Microbial transformation of ursolic acid by Penicillium adametzi / 中草药

ABSTRACT

Objective: To study the microbial transformation of ursolic acid by Penicillium adametzi. Methods: The biotransformed extract was obtained by co-culture of substrate (ursolic acid) and the transferring fungi in a liquid medium at certain conditions, and then the inocula were dealt in an ultrasonic bath and extracted with n-BuOH. The transformed extract was isolated by chromatography on macroporous resin column, silica gel column, and preparative HPLC. The structures of the isolated compounds were identified by spectral analyses, physical constants, and chemical evidences. Results: A microbial transformed product was isolated and identified as 3β, 21α-dihydroxyl-ursolic acid-28-O-β-D-glucopyranoside and it had the significant inhibitory effects against HepG2 cell with IC50 value of 19.72 μmol. Conclusion: The transformed product, 3β, 21α-dihydroxyl-ursolic acid-28-O-β-D-glucopyranoside, is a new compound with the stronger cytotoxic activity than that of substrate.