ABSTRACT
Objective: To study the microbial transformation of ursolic acid using Penicillium melinii. Methods: Ursolic acid was put into the fluid medium inoculated with fungius (P. melinii AS3.4774) and cultured in the shaker at 28 °C and 140 r/min for 5 d. The crude extract was separated by chromatography. The structures of transformed products were elucidated based on the extentive NMR studies. Results: Ursolic acid was transformed by P. melinii AS3.4774 and three major derivatives were isolated and elucidated. They were 3-carbonyl ursolic acid, ursolic acid-28-O-β-D-glucopyranosyl ester, and ursolic acid-3-O-β-D-glucopyranoside. Conclusion: It is the first time that the three major derivatives could be microbial synthesized from ursolic acid by P. melinii AS3.4774.