title: Biological and surface-active properties of double-chain cationic amino acid-based surfactants.
abstract: Cationic amino acid-based surfactants were synthesized via solid phase peptide synthesis and terminal acylation of their α and ε positions with saturated fatty acids. Five new lipopeptides, N-α-acyl-N-ε-acyl lysine analogues, were obtained. Minimum inhibitory concentration and minimum bactericidal (fungicidal) concentration were determined on reference strains of bacteria and fungi to evaluate the antimicrobial activity of the lipopeptides. Toxicity to eukaryotic cells was examined via determination of the haemolytic activities. The surface-active properties of these compounds were evaluated by measuring the surface tension and formation of micelles as a function of concentration in aqueous solution. The cationic surfactants demonstrated diverse antibacterial activities dependent on the length of the fatty acid chain. Gram-negative bacteria and fungi showed a higher resistance than Gram-positive bacterial strains. It was found that the haemolytic activities were also chain length-dependent values. The surface-active properties showed a linear correlation between the alkyl chain length and the critical micelle concentration.
authors.affiliation: Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Gdańsk, Gen. J. Hallera 107, 80-416, Gdańsk, Poland, greber@gumed.edu.pl.
authors.forename: Katarzyna E
authors.initials: KE
authors.lastname: Greber
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Dawgul
authors.forename: Wojciech
authors.initials: W
authors.lastname: Kamysz
authors.forename: Wiesław
authors.initials: W
authors.lastname: Sawicki
authors.forename: Jerzy
authors.initials: J
authors.lastname: Łukasiak
mesh_terms: D000215:Acylation; D000596:Amino Acids / Q000737:chemistry / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology*; D015195:Drug Design; D005227:Fatty Acids / Q000737:chemistry; D005658:Fungi / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D055666:Lipopeptides / Q000737:chemistry / Q000494:pharmacology; D008823:Micelles; D008826:Microbial Sensitivity Tests; D060327:Solid-Phase Synthesis Techniques; D013501:Surface-Active Agents / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000596:Amino Acids; D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D005227:Fatty Acids; D055666:Lipopeptides; D008823:Micelles; D013501:Surface-Active Agents