title: [Ultrasonic extraction for flavonoids from Perilla frutescens by response surface method].
abstract: OBJECTIVE
  To investigate the extraction process of Perilla frutescens flavonoids.
  
  
  METHODS
  Response surface method (RSM) was applied to a fractional design. The Perillafrutescens flavonoids were extracted by ultrasonic method. The influence factors of concentration of alcohol, ratio of liquid to solid, extraction times were evaluated.
  
  
  RESULTS
  The optimum extraction conditions were confirmed as follows: 60% alcohol extracted 4 times, 18 minutes every time and ratio of liquid to solid was 15:1. The extraction rate of flavonoids under this condition was 24. 65 mg/g.
  
  
  CONCLUSIONS
  Applying ultrasonic method to extract Perilla frutescens flavonoids is feasible.
authors.affiliation: Department of Pharmacy, Zhejiang University of Traditional Chinese Medicine, Hangzhou 310053, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Chen-huan
authors.initials: CH
authors.lastname: Yu
authors.forename: Jie
authors.initials: J
authors.lastname: Shen
authors.forename: Qiao-feng
authors.initials: QF
authors.lastname: Wu
mesh_terms: D000704:Analysis of Variance; D005419:Flavonoids / Q000032:analysis / Q000302:isolation & purification*; D006801:Humans; D019686:Lamiaceae / Q000737:chemistry*; D035261:Plant Components, Aerial / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D011208:Powders; D013678:Technology, Pharmaceutical / Q000379:methods*; D013696:Temperature; D013997:Time Factors; D014465:Ultrasonics
chemical_list: D005419:Flavonoids; D011208:Powders