title: Profiles of steroidal saponins from the aerial parts of Tribulus pentandrus, T. megistopterus subsp. pterocarpus and T. parvispinus by LC-ESI-MS/MS.
abstract: BACKGROUND
  Tribulus is a well-known pharmaceutical herb that has been used for a long time in the traditional Chinese and Indian systems of medicine for the treatment of various diseases. It has been found that the genus Tribulus is rich in biologically active furostane-, cholestane- and spirostane-type steroidal saponins.
  
  
  OBJECTIVE
  To develop a rapid, sensitive and accurate method based on liquid-phase extraction followed by high-performance liquid chromatography and electrospray ionisation mass spectrometry (HPLC-ESI-MS) to identify different saponins in three species of the genus Tribulus, and to quantify the compounds that are already known.
  
  
  METHODS
  After extraction from the species studied, the extracts were subjected to HPLC analyses with an XTerra® MS C(18) -column and a binary mobile phase consisting of 0.05% formic acid in water and acetonitrile, and with an ESI-MS detection in the negative ion mode. Data were acquired and processed using the Xcalibur 1.3 software.
  
  
  RESULTS
  The results exhibited that the profiles of native steroidal glycosides of both T. pentandrus and T. megistopterus subsp. pterocarpus were very similar to each other, but that of T. parvispinus was remarkably different. The fragmentation patterns provided evidence that the saponins possess spirostane-, cholestane- and furostane-type aglycones. Quantitative analyses suggested that these species are a rich source of steroidal saponins.
  
  
  CONCLUSIONS
  HPLC-ESI-MS/MS allowed identification of the key compounds without preparative isolation of the components from the crude extract of Tribulus species.
authors.affiliation: Department of Botany, Faculty of Science, South Valley University, Aswan, 81528, Egypt. arafahamed75@yahoo.com
authors.forename: Arafa I
authors.initials: AI
authors.lastname: Hamed
authors.forename: Bogdan
authors.initials: B
authors.lastname: Janda
authors.forename: Usama A
authors.initials: UA
authors.lastname: Mahalel
authors.forename: Anna
authors.initials: A
authors.lastname: Stochmal
authors.forename: Wieslaw
authors.initials: W
authors.lastname: Oleszek
mesh_terms: D002138:Calibration; D002776:Cholestanes / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D059625:Liquid-Liquid Extraction / Q000379:methods; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry; D012503:Saponins / Q000032:analysis* / Q000737:chemistry*; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D032444:Tribulus / Q000737:chemistry*
chemical_list: D002776:Cholestanes; D010936:Plant Extracts; D012503:Saponins