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.
Sun
Hao
H
Pfizer Global Research and Development, Eastern Point Road, Groton, CT 06340, USA.
Sharma
Raman
R
Bauman
Jonathan
J
Walker
Daniel P
DP
Aspnes
Gary E
GE
Zawistoski
Michael P
MP
Kalgutkar
Amit S
AS
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