Synthesis of metabolites of paracetamol and cocaine via photooxidation on TiO2 catalyzed by UV light

Prediction and synthesis of drug metabolites generated by photodegradation using TiO2/UV system in aqueous solution was performed to monitor illicit drugs and to support legal actions against drug dealers.Metabolism of paracetamol and cocaine applied as exemplary compounds was monitored by liquid chromatography mass spectrometry (LC–MS/MS) and direct analysis by electrospray ionization mass spectrometry (ESI–MS/MS). The experiments proved that simulated metabolic pathways of the drug samples are efficient and lead to the formation of products that are observed using living organisms or hepatocyte microsomal preparations. Routinely, TiO2 nanopowders are used for complete degradation of unwanted waste to protect environment. We applied such system for prediction of potential metabolites of harmful substances, such as cocaine. The results demonstrate that TiO2/UV oxidative system can be an efficient, complementary method to the in vivo approaches to obtain important metabolites for further studies. Investigations using such methodology may be helpful for toxicologists providing a vital knowledge on metabolites derived from e.g. newly introduced cognitive enhancers (designer drugs), and home-made substances prepared from the over-the-counter tablets (legal highs).

► We study two model samples, cocaine and paracetamol.
► We predict Phase I and Phase II of photo-oxidation reactions.
► For the first time TiO2 nanopowders applied for such important predictions.
► Several important metabolites were synthesized using the presented method.
► Incubation of cocaine with liver microsomes were performed to compare results.
► LC–MS/MS is a good tool for separation and identification of studied compounds.