Chemical Constitutes And Antibacterial Activity Of Essential Oils From Pyrrosiae Folium

Objective: The present study aimed to analyze the chemical components of essential oils from Pyrrosiae Folium, and compare the differences of the oils from different habitats and species. In addition, in vitro antibacterial activities of these oils were also evaluated in this study.Methods: The materials used were bought from the herb markets and collected in the field. Conventional hydrodistillation was used for extracting essential oil and the chemical compositions of the oils were analyzed by Gas Chromatography-Mass Spectrometry(GC-MS). Components of the oils were confirmed finally by checking the retention index with those recorded in literatures and area normalization method was applied to get the proportion of any component. Principal component analysis(PCA) and Cluster analysis(CA) were used to analyse the relationship of the pyrrosia herbs from different habitats and species. In vitro antibacterial properties were evaluated by minimum inhibitory concentration(MIC) and minimum bactericidal concentration(MBC), which were obtained by microdilution method and plate cultivation method.Results: The major components of the essential oils from Pyrrosiae Folium were 2, 4-Pentadienal(5.3-34.9%), trans-2-Hexenal(0.8-20.4%),Nonanal(3.3-16.4%),3, 7, 11, 15-Tetramethyl-2-hexadecen-1-ol(4.5-16.1%), 1-Hexanol(0.5-12.5%), trans, trans-2, 4-Heptadienal(0.3-11.9%), trans, cis-2, 4-Heptadienal(0.3-7.7%) and the major chemical classifications were Aldehydes(26.1-46.5%), Diterpenoids(4.5-16%), Alcohols(2.1-23%), Monoterpenes(0.4-13.9%), Hydrocarbons(0.5-12.7%). The MIC and MBC of the essential oils from different Pyrrosia samples were 2.5-20 ?L·m L-1, 2.5-40 ?L·m L-1 or not determined separately.Conclusions:The chemical components of the essential oils from different Pyrrosia samples show a great similarity, and the differences between Pyrrosia species are not significant, the compositions of the oils were related to the sources and habitates of these materials partly. Essential oils from Pyrrosiae Folium displayed certain extent antibacterial activities in the study. The results of this study provided theoretical basis for further development and utilization of Pyrrosiae Folium.