title: Immunochromatographic assay for the detection of pseudojujubogenin glycosides.
abstract: BACKGROUND
  Bacopa monnieri contains pseudojujubogenin glycosides as pharmacologically active compounds. In order to screen large numbers of plant samples for the presence of pseudojujubogenin glycosides, a rapid and simple assay system is required for application to small quantities of test materials. Immunoassays using monoclonal antibodies could be useful for the determination of small quantities of pseudojujubogenin glycosides in plant extracts.
  
  
  OBJECTIVE
  The objective of this work was to develop a simple method for the detection of pseudojujubogenin glycosides by the immunochromatographic strip test using anti-bacopaside I monoclonal antibody.
  
  
  METHODS
  The qualitative assay was based on a competitive immunoassay in which the detector reagent consisted of a colloidal gold particle coated with the respective anti-bacopaside I MAb. The capture reagent was a bacopaside I-human serum albumin conjugate immobilised onto a test strip membrane.
  
  
  RESULTS
  The sample containing pseudojujubogenin glycosides and the detection reagent were incubated with the immobilised capture reagent. The glycosides in the sample competed in binding to the limited amount of antibodies in the detection reagent with the immobilised bacopaside I-HSA conjugates and, hence, positive samples showed no colour in the capture spot zone. The detection limit for the strip test was 125 ng/mL.
  
  
  CONCLUSIONS
  The assay system was found to be useful as a rapid and simple screening method for the detection of pseudojujubogenin glycosides in plants.
authors.affiliation: Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Natnapa
authors.initials: N
authors.lastname: Imsungnoen
authors.forename: Watoo
authors.initials: W
authors.lastname: Phrompittayarat
authors.forename: Kornkanok
authors.initials: K
authors.lastname: Ingkaninan
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Waraporn
authors.initials: W
authors.lastname: Putalun
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry; D034681:Bacopa / Q000737:chemistry*; D002845:Chromatography; D004797:Enzyme-Linked Immunosorbent Assay; D006027:Glycosides / Q000737:chemistry; D017979:Gold Colloid / Q000737:chemistry; D007120:Immunochemistry; D007202:Indicators and Reagents; D010936:Plant Extracts / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D014315:Triterpenes / Q000737:chemistry* / Q000276:immunology; D031957:Ziziphus / Q000737:chemistry
chemical_list: C508084:3-O-(beta-D-glucopyranosyl-(1-3)-beta-D-glucopyranosyl) pseudojujubogenin; D000911:Antibodies, Monoclonal; D006027:Glycosides; D017979:Gold Colloid; D007202:Indicators and Reagents; D010936:Plant Extracts; D014315:Triterpenes