PT  - JOURNAL ARTICLE
AU  - David Q. Liu
AU  - Byron H. Arison
AU  - Ralph A. Stearns
AU  - Dooseop Kim
AU  - Stella H. Vincent
TI  - Characterization of Two Cyclic Metabolites of Sitagliptin
AID  - 10.1124/dmd.106.013128
DP  - 2007 Apr 01
TA  - Drug Metabolism and Disposition
PG  - 521--524
VI  - 35
IP  - 4
4099  - http://dmd.aspetjournals.org/content/35/4/521.short
4100  - http://dmd.aspetjournals.org/content/35/4/521.full
SO  - Drug Metab Dispos2007 Apr 01; 35
AB  - Two novel metabolites of the dipeptidyl peptidase inhibitor sitagliptin (MK-0431, (2R)-4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)-butan-2-amine), were identified after purification from dog urine. The metabolites (referred to as M2 and M5) were characterized by hydrogen/deuterium exchange tandem mass spectrometry and NMR spectroscopy nuclear Overhauser effect experiments as the cis and trans stereoisomers formed by cyclization of the primary amino group with the alpha carbon of the piperazine ring, following oxidative desaturation. The American Society for Pharmacology and Experimental Therapeutics