柠檬香蜂草精油的气相色谱-质谱联用分析及抑菌活性研究

该文采用水蒸气蒸馏萃取法(steam distillation,SD)对柠檬香蜂草提取精油,气相色谱-质谱联用(gas chromatograph-mass spectrometry,GC-MS)分析精油成分,制备成不同体积分数稀释液,通过纸片扩散法(kirby-bauer,K-B)测定柠檬香蜂草精油对3种食源性致病菌(金黄色葡萄球菌、大肠杆菌、四联球菌)的药物敏感性,筛选敏感菌株,最后稀释涂布平板法测定半数抑制浓度(50%inhibitory concentration,IC 50)。测得柠檬香蜂草精油中脂肪族占25.91%,芳香族占20.16%,萜类占53.93%。且其对金黄色葡萄球菌抑制作用最弱,对四联球菌抑制作用最强,在实验浓度范围内,抑制强度随精油浓度升高而升高,经计算,柠檬香蜂草精油对四联球菌的IC 50为457μg/mL。最终判断柠檬香蜂草精油对四联球菌有较好抑制作用,且起抑菌作用的物质为β-石竹烯、香茅醇和柠檬醛。

GC-MS analysis of lemon balm essential oil and its anti-pathogen activity

To expand natural food additives in replacement of chemicals,steam distillation was applied to extract essential oil of lemon balm,followed by gas chromatography-mass spectrometry(GC-MS)to clarify components of the essential oil.After dilution,an antimicrobial screening was performed with three pathogenic bacteria(Staphylococcus aureus,Escherichia coli,Micrococcus tetragenus)using kirby-bauer method.IC 50 was determined by dilution plating procedure subsequently.The results showed that the 25.91%of lemon balm essential oil were aliphatic compounds,20.16%were aromatic compounds and 53.93%were terpenoids.The lemon balm essential oil showed the weakest inhibition on S.aureus and the strongest inhibition on M.tetragenus.The inhibition intensity increased with the concentration of essential oil.The IC 50 of lemon balm essential oil to M.tetragenus was 457μg/mL.The essential oil of lemon balm had strong inhibitory effect on M.tetragenus,and the antimicrobial components were caryophyllene oxide,citronellal and 2,6-octadienal,3,7-dimethyl.