Abstract: The PDA medium containing different concentrations of NaCl was used to isolate the salt-resistant endophytic fungi from wild Glycyrriza uralensis.The extracts were analyzed by TLC and HPLC-UV methods to screen the licorice flavonoids-producing fungi.Totally 108 fungi were obtained and 31 strains were proved to possibly produce licorice flavonoids by TLC.Analyzed by a HPLC-UV method,7 strains of fungi were manifested to produce liquiritin and 3 strains produced isoliquiritin.3 strains produced glycyrrhizin and 3 strains were observed to produce licochalcone A.Finally,the strain named 8-2-G-3 was found to produce echinatin.The DPPH free radical scavening assay results showed that some flavonoids-producing strains,such as liquiritin,isoliquiritin,licochalcone A,and echinatin,had strong antioxidant activities.The strain 8-5-Y-2,which produced liquiritin and isoliquiritin,had a strong activity euqal to total licorice flavonoids while stronger than licochalcone A.Salt-resistant culture was beneficial to obtain the licorice flavonoids-producing salt-resistant fungi which had strong DPPH free radical scavening activity.

Key words: Glycyrrhiza uralensis, salt-resistant endophytic fungi, licorice flavonoids, HPLC-UV, DPPH free radical scavening