title: Application of comprehensive NMR-based analysis strategy in annotation, isolation and structure elucidation of low molecular weight metabolites of Ricinus communis seeds.
abstract: BACKGROUND
  Powder-like extract of Ricinus communis seeds contain a toxic protein, ricin, which has a history of military, criminal and terroristic use. As the detection of ricin in this "terrorist powder" is difficult and time-consuming, related low mass metabolites have been suggested to be useful for screening as biomarkers of ricin.
  
  
  OBJECTIVE
  To apply a comprehensive NMR-based analysis strategy for annotation, isolation and structure elucidation of low molecular weight plant metabolites of Ricinus communis seeds.
  
  
  METHODS
  The seed extract was prepared with a well-known acetone extraction approach. The common metabolites were annotated from seed extract dissolved in acidic solution using (1)H NMR spectroscopy with spectrum library comparison and standard addition, whereas unconfirmed metabolites were identified using multi-step off-line HPLC-DAD-NMR approach.
  
  
  RESULTS
  In addition to the common plant metabolites, two previously unreported compounds, 1,3-digalactoinositol and ricinyl-alanine, were identified with support of MS analyses.
  
  
  CONCLUSIONS
  The applied comprehensive NMR-based analysis strategy provided identification of the prominent low molecular weight metabolites with high confidence.
authors.affiliation: Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, 11158, Belgrade, Serbia.
authors.forename: Ivan
authors.initials: I
authors.lastname: Vučković
authors.affiliation: VERIFIN, Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014, Helsinki, Finland.
authors.forename: Marja-Leena
authors.initials: ML
authors.lastname: Rapinoja
authors.affiliation: VERIFIN, Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014, Helsinki, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Vaismaa
authors.affiliation: VERIFIN, Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014, Helsinki, Finland.
authors.forename: Paula
authors.initials: P
authors.lastname: Vanninen
authors.affiliation: VERIFIN, Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014, Helsinki, Finland.
authors.forename: Harri
authors.initials: H
authors.lastname: Koskela
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives / Q000032:analysis / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005697:Galactosides / Q000032:analysis / Q000737:chemistry; D007294:Inositol / Q000031:analogs & derivatives / Q000032:analysis / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D015394:Molecular Structure; D008970:Molecular Weight; D011728:Pyridones / Q000032:analysis / Q000378:metabolism; D012276:Ricin / Q000378:metabolism; D012278:Ricinus / Q000737:chemistry* / Q000378:metabolism*; D012639:Seeds / Q000737:chemistry* / Q000378:metabolism
chemical_list: D005697:Galactosides; D011728:Pyridones; D007294:Inositol; D012276:Ricin; D000409:Alanine
keywords: HPLC; LC-MS; NMR; Ricinus communis; analysis strategy; low molecular weight metabolites