FIG 5.
Effects of oxygen in ubiquinone radioactive incorporation and atovaquone efficacy. (a) RP-HPLC metabolic profiles of [3H] GGPP-radiolabeled P. falciparum-infected erythrocytes maintained for 48 h under 5% oxygen or in oxygen-free gaseous mixtures. In all experiments, the samples were co-injected with UQ standards. This experiment was performed thrice with similar results. The fractions were collected at 0.75 min. UQ-8, ubiquinone-8; UQ-9, ubiquinone-9; UQH2-9, ubiquinol-9. (b) The IC50 of AV under oxygen-free or classic gaseous conditions (5% O2). Results represent the mean of three identical experiments. Results were analyzed by unpaired t test in comparison to the control (5% O2); ***, P < 0.001.