Submit Manuscript  

Article Details

Formation of A Novel Purine Metabolite through CYP3A4 Bioactivation and Glutathione Conjugation

[ Vol. 10 , Issue. 2 ]


Julius L. Apuy, Cathie Xiang, Sarah Franc, Sayee G. Hegde, Robert Hubbard, Jingjing Zhao and Mehran F. Moghaddam   Pages 144 - 150 ( 7 )


Background: The study of novel sites of metabolism is important in understanding new mechanisms of biotransformation of a particular moiety by metabolic enzymes. This information is valuable in designing metabolically-stable compounds with drug-like properties. It may also provide insights into the existence of active and reactive metabolites.

Methods: We utilized small scale incubations to generate adequate amounts of the metabolite of interest. After purification, LC-MS/MS and Proton Nuclear Magnetic Resonance (1H-NMR) were utilized to unequivocally assign the novel site of glutathione conjugation on the purine ring system.

Results: A proposed novel site of glutathione conjugation was investigated on a diaminopurine-containing molecule. It was demonstrated that the formation of the glutathione conjugate at the C-6 position of the purine ring system was due to the bioactivation of the compound to a di-imine intermediate by CYP3A4, followed by the nucleophilic addition of glutathione.

Conclusion: S-glutathionylation at C-6 position of a purine was proven unequivocally. This previously unreported mechanism constitutes a novel biotransformation for purines.


Biotransformation, CYP, drug discovery, glutathione, mass spectrometry, metabolite identification, metabolism, novel, NMR, purine, structural elucidation.


Celgene Corporation, 10300 Campus Point Dr, Suite 100, San Diego, CA 92121, USA.

Graphical Abstract:

Read Full-Text article