Antimicrobial activity of Inga fendleriana extracts and isolated flavonoids.

The EtOAc and n-BuOH extracts of Inga fendleriana inhibited Gram-positive, but not Gram-negative bacteria; a narrow spectrum of activity against Staphylococcus epidermidis was detected. The MIC values of the extracts ranged from 125 to 850 microg/mL. Quercetin 3-methylether, myricetin 3-O-rhamnoside and tricetin showed antibacterial activity against the same bacterial strains with MICs in the range from 31 to 250 microg/mL. In time-kill kinetic studies, the flavonoids showed bactericidal effects at the concentrations corresponding to four times the MICs.