title: Chemoenzymatic synthesis and antimicrobial and haemolytic activities of amphiphilic bis(phenylacetylarginine) derivatives.
abstract: Novel bis(N(alpha)-phenylacetyl-L-arginine)-alpha,omega-alkanediamide dihydrochloride (bis(PhAcArg)) derivatives with antimicrobial activity were designed and synthesised by a chemoenzymatic strategy. The new structures consist of two N(alpha)-phenylacetyl-L-arginine moieties connected by an alkanediamine spacer chain of 6, 8, 10, 12, and 14 methylene units through amide bonds. The key step in the chemoenzymatic strategy is the double aminolysis of the N(alpha)-phenylacetyl-L-arginine methyl ester by the corresponding alpha,omega-alkanediamine catalyzed by papain in ethanolic media. The compounds synthesised were tested as antimicrobials against 15 bacterial and 8 fungal species. The antimicrobial activity and selectivity depend strongly on the spacer chain length. The bis(PhAcArg) derivative with the spacer chain of 12 methylene groups gave the lowest MIC values against Gram-positive bacteria, whereas that with 14 methylene units was the best against Gram-negative bacteria. Interestingly, these novel compounds showed enhanced antibacterial activity relative to the lead compound, bis(N(alpha)-caproyl-L-arginine)-1,3-propanediamide dihydrochloride (C(3)(CA)(2)), and moderate antifungal activity. Moreover, tests of haemolytic activity toward human erythrocytes revealed that haemolysis increases with spacer chain length. Importantly, the compounds were classified as not irritating to eyes, with the exception of the compound with the spacer chain of 14 methylene groups, which was a slight eye irritant.
authors.affiliation: Institute for Chemical and Environmental Research, CSIC c/Jordi Girona 18-26, Barcelona, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Castillo
authors.forename: M Rosa
authors.initials: MR
authors.lastname: Infante
authors.forename: Angels
authors.initials: A
authors.lastname: Manresa
authors.forename: M Pilar
authors.initials: MP
authors.lastname: Vinardell
authors.forename: Montserrat
authors.initials: M
authors.lastname: Mitjans
authors.forename: Pere
authors.initials: P
authors.lastname: Clapés
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D000935:Antifungal Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D001120:Arginine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D004912:Erythrocytes / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects*; D006801:Humans; D008826:Microbial Sensitivity Tests; D008968:Molecular Conformation; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; C515751:bis(phenylacetylarginine); D001120:Arginine