Tibetan Artemisia Six Essential Oils And Fine Paste Extraction, Analysis Of Chemical Composition And Antibacterial Effects

There are about 60 Artemisia species in Tibet,including 15 endemic species,which are the founders or main members of the local vegetation and could be used as medicine and food.Some species are suitable for grazing livestock,while others growing in arid and frigid environments such as mountains and deserts are pioneer or accompanying plants of forests.Artemisia species always contain volatile oils,fatty acids,organic acids and alkaloids, whose main elements are polyacetylenes,flavonoids,terpenoids and some other compounds, like sesquiterpene lactones.Moreover,cyanogenic glycosides,flavonol,coumarin and interferon inducers are also found in few species.Normal content of essential oils in Artemisia species is 0.3-1.3%,with an average of approximately 0.5%.These oils are useful in diminishing inflammation,killing pests,sterilization and aromatherapy.In this study,the chemical composition of essential oils from A.younghusbandii J.R.Drumm.ex Pam R,A.rutifolia Steph.ex Spreng.,A.yadongensis Ling et Y.B.Ling.,A.stracheyi Hook.f.et Thorns.ex C.B.Clarke and two uncertain species A.sp-Lhasa & Yadong collected from Tibet were analyzed by GC-MS.A total of 69 compounds were identified:42 of them were from A.sp-Lhasa;53 from A.younghusbandii; 45 from A.rutifolia;44 from A.sp-Yadong's leaves and 45 from its stem;48 from A. yadongensis;51 from A.stracheyi's flowers and leaves,46 from its stem.The essential oils of A.rutifolia,A.yadongensis,A.stracheyi,A.younghusbandii, A.sp-Lhasa and A.sp-Yadong were evaluated for antibacterial activities by using the value of minimum inhibitory concentrations(MIC) against five different bacteria,which are Staphylococcus epidermidis,S.aureus,Enterococcus faccalis,Bacillus subtilis and Escherichia coli,and one fungus Cryptococcus neoformans in the 96-well plates.This research provides academic support for the development of new efficient drugs and antimicrobials with low toxicity,as well as providing further evidence supporting the protection of plant resources in Tibet.