Abstract

Forty polar and non polar extracts from six “Montado” species (Adenocarpus anisochilus., Erica lusitanica, Lavandula stoechas subsp. luisieri, Paeonia broteroi, Quercus fagineasubsp. broteroi  and Rosmarinus officinalis) were evaluated for their antimicrobial activity against a broad panel of microorganisms that include standard and resistant strains of Gram-positive, Gram-negative bacteria, Mycobacterium smegmatis and the yeast Candida albicans. From the forty tested extracts, 87% inhibited the development of Gram-positive bacteria. Interesting results were obtained with the most polar extracts of P. broteroi (leaves) displaying the best MIC (3.1 to 1.9 µg/ml) when tested against Staphylococcus aureusstandard, Vancomycin-Resistant S. aureus VRSA and meticillin-resistant S. aureus (MRSA) strains. The extracts of E. lusitanica and P. broteroi displayed the broadest antimicrobial activity spectra with the lowest minimum inhibitory concentration (MIC) values seeming very promising and are worthy for further phytochemical studies.

Key words: “Montado” flora, antibacterial activity, MIC determination, phytochemical screening.