Microbial transformation of fraxinellone by Aspergillus niger

Microbial transformation of fraxinellone (1) by Aspergillus niger (AS 3.421) has been carried out. Two converted products, dasycarpol (2) and a new compound fraxinigerllone (3) were obtained. Their structures have been identified on the basis of spectroscopic methods. Dasycarpol shows moderate inhibitory activity on lung cancer cell line A549.