Biological and surface-active properties of double-chain cationic amino acid-based surfactants
- 448 Downloads
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.
KeywordsLipopeptides Surfactants Antimicrobial activity Critical micelle concentration
Colony forming units
Critical micelle concentration
Minimum bactericidal concentration
Minimum fungicidal concentration
Minimum inhibitory concentration
This research was supported by the Medical University of Gdańsk, Project W-117 and the Ministry of Science and Higher Education, Project NN 305 412438.
Conflict of interest
The authors declare that they have no conflict of interest.
- Brito RO, Marques EF, Silva SG, do Vale ML, Gomes P, Araújo MJ, Rodriguez-Borges JE, Infante MR, Garcia MT, Ribosa I, Vinardell MP, Mitjans M (2009) Physicochemical and toxicological properties of novel amino acid-based amphiphiles and their spontaneously formed cationic vesicles. Colloids Surf B Biointerfaces 72(1):80–87PubMedCrossRefGoogle Scholar
- Chan WC, White PD (2004) Fmoc solid phase peptide synthesis. A practical approach. Oxford University Press, New YorkGoogle Scholar
- CLSI (2009) Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically; approved standard. 8th ednGoogle Scholar
- CLSI (2010) Performance standards for antimicrobial susceptibility testing. 20th informational supplementGoogle Scholar
- Denyer SP, Baird RM (2007) Guide to microbiological control in pharmaceuticals and medical devices. CRC Press, New YorkGoogle Scholar