Antibacterial properties of phenolic triterpenoids against Staphylococcus epidermidis.
Two phenolic triterpenoids, pristimerol (30 µg/mL) and 8- EPI-6-deoxoblepharodol (20 µg/mL), obtained by catalytic reduction of pristimerin, exhibited bacteriostatic action against Staphylococcus epidermidis. This activity was not dependent on the inoculum size and the growth phase although it showed a stronger effect when cells were growing actively. Addition of phenolic triterpenoids to S. epidermidis cultures in the log-phase of growth led to an inhibitory effect on incorporation and uptake of radiolabeled precursors thymidine, uridine, leucine, and N-acetyl-glucosamine after 30 min of treatment. Furthermore, a clear release of UV-absorbing material and leakage of intracellular potassium were also detected. These findings, coupled with the high lipophilicity of these molecules, shown by high ClogP values, suggest that 8-EPI and pristimerol are able to interact within the lipid bilayer and as a consequence cause functional alterations on the cytoplasmic membrane of S. epidermidis cells.
Departamento de Microbiología y Biología Celular, Facultad de Farmacia, Universidad de La Laguna, Tenerife, Canary Islands, Spain.
Manuel R
MR
López
Leandro
L
de León
Laila
L
Moujir
D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D029753:Celastraceae / Q000737:chemistry*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D013212:Staphylococcus epidermidis / Q000187:drug effects* / Q000378:metabolism; D014315:Triterpenes / Q000737:chemistry / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D010636:Phenols; D010936:Plant Extracts; D014315:Triterpenes