Biotransformation of artemisinin mediated through fungal strains for obtaining derivatives with novel activities

Artemisinin, a sesquiterpene lactone, is the active antimalarial constituent of Artemisia annua. Several fungal strains Saccharomyces cerevisiae, Aspergillus flavus, Aspergillus niger and Picchia pastoris were used to biotransform artemisinin. Among these strains, A. flavus was the only microorganism capable of transforming artemisinin to deoxyartemisinin in higher yields than the previous reports. The structure of deoxyartemisinin was elucidated by spectroscopy. Deoxyartemisinin showed antibacterial activity against Staphylococcus aureus, S. epidermidis and S. mutans at a minimum inhibitory concentration (MIC) of 1 mg/mL compared to artemisinin whose MIC was >2 mg/mL.