Two new compounds from biotransformation of glycyrrhetinic acid.

Glycyrrhetinic acid may undergo biotransformation to obtain derivatives with stronger pharmacological activity and fewer side effects. This study used 19 fungi to biotransform glycyrrhetinic acid and yielded two compounds namely bicyclo(14.15.27)glycyrrhetinic acid (1) and 2-ene-glycyrrhetinic acid (2) from the glycyrrhetinic acid metabolites of two fungi, Botrytis cinerea B05.10 ATCC 11542 and Aspergillus ochraceopetaliformis ATCC 12066. Compound 1 inhibited HMEC-1 cell proliferation in a concentration-dependent manner (IC50=239.1 µ M), but showed no significant cytotoxicity to A549 cells.