title: [Comparison on extraction of volatile oils from Lithospermum erythrorhizon by different methods].
abstract: OBJECTIVE
  To extract the volatile oils from Lithospermum erythrorhizon via ultrasound-enhanced sub-critical water extraction (USWE) and compare with ultrasound-enhanced solvent extraction (USE) and steam distillation extraction (SD).
  
  
  METHODS
  The extraction yield of the volatile oils, the containing components of extract, the effect of scanvenging activities on free radical DPPH and reducing activities as well as the inhibitory on escherichia coli and staphylococcus aureus were investigated.
  
  
  RESULTS
  The extraction yield of volatile oils by USWE, USE and SD were 2.39%, 1.93% and 0.62%, respectively, the extracts by three methods all contained six major components, but the extracts by SD and USE contained more impurities. The inhibitory effect on escherichia coli and staphylococcus aureus of the extract by SD and its reducing action were the best,but those by USWE were the worst.
  
  
  CONCLUSIONS
  the extraction yield of volatile oils by USWE is the highest, and it contains less impurities based on the worst in reducing power and inhibitory effects.
authors.affiliation: College of Science, South China University of Technology, Guangzhou 510640, China. yangrifu@scut.edu.cn
authors.forename: Ri-fu
authors.initials: RF
authors.lastname: Yang
authors.forename: Ping-ping
authors.initials: PP
authors.lastname: Huang
authors.forename: Tai-qiu
authors.initials: TQ
authors.lastname: Qiu
authors.forename: Xiao-dan
authors.initials: XD
authors.lastname: Fan
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D057168:Distillation / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry; D029684:Lithospermum / Q000737:chemistry*; D009822:Oils, Volatile / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D013227:Steam; D013678:Technology, Pharmaceutical / Q000379:methods*; D014465:Ultrasonics / Q000379:methods; D014867:Water / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D009822:Oils, Volatile; D010936:Plant Extracts; D013227:Steam; D014867:Water