A study on antimicrobial activity and chemical compositions of Essential oils from flowers of lavandula anguifolia and salvia officinalis

chemical compositions  and antimicrobial effects on E.coli and S.aureus of essential oils from lavandula anguifolia and salvia officinalis were stuied.disk diffusion method was conducted to evaluate the zone of microbial growth inhibition at ۱,۱:.۲,۱:.۸ and ۱:۱۶ dilutions of the essenial oils at four stages of zero(fresh oil).۱,۲ and ۳ months post-exeaction.the antimicrobial effect was also studied against ۱۰_۷ ml.۱۰_۶ ml amd ۱۰_۵ml concentrations of microbial cells to find out minimal inhibitory concentration(MIC) and minimal Bactericidal concentration(mbc).the Essential oils were bactericidal against both the micro organisms.comparatively,Gram negative bacterium E.coli,was readily affected by the  Essential oil of lavandula anguifolia and S.aureus was redily affected by the Essential oil of salvia officinalis.chemical compositions of Essential oils  were analyzed by Gas chromatography and Mass spectrometry(GC and GC/MS). twelve common chemical compounds of A-Humulene,a-pinene,B-pinene,a-thujene,۱,۸-camphor,Cis-B-ocimene,Linalool,P-Cymene and Terpinene-۴-ol were found at various concentrations in both the oils,most of which were monoterpenes.Major components of Essential oil of  salvia officinalis were B-pinene(۱۶%),Berneol(۹.۴%),Glubulol(۹.۳%),a-humulene(۸.۴%),a-thujene(۶.۴%),a-pinene(۵.۵%),Camphene(۵%), and those of lavandula anguifolia were linalol(۳۶.۹%),۱,۸-Cineole(۱۶%),B-orneol(۱۱.۵%),canphor(۴.۲%) and terpinene-۴-ol (۴.۱۹%) It seems that monoterpenes give antibacterial property to the essential oils.

Keywords:

lavandula anguifolia , Salvia Officinalis , Antimicrobial , Essential oils