Rapid Identification of Metabolites Using Stabilized hCYP2D6 and Production of Dextrorphan from Dextromethorphan Using Stabilized hCYP2D6

Drug leads and drugs in development must be completely characterized with respect to metabolites produced, preferably with human liver enzymes. Any metabolite > 10% of the drug, must be subject to “Metabolite in Safety Test” (MIST). Key metabolites are also needed as reference compounds. Prep-scale synthesis of metabolites in 2 – 10+ mg is mostly accomplished by use of microsomes from various sources as well as cloned human CYPs in E. coli. This is cumbersome, difficult, low yielding, and time-consuming, expensive. Use of microsomes results in multiple metabolites, including conjugated metabolites. We have undertaken a game-changing approach for prep-scale synthesis of metabolites via highly stabilized dry powder (SDP) of hCYPs. As an example, (i) miniaturization of dextromethorphan (DOM) to dextrorphan (DOH) conversion and rapid identification of DOH and (ii) scale up of DOH production has been demonstrated with SDP-CYP2D6. No external NADPH is required for this reaction. The reaction is conducted in the simplest form, i.e., mixing the drug solution with SDP-CYP2D6. The reaction is scalable to hundreds of mL for metabolite production in 1 – 2 days.