Biosynthesis of Drug Metabolites and Quantitation Using NMR Spectroscopy for use in Pharmacological and Drug Metabolism Studies.
Biosynthesis of Drug Metabolites and Quantitation Using NMR Spectroscopy for use in Pharmacological and Drug Metabolism Studies.
Drug Metab Dispos. 2014 Jul 22;
Authors: Walker GS, Bauman JN, Ryder T, Smith EB, Spracklin DK, Obach RS
Abstract
The contribution of drug metabolites to the pharmacological and toxicological activity of a drug can be important; however, for a variety of reasons metabolites can frequently be difficult to synthesize. To meet the need of having samples of drug metabolites for further study, we have developed biosynthetic methods coupled with quantitative NMR spectroscopy (qNMR) to generate solutions of metabolites of known structure and concentration. These quantitative samples can be used in a variety of ways when synthetic sample is unavailable, including pharmacological assays, standards for in vitro work to help establish clearance pathways and/or as analytical standards for bioanalytical work to ascertain exposure, among others. In this manuscript five examples of metabolite biosynthesis and qNMR are illustrated. The types of metabolites include one glucuronide and four oxidative products. Concentrations of the isolated metabolite stock solutions ranged from 0.048 to 8.3 mM, with volumes from approximately 0.04 to 0.150 mL in hexadeutarated dimethylsulfoxide (DMSO-d6). These specific quantified isolates were used as standards in the drug discovery setting as substrates in pharmacology assays, for bioanalytical assays to establish exposure and in variety of routine ADME assays like protein binding and determining blood to plasma ratios. The methods used to generate these materials are described in detail with the objective that these methods can be generally used for metabolite biosynthesis and isolation.
PMID: 25053618 [PubMed - as supplied by publisher]
More...