Synthesis, surfactant properties and antimicrobial activities of methyl glycopyranoside ethers

A series of amphiphilic methyl glucopyranoside ethers incorporating various alkyl chain lengths has been synthesized from commercially available methyl glucopyranosides following an acetalisation/hydrogenolysis sequence. The amphiphilic properties of ethers and acetal intermediates were evaluated. Both families exhibit excellent surfactant properties with a maximum efficiency obtained for compounds bearing a linear dodecyl chain (CMC = 0.012 mM, γ_sat. = 30 mN m^-1). Antimicrobial activity studies revealed an efficient activity (0.03 < MIC < 0.12 mM) against Gram-positive bacteria such as Listeria monocytogenes, Enterococcus faecalis, Enterococcus faecium and Staphylococcus aureus. More importantly, these compounds were found to be active against multi-resistant strains such as vancomycin-, methicillin- and daptomycin-resistant strains. Finally, it was found that antimicrobial activities are closely related to physicochemical properties and are also influenced by the nature of the carbohydrate moiety.