Arslan Ali

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.► First report of CID–MS/MS analysis of 23 pregnane type steroidal alkaloids. ► Identification of key fragments and proposal of logical fragmentation pathways. ► Rapid detection scheme for steroidal alkaloids in complex mixtures using LC–MS/MS. ► Successful validation of LC–MS/MS screening method on Sarcococca coriacea extract. ► Detection of 23 steroidal alkaloids in S. coriacea extract.