title: Quantitation of α-galactosides in Rehmannia glutinosa by hydrophilic interaction chromatography-evaporative light scattering detector.
abstract: BACKGROUND
  The use of raffinose family oligosaccharides (RFOs) to control several diseases and stimulate immune systems has been studied. Rehmannia glutinosa is reported to contain RFOs; however, there are no reports on their content level in R. glutinosa. Furthermore, it is difficult to analyse RFOs using common reverse-phase chromatographic techniques due to their high polarity.
  
  
  OBJECTIVE
  To develop a rapid and reliable chromatographic method for the simultaneous quantitation of multiple RFOs in R. glutinosa.
  
  
  METHODS
  Chromatographic separation was performed by using hydrophilic interaction liquid chromatography coupled with an evaporative light scattering detector. For efficient ultrasound-assisted extraction of oligosaccharides, a central composite design was used.
  
  
  RESULTS
  Response surface analysis estimated the highest-obtained yields of raffinose, stachyose and verbascose to be 58.31, 408.75 and 26.59 mg, respectively, from 1 g of R. glutinosa, while under optimal conditions, experimental yields per gram were 56.79, 391.42 and 27.69 mg, respectively.
  
  
  CONCLUSIONS
  A rapid and reliable chromatographic method to simultaneously quantitate multiple RFOs in R. glutinosa was developed. Three RFOs in R. glutinosa were separated within 10 min using isocratic conditions. Quantitative analysis of RFOs showed that R. glutinosa may be a rich source of α-galacto-oligosaccharides, especially stachyose.
authors.affiliation: College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, 151-742, Korea.
authors.forename: Tae Bum
authors.initials: TB
authors.lastname: Kim
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Sang Hyun
authors.initials: SH
authors.lastname: Sung
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation* / Q000379:methods* / Q000706:statistics & numerical data; D005697:Galactosides / Q000032:analysis* / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D008027:Light; D009844:Oligosaccharides / Q000032:analysis; D011887:Raffinose / Q000032:analysis; D032267:Rehmannia / Q000737:chemistry*; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization; D013696:Temperature
chemical_list: D005697:Galactosides; D009844:Oligosaccharides; C005695:stachyose; C570815:verbascose; D011887:Raffinose