Differences in CYP3A4 catalyzed bioactivation of 5-aminooxindole and 5-aminobenzsultam scaffolds in proline-rich tyrosine kinase 2 (PYK2) inhibitors: retrospective analysis by CYP3A4 molecular docking, quantum chemical calculations and glutathione adduct detection using linear ion trap/orbitrap mass spectrometry.
Previous studies have demonstrated the CYP3A4 mediated oxidation of the 5-aminooxindole motif, present in the trifluoromethylpyrimidine class of PYK-2 inhibitors, to a reactive bis-imine species, which can be trapped with glutathione (GSH) in human liver microsomal incubations. The corresponding 5-aminobenzsultam derivatives, which should possess a similar oxidative liability, do not form GSH conjugates in microsomal incubations. In the current study, we conducted a retrospective analysis on representative 5-aminooxindole and 5-aminobenzsultam PYK-2 inhibitors utilizing CYP3A4 molecular docking and quantum chemical calculations to rationalize the bioactivation differences. Our analysis revealed key differences in (a) active site binding and (b) two-electron oxidation rates, which correlate with GSH adduct formation with the two moieties. The value of linear ion/orbitrap mass spectrometry to detect GSH conjugates with greater sensitivity, compared with conventional triple quadrupole mass spectrometry approaches, was also demonstrated in the course of these studies.
Pfizer Global Research and Development, Eastern Point Road, Groton, CT 06340, USA.
Hao
H
Sun
Raman
R
Sharma
Jonathan
J
Bauman
Daniel P
DP
Walker
Gary E
GE
Aspnes
Michael P
MP
Zawistoski
Amit S
AS
Kalgutkar
D000588:Amines / Q000494:pharmacology; D001555:Benzene Derivatives / Q000494:pharmacology*; D002384:Catalysis; D003198:Computer Simulation; D051544:Cytochrome P-450 CYP3A / Q000378:metabolism*; D051418:Focal Adhesion Kinase 2 / Q000037:antagonists & inhibitors*; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D013058:Mass Spectrometry; D008861:Microsomes; D008958:Models, Molecular; D010084:Oxidation-Reduction; D000078183:Oxindoles; D011485:Protein Binding; D047428:Protein Kinase Inhibitors
D000588:Amines; D001555:Benzene Derivatives; D007211:Indoles; D000078183:Oxindoles; D047428:Protein Kinase Inhibitors; C022960:2-oxindole; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human; D051418:Focal Adhesion Kinase 2; D005978:Glutathione