Synergistic effect of the antibacterial compound 23-methyl-6-O-desmethylauricepyrone isolated from Achyrocline satureioides

JORAY M.B.; PALACIOS S. M.; CARPINELLA M. C.*

Córdoba

Otro; 1° Reunión Internacional de Ciencias Farmacéuticas.; 2010

Introduction Staphylococcus aureus causes a wide range of infectious diseases in humans (1) from relatively mild skin infections such as folliculitis and furunculosis to life-threatening conditions, including sepsis, deep abscesses, pneumonia, osteomyelitis, and infective endocarditis (2). As a result of a study of the antibacterial activity of Achyrocline satureioides a bioactive compound was identified. A remarkable inhibitory effect of this compound on the mentioned pathogenic bacterium was determined. Then, the antibacterial activity of combinations of this active principle with subinhibitory concentrations of commercial antibiotics was investigated. Materials and methods The structural elucidation of the isolated compound was achieved through different spectroscopic techniques. The MIC, MBC and synergistic studies were carried out by micro dilution test in agar according to CLSI (3) against Staphylococcus aureus (ATCC 6538) used as reference. Results The most active compound present in A. satureioides extract was identified as 23-methyl-6-O-desmethylauricepyrone (1). The MIC and MBC values of this compound and of commercial antibiotics are shown in Table 1. Table 2 and 3 show the results obtained in synergistic assays with erythromycin and gentamicin, respectively.