Analysis Of Aroma Components Of Osmanthus Pure Dew And Study On Antibacterial Activity Of Linalool

Part 1 Analysis of volatile components of Osmanthus fragrans Hydrosol from different producing areas based on GC/MSOsmanthus fragrans Lour from Xianning,Chizhou,Fanchang,and Changde were used as raw materials to prepare Osmanthus fragrans.The volatile components in Osmanthus fragrans from four different producing areas were analyzed and identified by gas chromatography-mass spectrometry(GC/MS).The results showed that 46 components and6 differential components were identified in Xianning,Chizhou,Fanchang,and Changde.The main aroma substances are linalool and its oxides?-Caprolactone,?-Ionone,geraniol,etc.The components can be divided into alcohols,terpenes,ketones,alkanes,phenols,aldehydes,and esters.The volatile components in Osmanthus fragrans Hydrosol are mainly alcohols,ketones,and esters.The relative content of alcohols is 64.80%-73.33%,the relative content of ketones is 9.06-17.07%,followed by the relative content of esters is8.28%-14.17%.Osmanthus fragrans Hydrosol from different producing areas has similar aroma components and different contents.The volatile aroma components of Osmanthus fragrans Hydrosol from Xianning are more abundant than those from the other three producing areas.Part 2 Antibacterial mechanism of linalool against Staphylococcus aureusThe MIC value of linalool against Staphylococcus aureus was determined,and the antibacterial mechanism of linalool against Staphylococcus aureus was preliminarily explored.The results of 8-phenylamino-1-naphthalenesulfonic acid fluorescent probe(ANS)showed that linalool could damage the cell wall and expose the hydrophobic groups on the cell membrane surface;the results of DNA molecular gel electrophoresis showed that with the concentration and time,the intracellular DNA content gradually decreased;the UV spectrophotometer measured the cell supernatant OD₂₆₀,the results show that linalool treatment can enhance the cell membrane permeability,DNA molecule pass rate enhancement,a large amount of nucleic acid material leakage;SDS-PAG protein electrophoresis results showed that 20?l/ml linalool treatment for 2h could significantly reduce the protein content in the bacteria;Coomassie blue determined the extracellular protein content,and the results showed that the extracellular water-soluble protein content gradually increased with the increasing concentration and time of drug administration;The results of IR spectrum analysis of bacterial protein showed that the secondary structure of bacterial protein changed after linalool treatment,which may lead to the change of function.The above results show that linalool changes the cell membrane permeability by binding the cell membrane protein,making the macromolecular substances leak out and affecting the normal growth,thus producing the antibacterial effect.Linalol has a significant antibacterial effect on S.aureus and is expected to develop a novel natural antibacterial agent.