A novel set of compounds with antimicrobial properties has been discovered in the fight against Helicobacter pylori, a bacterium that has infected more than 1 billion people worldwide and causes gastrointestinal troubles that can lead to cancer (ACS Chem. Biol., DOI: 10.1021/cb900166q). Treatment with conventional broad-spectrum antibiotics such as amoxicillin and clarithromycin is effective, but H. pylori is becoming resistant to these drugs. By high-throughput screening of a library of 10,000 compounds, Javier Sancho of Spain’s University of Zaragoza and colleagues identified four compounds that inhibit flavodoxin, a protein involved in an essential H. pylori metabolic pathway. Three of the compounds, including the two shown, demonstrate selective bactericidal activity against H. pylori and have no apparent toxic effects in mice. The researchers note that these compounds represent promising leads for narrow-spectrum antibiotics to treat H. pylori infections.