Fungal biotransformation of morphine alkaloids

The purpose of the study was to determine the ability of certain fungi to biotransform morphine alkaloids into medicinally relevant intermediates. Fungal strains screened for their ability to affect biotransformation of morphine alkaloids include Cunninghamella echinulata, Helicostylum pirijorme, Pycnoporus sanguinea, Pycnoporus cinnabarina, Curvularia lunata and Sporotrichum sulfurescens. The research demonstrated that Cunninghamella echinulata N-demethylated thebaine, hydrocodone, codeine, oripavine and oxycodone into corresponding nor-compounds in varying yields. The study further focused on the characterization of the enzyme responsible for the biotransformation of thebaine into northebaine by Cunninghamella echinulata. The study clearly showed that incubation of the fungal culture with thebaine over a period of 48 hours was required to activate the biotransformation process. The biotransformation studies with [14C] labeled thebaine showed that Ndemethylation by Cunningham ella echinulata does not involve O-demethylation followed by methyl group transfer as suggested in previous studies.