FIG 6.

Mefloquine derivatives disrupt vacuolar morphology. Exponential-phase cultures of S. cerevisiae reference strain BY4741 were exposed to DMSO or the indicated drug concentrations in YPD at 30°C for 2 h. Concurrently, a culture of S. cerevisiae with a vps1Δ mutation (BY4741 background) was also grown in YPD at 30°C for 2 h without drug or DMSO. All cells were harvested and stained with FM4-64 to visualize the vacuole and photographed. The vacuolar morphology of the treated cultures was similar to the pattern reported for the vps1Δ strain. Propidium iodide staining of the same cultures showed that >95% of cells were viable at the time of processing.