Studies On The Chemical Constituents And Insecticidal Activities Of Essential Oils From Five Species Of Ajania Poljak And Their Taxonomic Significance

In this study,the essential oils of five species of plants of Ajania Poljak(Ajania fruticulosa,Ajania nematoloba,Ajania przewalskii,Ajania remotipinna,Ajania tenuifolia)were extracted by water distillation,and the chemical components of the essential oils were analyzed by gas chromatography-mass spectrometry(GC-MS),the chemical constituents of essential oil of A.Remotipinna were reported for the first time.Studies have shown that the essential oil has certain systematics value,and the insecticidal activity of the essential oil is related to its components.The biological activity of essential oils from A.przewalskii and A.remotipinna were investigated,and the components of plants of Ajania Poljak were analyzed by SPSS cluster analysis and comparative analysis,the purpose of this paper is to explore the significance of systematics,and to conduct basic research on the development.The main conclusions are as follows:(1)A total of 98 essential components were isolated and identified from the essential oils of 5 species of Ajania Poljak,including 26 species of A.fruticulosa,31 species of A.nematoloba,31 species of A.przewalskii,48 species of A.remotipinna and 51 species of A.tenuifolia.There are only 7 common components in the five plant essential oils.The number of unique components varied greatly.48 components were identified from A.Remotipinna,the main components areβ-phellandrene,eucalyptol,thujone,sabinene,etc.There were 6 common components in 3 populations,which had 6,13 and 9 unique components respectively.Each population contained monoterpenoids and sesquiterpenoids,and monoterpenoids were the main components of essential oil.In summary,the essential oils of 5 species of Ajania Poljak have both common components and unique components among different species and populations of the same species.(2)In this paper,we collected more than 3 populations of Ajania Poljak plants,which are A.Fruticulosa,A.Remotipinna,A.Tenuifolia,and used SPSS 22.0software to analyze the correlation between the contents of common components in the three essential oils and the altitude,latitude and longitude.The results showed that α-terpineol in essential oil from A.Fruticulosa was negatively correlated with altitude,and the content of eucalyptol in essential oil from A.Remotipinna was negatively correlated with altitude,and the content of β-pinene was positively correlated with longitude,there was a significant positive correlation between the content of camphor and latitude in A.Tenuifolia,which provided data support for the future research and development of the essential oil of Ajania Poljak.(3)The components of essential oils from these plants are not sufficient for a comprehensive chemical classification of Ajania Poljak,but they still have some taxonomic value.The results of cluster analysis showed that the main components and contents of the essential oils from the plants of Ajania Poljak had obvious geographical regions.flavonoids and phenylpropanoids can reflect the taxonomical relationship of Ajania Poljak in some degree at the level of species.The similarity of chemical constituents of the Ajania Poljak plants essential oils can be used as a basis for judging the relationship between the Ajania Poljak plants.The evolutionary relationships among different compounds can reveal the phylogenetic relationships among species to some extent.The phylogenetic relationships among several species of Ajania Poljak were further revealed at molecular level.To some extent,it supports the conclusion that A.fruticulosa and Ajania nematoloba are closely related,and that A.przewalskii,A.remotipinna and A.tenuifolia are closely related.(4)The contact,fumigation and repellent activities of A.przewalskii and A.remotipinna on Tribolium castaneum were studied.The results showed that the essential oils of A.przewalskii and A.remotipinna had good insecticidal activity and repellent activity to adult and larvae of T.castaneum,while the essential oils of A.przewalskii and A.remotipinna had weak fumigation activity to adult of T.castaneum.Different populations of A.remotipinna have different biological activities because of the differences in composition.