title: Identification and structural characterization of steroidal glycosides in Hoodia gordonii by ion-trap tandem mass spectrometry and liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry.
abstract: Electrospray ion-trap tandem mass spectrometry (ESI-MS/MS) and high-performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry (LC/ESI-TOFMS) were used to identify and characterize eight C-21 steroidal glycosides in Hoodia gordonii. A generalized fragmentation pathway was proposed by comparing the spectra acquired for eight C-21 steroidal glycosides. The steroidal glycosides in Hoodia gordonii have been classified into two major core groups: hoodigenin A and calogenin. Using the ESI-TOF method, the major core peak ions generated by hoodigenin A glycosides are m/z 313 and 295 and by calogenin glycosides are m/z 479, 461, 299 and 281, respectively. In the MS/MS spectra, fragmentation reactions of the [M+Na](+) ion were recorded to provide structural information about the glycosyl and aglycone moieties. The data illustrates the ability of positive mode ESI for the identification of hoodigenin A and calogenin glycosides, including the nature of the hoodigenin A and calogenin core, the number of sugar residues and the type of saccharide moiety.
authors.affiliation: National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy.
authors.forename: Bharathi
authors.initials: B
authors.lastname: Avula
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Wang
authors.forename: Rahul S
authors.initials: RS
authors.lastname: Pawar
authors.forename: Yatin J
authors.initials: YJ
authors.lastname: Shukla
authors.forename: Troy J
authors.initials: TJ
authors.lastname: Smillie
authors.forename: Ikhlas A
authors.initials: IA
authors.lastname: Khan
mesh_terms: D029062:Apocynaceae / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D006027:Glycosides / Q000032:analysis*; D010936:Plant Extracts / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013256:Steroids / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D006027:Glycosides; D010936:Plant Extracts; D013256:Steroids