Synthesis and in vitro selective anti-Helicobacter pylori activity of N-substituted-2-oxo-2H-1-benzopyran-3-carboxamides.

In order to develop new anti-Helicobacter pylori agents, five new and three already known N-substituted-2-oxo-2H-1-benzopyran-3-carboxamides (coumarin-3-carboxamides) were prepared and evaluated for their antibacterial activity. All synthesized compounds showed little or no activity against different species of Gram-positive and Gram-negative bacteria of clinical relevance and against various strains of pathogenic fungi. Among the prepared compounds those with a 4-acyl-phenyl group showed the best activity against H. pylori metronidazole resistant strains in the 0.25-1 microg/ml MIC range, indicating the presence of an acyl function as an important feature for activity.