ANTIBACTERIAL ACTIVITY OF (+ -)6-BENZYL-1-(3-CARBOXYPROPYL) INDANE - A POSSIBLE WAY TO IDENTIFY LEADING NOVEL ANTI-H-PYLORI AGENTS/

Magainin 2, isolated from the skin of the Xenopus laevis, is an antimi crobial peptide which reacts directly with the biological membrane to lyse various bacteria from negative and positive microorganisms. In a previous report, we showed that (+/-)1-(4-aminobutyl)-6-benzylindane ( PM2), which mimicked the conformation of the side-chains of a compleme ntary unit on the amino acid sequence of magainin 2 analogy, expressed the in vitro antibacterial activity not only against Helicobacter, py lori (ATCC43526, ATCC43579), but also against Escherichia coli (ATCC25 922) and Staphylococcus aureus (ATCC25923). In addition, PM2 caused hu man blood red cells (RBCs) to lyse at the minimum inhibitory concentra tion (MIC) value. Based on the antibacterial activities of 9-phenylnon anoic acid (pC9c), we further synthesized (+/-)-6-benzyl-1-(3-carboxyp ropyl) indane (PM2c), which replaced a positive charge of PM2 with a n egative one, and tested the biological activities. PM2c had the abilit y to inhibit the growth of H. pylori strains, but its activity to inhi bit the growth of E. coli and S. aureus was not detected and weak, res pectively. Moreover, PM2c showed non-hemolytic activity against RBCs a t the MIC value. These results indicate the possibility that PM2c may be more useful than PM2 either alone or in combination with well-known therapeutic agents for the treatment of H. pylori infection.