Biotransformation of Glycyrrhetinic Acid by Cunninghamella blakesleeana

AimTo study the hydroxylation in glycyrrhetinic acid (GA) by biocatalysis, and evaluate the antibacterial activities of the derivatives.MethodsThe hydroxylation was performed via incubating GA with a fungus, Cunninghamella blakesleeana (C. blakesleeana) AS 3.970 at 30 °C for 5 days.ResultsGA was converted into two major derivatives and four minor derivatives. The two major derivatives were isolated and elucidated as 3-oxo-7β-hydroxy-glycyrrhetinic acid (GA-1) and 7β-hydroxy-glycyrrhetinic acid (GA-2) based on their spectral data, and other derivatives (GA-3–GA-6) were identified by HR-ESI-MS. The antibacterial activities of substrate and two major derivatives were evaluated on four bacteria strains and one yeast strain.ConclusionCunninghamella blakesleeana AS 3.970 has the capability of hydroxylation for GA. The two major derivatives and GA were found to have considerable activities against drug-resistant Enterococcus faecalis.