Figure 3.
Accumulation of UA (Ursolic acid) (A) or AMPI (ampicillin) (B) in the presence of ampicillin (A) or UA (B) in S. aureus ATCC 33591. In the co-incubation protocol, both compounds were co-incubated for 30 min (T30 AMPI + UA). For the pre-incubation protocol, UA was incubated for 30 min before the addition of ampicillin for 30 min more (T30 UA + T30 AMPI) or the opposite (ampicillin was incubated for 30 min before the addition of UA for 30 min more (T30 AMPI + T30 AMPI). The accumulation was expressed in ng ursolic acid/109 bacteria or µg ampicillin/109 bacteria. The data represent the mean ± SEM of three independent experiments.