Biological activities of flavonoids from pathogenic-infected Astragalus adsurgens

The present study was aimed at the identification of biological components from pathogenic-infected Astragalus adsurgens with an activity-guided purification process. Fifteen flavonoids were obtained from the most active ethyl acetate fraction and identified as astradsurnin (1), a new chalcone derivative, together with fourteen known flavonoids (2–15). These compounds were tested for antibacterial activities against five bacteria and cytotoxic activities against two selected cancer cells. Within the series of flavonoids tested, compounds 4 and 15 were the most active against Escherichia coli, Bacillus cereus, Staphylococcus aureus, Erwinia carotovora and Bacillus subtilis with MICs ranging from 7.8 to 31.3 μg/ml. Moreover, compounds 4 and 5 exhibited moderate activity against HL-60 and SMMC-7721 cells with IC50 values between 5 and 10 μg/ml. To our knowledge, this is the first time that it has been reported on the biological and chemical study of A. adsurgens infected by Embellisia astragali.