ABSTRACT
Within the discipline of drug metabolism, the structural elucidation of metabolites can be highly impactful from early discovery through development. Early in the discovery timeline, the structure of a metabolite may have influence on the selection of chemical lead material for progression to development; in later stage development, structural characterization of metabolites is a requirement for drug registration (Iverson and Smith, 2016; Wang and Urban, 2004; Watt et al., 2003). Since the advent of electrospray, mass spectrometry has dominated as the premier analytical technique for structure elucidation of metabolites. This is primarily due to the sensitivity of modern mass spectrometers, which can provide valuable information on the molecular weight, from which the empirical formula may be inferred (Zhang and Mitra, 2012; Zhu et al., 2011). In addition to the empirical formula, MS/MS techniques can lead to the identification of molecular regions that have been modified in a metabolite. While the information gleaned from mass spectrometry data is essential to structural elucidation, it is often not sufficient for unambiguous determination of a metabolite’s structure. In these cases, NMR spectroscopy is often the analytical method of choice.
