Combination of electrochemistry and nuclear magnetic resonance spectroscopy for metabolism studies.

During the development of new materials demonstrating biological activity, prediction and identification of reactive intermediates generated in the course of drug metabolism in the human liver is of great importance. We present a rapid and purely instrumental method for the structure elucidation of possible phase I metabolites. With electrochemical (EC) conversion adopting the oxidative function of liver-inherent enzymes and nuclear magnetic resonance (NMR) spectroscopy enabling structure elucidation, comprehensive knowledge on potential metabolites can be gained. Paracetamol (APAP) has been known to induce hepatotoxicity when exceeding therapeutic doses and was therefore selected as the test compound. The reactive metabolite N-acetyl-p-benzoquinone imine has long been proven to be responsible for the toxic side effects of APAP and can easily be generated by EC. EC coupled online to NMR is a straightforward technique for structure elucidation of reactive drug intermediates at an early stage in drug discovery.