Antimicrobial activity of mannose-derived glycosides

A set of 14 synthetic mannolipid-mimicking O-mannosides, S-mannosides, and mannosylsulfones varying in aglycone length were evaluated for their antimicrobial activity towards yeast Candida albicans as well as Gram-positive and Gram-negative bacteria, Staphylococcus aureus and Escherichia coli, respectively. S. aureus was the most susceptible to dodecyl alpha-d-mannopyranoside showing MIC value of 78 mu M, while dodecyl alpha-d-thiomannopyranoside was superior yeast inhibitor exhibiting twofold lower MIC value. On the other hand, E. coli was resistant to both dodecyl glycosides. Mannosides exposure on RAW 264.7 cell line murine macrophages revealed the tight structure-immunobiological activity pattern. No significant cytotoxic effect and suppression of proliferation as a consequence of cell injury following 24 h exposure with 1-100 mu g/cm(3) mannosides were observed.