Energy-coupling factor (ECF) transporters are bacterial proteins involved in the uptake of vitamins. They are potential antibacterial targets to combat pathogens that depend on vitamin uptake. In this ERC-funded project, we performed virtual screening, design, synthesis and structure–activity relationships (SARs) of chemical compounds active against the ECF transporters. We profiled the compounds for their pharmaceutical properties, and found that the best compound has a minimum inhibitory concentration (MIC) value of 2 µg/mL against Streptococcus pneumoniae, which opens up the possibility for further development as antibiotic.