Bioanalytical method for evaluating the pharmacokinetics of the GCP-II inhibitor 2-phosphonomethyl pentanedioic acid (2-PMPA).
2-Phosphonomethyl pentanedioic acid (2-PMPA) is a potent and selective inhibitor of glutamate carboxypeptidase-II, an enzyme which catabolizes the abundant neuropeptide N-acetyl-aspartyl-glutamate (NAAG) to N-acetylaspartate (NAA) and glutamate. 2-PMPA demonstrates robust efficacy in numerous animal models of neurological disease, however its pharmacokinetics has not yet been fully described. 2-PMPA is a highly polar compound with multiple negative charges causing significant challenges for analysis in biological matrices. Here we report a derivatization method for the acidic groups that involved protein precipitation with acetonitrile followed by reaction with N-tert-butyldimethysilyl-N-methyltrifluoroacetamide (MTBSTFA). The silylated analyte with transitions (683→551.4) and the internal standard (669→537.2) were monitored by tandem mass spectrometry with electrospray positive ionization mode. The method was subsequently used to evaluate 2-PMPA pharmacokinetics in rats. Intraperitoneal administration of 100mg/kg 2-PMPA resulted in maximum concentration in plasma of 275μg/mL at 0.25h. The half-life, area under the curve, apparent clearance, and volume of distribution were 0.64h, 210μg×h/mL, 7.93mL/min/kg, and 0.44L/kg, respectively. The tissue/plasma ratios in brain, sciatic nerve and dorsal root ganglion were 0.018, 0.120 and 0.142, respectively. In summary, a sensitive analytical method for 2-PMPA is reported that can be employed for similarly charged molecules.
Brain Science Institute, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
Rana
R
Rais
Camilo
C
Rojas
Krystyna
K
Wozniak
Ying
Y
Wu
Ming
M
Zhao
Takashi
T
Tsukamoto
Michelle A
MA
Rudek
Barbara S
BS
Slusher
D000818:Animals; D019540:Area Under Curve; D001921:Brain / Q000187:drug effects; D002138:Calibration; D002623:Chemistry Techniques, Analytical; D002626:Chemistry, Pharmaceutical; D002853:Chromatography, Liquid; D004791:Enzyme Inhibitors / Q000097:blood / Q000493:pharmacokinetics*; D005727:Ganglia, Spinal / Q000187:drug effects; D043425:Glutamate Carboxypeptidase II / Q000037:antagonists & inhibitors*; D007263:Infusions, Parenteral; D008297:Male; D009943:Organophosphorus Compounds / Q000097:blood / Q000493:pharmacokinetics*; D010949:Plasma / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D012584:Sciatic Nerve / Q000187:drug effects; D053719:Tandem Mass Spectrometry; D014018:Tissue Distribution
C402107:2-(phosphonomethyl)pentanedioic acid; D004791:Enzyme Inhibitors; D009943:Organophosphorus Compounds; D043425:Glutamate Carboxypeptidase II
2-PMPA; 2-PMSA; 2-phosphonomethyl pentanedioic acid; 2-phosphonomethyl succinic acid; ANOVA; AUC; AULQ; Brain/plasma ratio; C(max); CE; CXP; DP; DRG; Derivatization; EP; GCP-II; Glutamate carboxypeptidase-II; HQC; LLOQ; LQC; MQC; MTBSTFA; N-acetyl-aspartyl glutamate; N-acetylated-alpha-linked acidic dipeptidase; N-tert-butyldimethysilyl-N-methyl trifluoroacetamide; NAAG; NAALADase; PSMA; Pharmacokinetics; T(max); above upper limits of quantitation; area under the concentration–time curve; collision cell exit potential; collision energy; declustering potential; dorsal root ganglion; entrance potential; glutamate carboxypeptidase-II; high quality control; low quality control; lower limit of quantitation; maximum plasma concentration; medium quality control; one-way analysis of variance; prostate specific membrane antigen; time to C(max)