title: Drug metabolite identification: stable isotope methods.
abstract: This paper focuses on stable isotope labeling of drugs, in combination with mass spectrometry (MS)-based methods, to facilitate the recognition and identification of metabolites and the employment of stable isotope-labeled derivatization reagents (e.g., bis-trimethylsilylacetamide-d18) in the structure elucidation of metabolites from unlabeled drugs via gas-liquid chromatography-MS techniques. In both cases, it is the so-called isotope peak shift that permits generation of data useful for metabolite identification. Furthermore, judicious labeling of a drug permits characterization of drug-related species (metabolites) by MS-based recognition of isotope cluster signatures. Studies using stable isotope-labeled drugs are exemplified by work on aminopyrine and isopropylantipyrine metabolism; examples of the derivatization peak shift approach include those from studies of timolol and cyproheptadine.
mesh_terms: D000818:Animals; D001711:Biotransformation; D002849:Chromatography, Gas; D007554:Isotopes; D013058:Mass Spectrometry; D004364:Pharmaceutical Preparations / Q000378:metabolism*
chemical_list: D007554:Isotopes; D004364:Pharmaceutical Preparations