We can perform isolation of a targeted metabolite from various in vitro and in vivo matrices followed by unambiguous structural elucidation using NMR. If isolation of metabolites is not feasible from biological matrices, we offer a complimentary approach – biomimetic oxidation.
Comparing the nature and abundances of drug metabolites generated in human and animal species (metabolite profiling) is key to deciding which species to use in preclinical toxicology studies of new chemical entities. The metabolism of the drug candidates is studied in vitro using microsomes, S9 fractions or hepatocytes.
Required by regulatory agencies
Helps select the most appropriate nonclinical tox species based on exposure to all major human metabolites
Predicts unique or disproportionate human metabolites
Identifies metabolic “soft spots”
Certain structural features may predict toxicity of metabolites
Absorption Systems Approach to Metabolite Identification
Our approach is to analyze samples using liquid chromatography (LC) coupled with high resolution accurate mass spectrometry (HRAMS) data processing using MetWorks software can detect expected metabolites based on HRAMS during screening for metabolic stability, during which a list of m/z of molecular ions of the expected metabolites is generated automatically using mass shifts corresponding to common Phase I and Phase II biotransformations. This approach expands the usefulness of metabolic stability studies so that they generate initial metabolite profiling information in addition to determining the intrinsic clearance of the parent compound. Comprehensive metabolite profiling can be performed via a search for unique peaks present in incubation samples but not in the solvent control sample. The more detailed tentative structure assignment of the detected metabolites is achieved via interpretation of MSn spectra of the parent drug and any detected metabolites, and typically involves additional sample re-analysis using targeted LC-HRAMS-MSn methods. Finally, unambiguous structure elucidation of metabolites, based on NMR data, is available. For this purpose, pure metabolites in the required quantities can be isolated from scaled-up biological incubation samples or synthesized using alternative approaches based on biomimetic oxidation.