Regioselective O-demethylation of the flavones tangeretin (1) and 3-hydroxytangeretin (6) into their 4'-O-demethylated metabolites was performed by using an Aspergillus niger strain. This method serves as a straightforward alternative to multistep synthesis or semisynthesis. The microbial approach is complementary to the chemical procedure, which furnishes a 5-O- demethylated product. P450 inhibitors prevented the biotransformation of tangeretin (1). ...
![4H-1-Benzopyran-4-one,2-[4-(acetyloxy)phenyl]-5,6,7,8-tetramethoxy结构式](https://image.chemsrc.com/caspic/488/6959-55-3.png)
