title: Rapid characterization and identification of steroidal alkaloids in Sarcococca coriacea using liquid chromatography coupled with electrospray ionization quadropole time-of-flight mass spectrometry.
abstract: Rapid characterization of 23 pregnane-type steroidal alkaloids was studied using a positive ion electrospray ionization quadropole time-of-flight mass spectrometry (ESI-QqTOF-MS/MS) hybrid instrument. ESI-QqTOF-MS (positive ion mode) showed the presence of the protonated molecules [M+H](+) which through low-energy collision-induced dissociation tandem mass spectrometric (CID-MS/MS) analysis showed the characteristic loss of dimethylamine moiety [M+H-45](+) followed by the sequential lossess of attached substituents. Steroidal alkaloids having tigloyl or senecioyl group at C-3 produced diagnostic fragment ions at m/z 100 and 83. Our study also demonstrates the influence of unsaturation, and number and nature of substitutents on product ion abundance and fragment ions. Moreover, the generalization of the fragmentation pattern was linked with the structural features in steroidal skeleton. This strategy was successfully applied in LC-ESI-QqTOF-MS/MS analysis of Sarcococca coriacea extract to investigate and characterize pregnane-type steroidal alkaloids in complex mixture.
authors.affiliation: HEJ Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan. musharraf1977@yahoo.com
authors.forename: Syed Ghulam
authors.initials: SG
authors.lastname: Musharraf
authors.forename: Madiha
authors.initials: M
authors.lastname: Goher
authors.forename: Arslan
authors.initials: A
authors.lastname: Ali
authors.forename: Achyut
authors.initials: A
authors.lastname: Adhikari
authors.forename: M Iqbal
authors.initials: MI
authors.lastname: Choudhary
authors.lastname: Atta-ur-Rahman
mesh_terms: D000470:Alkaloids / Q000032:analysis* / Q000302:isolation & purification; D031234:Buxaceae / Q000737:chemistry*; D002853:Chromatography, Liquid; D010936:Plant Extracts / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D018517:Plant Roots / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013256:Steroids / Q000032:analysis* / Q000302:isolation & purification; D053719:Tandem Mass Spectrometry
chemical_list: D000470:Alkaloids; D010936:Plant Extracts; D013256:Steroids