Chemical Composition and Disruption of Quorum Sensing Signaling in Geographically Diverse United States Propolis

Figure 3

The flavonoid pinocembrin, which is present in the second group United States propolis, confers QSI activity. Abbreviations include the following: 3OC12, pure 3-oxo-C12 acyl-homoserine lactone (positive control); Pinocembrin, “European type propolis” fraction containing pinocembrin; EtOH, ethyl alcohol; EtOAc, ethyl acetate.