Elucidation of Fragmentation Pathways of Zolmitriptan and Eliglustat by Protonated ion High-Resolution QTOF-MS/MS for Highly Accurate Identification and Structural Characterisation
Nageswara Rao Kokkirigadda, Balaram Bhavani, Srinivas Torati, Rajendra Prasad Thatipamula, Yelamanda RaoKandrakonda, Jeelan Basha Shaik, Damu Amooru GangaiahIntroduction:
Zolmitriptan is a Serotonin 5-HT1D receptor agonist developed for the oral treatment of acute migraine. Eliglustat is an oral substrate-reduction therapy used as firstline treatment for Gaucher disease type 1 (GD1). To date, the analytical work available on these drugs is largely confined to forced degradation studies analysed by liquid chromatography– tandem mass spectrometry (LC–MS/MS). Hence, in the present study, the protonated ions ([M+H]+) of Zolmitriptan and Eliglustat were investigated using UPLC coupled with a highresolution mass analyzer, specifically a Q-TOF analyzer with an Electrospray ionization (ESI) source, using collision-induced dissociation (CID) fragmentation.
Methods:
UPLC H-Class coupled to a Xevo G2-Xs Q-TOF mass spectrometer equipped with an ESI source in the positive ion mode was used for the analysis. Water and acetonitrile as mobile phase in a gradient program mode of elution and C18 column as stationary phase was used for UPLC.
Results:
Reasonable fragmentation paths were suggested for protonated ions of Zolmitriptan and Eliglustat, and the elemental compositions of the resulting ions were accurately described by the experimental results of UPLC QTOF-HRMS/MS analysis. This study calculated mass errors for molecular ions below 5.0 ppm and fragment ions below 15.0 ppm.
Discussion:
The unique fragmentation pathways obtained from the HR QTOF-MS/MS study made it easier to analyse and interpret the stability and potential degradation pathways of the protonated ions of Zolmitriptan and Eliglustat. Emerging approaches such as Electron-Activated Dissociation (EAD) offer enhanced capabilities for differentiating structurally similar or isomeric species and may provide complementary insights beyond conventional collision-induced dissociation. While such techniques were not within the scope of the present investigation, they represent a promising direction for future studies focused specifically on isomer characterization. Nevertheless, the current HRMS/MS-based fragmentation-mapping strategy presented here provides a robust and reliable foundation for the structural elucidation of the investigated molecules.
Conclusion:
The prediction of the most probable mass fragmentation pathways for both Zolmitriptan and Eliglustat and the formation mechanisms of the fragment ions enable a higher degree of certainty in their identification and hence make this method appropriate for quality control of these drugs and future research studies.