
  
  
  METHODS
  Experimental factors and levels were firstly selected by one-factor test. According to the central composite experimental design principle, the response surface methodology with three factors and five levels was adopted for comprehensive assessment by total extraction yield of five anthraquinones as a target.
  
  
  RESULTS
  The optimized parameters of MAE were: 0.6 mol/L [C8 MIM] Br, solvent to solid ratio of 40:1, power of 200 W, temperature of 31 degrees C and extraction time of 8 min. Under the optimal conditions, this approach gained total extraction yield of five anthraquinones 11.69 mg/g, while the predicted total extraction yield was 11.74 mg/g.
  
  
  CONCLUSIONS
  The research indicates ILMAE is an efficient, rapid, environment friendly and simple sample preparation technique to five anthraquinones from Polygonum cuspidatum.
authors.forename: Sai-Fei
authors.initials: SF
authors.lastname: Yang
authors.forename: Yin-Shi
authors.initials: YS
authors.lastname: Sun
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Wang
mesh_terms: D000880:Anthraquinones / Q000737:chemistry / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification*; D004642:Emodin / Q000031:analogs & derivatives / Q000302:isolation & purification; D045468:Fallopia japonica / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry; D008872:Microwaves; D018517:Plant Roots / Q000737:chemistry; D027343:Rhizome / Q000737:chemistry; D013678:Technology, Pharmaceutical; D013696:Temperature
chemical_list: D000880:Anthraquinones; D004365:Drugs, Chinese Herbal; D052578:Ionic Liquids; C518327:aloe emodin; C008905:physcione; D004642:Emodin; C020491:rhein