title: Identification of metabolites in Withania sominfera fruits by liquid chromatography and high-resolution mass spectrometry.
abstract: BACKGROUND
  Withania somnifera is a rich source of biologically active secondary metabolites. Our earlier investigations on the fruits of this plant have yielded novel compounds, withanamides, with potent antioxidant activity and protective effect on β-amyloid-induced cytotoxicity in vitro. However, several minor compounds present in the fruits have not been characterized previously which may contribute to the observed biological activities.
  
  
  METHODS
  Liquid chromatography (LC) coupled with high-resolution mass spectrometry (HRMS) with data-dependent and targeted MS/MS experiments were conducted to elucidate the structure of observed metabolites.
  
  
  RESULTS
  A total of 62 metabolites identified included 32 withanamides, 22 withanolides, 3 steroidal saponins, 2 lignanamides, feruloyl tyramine, methoxy feruloyl tyramine and a diglucoside of hydroxyl palmitic acid. The structures of these compounds were proposed based on accurate masses of the molecular and fragment ions. Several of these new compounds identified from the profile were derived from withanamides with variations in aliphatic and/or glycosyl moieties. In addition, six new withanolides, a new hydroxy fatty acid diglucoside and several known compounds in the extract were identified.
  
  
  CONCLUSIONS
  The current study revealed the presence of several new and known compounds in Withania somnifera fruits. High-resolution MS and MS/MS experiments provide an extremely effective approach to derive the structures of plant secondary metabolites including isomeric compounds.
authors.affiliation: Department of Horticulture, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Jayaprakasam
authors.initials: J
authors.lastname: Bolleddula
authors.forename: William
authors.initials: W
authors.lastname: Fitch
authors.forename: Shaiju K
authors.initials: SK
authors.lastname: Vareed
authors.forename: Muraleedharan G
authors.initials: MG
authors.lastname: Nair
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D004187:Disaccharides / Q000032:analysis; D005638:Fruit / Q000737:chemistry* / Q000378:metabolism; D007211:Indoles / Q000032:analysis; D007783:Lactones / Q000032:analysis; D010936:Plant Extracts / Q000737:chemistry* / Q000378:metabolism; D012503:Saponins / Q000032:analysis; D053719:Tandem Mass Spectrometry / Q000379:methods*; D032341:Withania / Q000737:chemistry* / Q000378:metabolism; D054358:Withanolides / Q000032:analysis
chemical_list: D004187:Disaccharides; D007211:Indoles; D007783:Lactones; D010936:Plant Extracts; D012503:Saponins; D054358:Withanolides