3,4-DHPEA-EA from Olea Europaea L. is effective against standard and clinical isolates of Staphylococcus sp.

BACKGROUND: The aim of the present work was to evaluate the antibacterial effect of 3,4-DHPEA-EA (methyl-4-(2-(3,4-dihydroxyphenethoxy)-2-oxoethyl)-3-formyl-2-methyl-3,4-dihydro-2H-pyran-5-carboxylate), a derivate of oleuropein, against a range of Gram-positive bacteria, including ATCC strains, food and clinical isolates. METHODS: The minimum inhibitory concentrations (MICs) of 3,4-DHPEA-EA were determined by the broth microdilution method and the Bioscreen C. RESULTS: 3,4-DHPEA-EA was effective against ATCC and clinical isolates of Staphylococcus aureus (MIC values between 125 and 250 μg/ml) and ATCC and clinical isolates of Staphylococcus epidermidis (MIC values between 7.81 and 62.5 μg/ml). No significant differences were observed between the two solvents (methanol and DMSO) used to dissolve 3,4-DHPEA-EA. CONCLUSIONS: The results obtained could be used to develop novel therapies for the treatment of skin infections. Further studies need to be performed to elucidate the formation of 3,4-DHPEA-EA by acid hydrolysis of oleuropein in the human stomach.