title: A preparative method for isolation of fucoxanthin from Eisenia bicyclis by centrifugal partition chromatography.
abstract: BACKGROUND
  Eisenia bicyclis (Kjellman) Setchell (Laminariaceae) is a common brown alga that inhabits around the coast of Korea, Japan and China. It contains fucoxanthin, a major carotenoid of brown algae which shows a variety of pharmaceutical functions.
  
  
  OBJECTIVE
  The aim of this investigation was the quantification and preparative isolation of fucoxanthin from fresh E. bicyclis using a new separation scheme, centrifugal partition chromatography (CPC).
  
  
  METHODS
  The fucoxanthin fraction (Fuco fraction) was prepared by solvent partition method from the acetone extract of fresh E. bicyclis. Fuco fraction was used for CPC using a two-phase solvent system of n-hexane-ethyl acetate-ethanol-water (5:5:7:3, v/v/v/v). The flow rate of mobile phase was 2 mL/min with descending mode while rotating at 1000 rpm. The eluate was monitored at 410 nm. The content and structure of fucoxanthin in the CPC fraction were confirmed with HPLC, UV, APCI/MS and NMR spectra.
  
  
  RESULTS
  A preparative CPC yielded 20 mg of fucoxanthin (87% recovery from Fuco fraction) in a two-step separation from 516 mg of Fuco fraction containing 4.59% fucoxanthin. The purity of the isolated fucoxanthin was about 81% in the first CPC step and over 98% in the second CPC step based on the calibration curve. The isolated fucoxanthin was identified as all-trans-fucoxanthin with APCI/MS (parent ion at m/z 641 [M + H - H(2) O](+) ) and (1) H, (13) C and 2-D NMR spectra.
  
  
  CONCLUSIONS
  High-purity fucoxanthin was successfully isolated from fresh E. bicyclis, suggesting further potential applications in the industrial use of this valuable carotenoid.
authors.affiliation: Natural Product Research Center, KIST Gangneung Institute, Gangwon, 210-340 Republic of Korea.
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Kim
authors.forename: Ya Fang
authors.initials: YF
authors.lastname: Shang
authors.forename: Byung-Hun
authors.initials: BH
authors.lastname: Um
mesh_terms: D002498:Centrifugation / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D013058:Mass Spectrometry / Q000379:methods*; D000459:Phaeophyceae / Q000737:chemistry*; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry*; D011312:Pressure; D012997:Solvents; D024341:Xanthophylls / Q000032:analysis / Q000302:isolation & purification*
chemical_list: D010936:Plant Extracts; D012997:Solvents; D024341:Xanthophylls; C025164:fucoxanthin