CHEMICAL COMPOSITION AND ANTIBACTERIAL ACTIVITY OF ESSENTIAL OILS OF THREE SALVIA SPECIES, WIDESPREAD IN EASTERN ROMANIA

Essential oils of Salvia aethiopis L., S. nemorosa L. and S. verticillata L. were investigated in terms of chemical composition and antibacterial activity and tested on two pathogen bacterial strains: Staphylococcus aureus and Escherichia coli. Essential oils obtained by hydro-distillation were analyzed using GC-MS method. Chemical composition revealed 45 components present in the three species: 29 compounds in S. verticillata sample, 12 in S. aethiopis ones and 24 respectively in S. nemorosa sample, representing 99.7% of the oil composition, 99.3% and 95% respectively. The volatile compounds identification was made using the NIST spectral bank and Kovats indexes. Then, the percentages of compounds of each oil are summarized. The minimal inhibitory concentration (MIC) was determined by diffusion method and successive micro-dilutions. It was noticed that the dilution method is much more precise. Test results have shown a greater antibacterial effect of Salvia oil samples against Gram positive, than the Gram negative bacteria.