Abstract: There is provided a method of preparing a benzylisoquinoline alkaloid (BIA) metabolite comprising: a. culturing a host cell under conditions suitable for protein production, including a pH of between about 7 and about 10 said host cell comprising: b. a first heterologous coding sequence encoding a first enzyme involved in a metabolite pathway that converts (R,S)-norlaudanosoline into the metabolite; c. a second heterologous coding sequence encoding a second enzyme involved in a metabolite pathway that converts (R,S)-norlaudanosoline into the metabolite; d.