Discriminant Analysis Of Natural Agarwood Formation Mode And Study On Classification Of Commercial Specifications Of Agarwood

Agarwood,the resins of Aquilaria sinensis(Lour.)Gilg,is one of the traditional precious Chinese medicines.The A.sinensis is a damage-inducing plant.The A.sinensis are only likely to produce agarwood when get injured.Under field conditions,the A.sinensis are wounded by lightning strike,wind break,insect attack and so on to promote the formation of agarwood,and the agarwood are called natural agarwood.By human intervention,the A.sinensis are induced by physical injury(chopping,etc.),chemical simulation(injection of chemical reagents,etc.),fungal infection(injection of fungal fermentation broth,etc.),and comprehensive stimulation(chemical simulation combined with fungal infection,etc.)to promote the formation of agarwood,and the agarwood are called artificial agarwood.Commercially available agarwood is an agarwood that complies with Chinese Pharmacopoeia.It can be natural agarwood or artificial agarwood.In this study,fingerprints of natural agarwood and artificial agarwood with different origins and different induction methods are constructed based on GCMS.The artificial agarwood with four known induction methods is used as the training set to establish a random forest model to discriminate and analyze the natural agarwood formation mode.The results showed that 57.1% of natural agarwood were likely to be induced by comprehensive stimulation;22.9% were induced by chemical stimulation;17.1% were induced by physical injury;2.9% were induced by fungal infection.The results of PCA and PLS-DA analysis of the XCMS data sets extracted by natural agarwood GC-MS showed that natural agarwood can be divided into three groups: comprehensive stimulation(R <0.9)and chemical stimulation(R <0.9),comprehensive stimulation(R> 0.9)and physical injury,fungal infection and chemical stimulation(R> 0.9).The results showed that comprehensive stimulation was the main formation mode of natural agarwood,and the artificial agarwood which was close to the natural agarwood can be efficiently induced by comprehensive stimulation.Isoaromadendrene epoxide,?-eudesmol,viridiflorol,guaiol,caryophyllene oxide,aristolone,longifolenaldehyde and vellerdiol might play important roles in the formation process of agarwood induced by comprehensive stimulation and chemical stimulation.In this study,the random forest model was used to discriminate and analyze the formation mode of natural agarwood,and the results showed the most of natural agarwood were induced by comprehensive stimulation,and artificial agarwood which was similar to the natural agarwood can be induced by comprehensive stimulation,which provided a theoretical basis for the development of high-efficiency induced agents and study on the mechanism of natural agarwood.To classify the specifications of agarwood,a total of 38 batches of natural agarwood samples,1 reference crude drug and 59 batches of artificial agarwood were collected in this study.Correlation analysis,univariate binary logistic regression analysis and K-mean clustering analysis were used to investigate the physicochemical identification of terpenoids,alcohol-soluble extraction content(T),GC-MS chromatographic fingerprint apparent abundance and the internal relationship between the common components of GC-MS chromatographic fingerprint of agarwood.The results showed that the content of alcohol-soluble extraction was significantly related to the content of ?-eudesmol,ledol and aristolone(P<0.05).According to the content of alcohol-soluble extraction,agarwood were divided into three grades(Grade ?: T?30.0%;Grade ?: 30.0%>T?20.0%;Grade ?: 20.0%>T?10.0%).The content of alcoholsoluble extraction can be used as an index for grading agarwood,and GC-MS chromatographic fingerprint similarity can be used as an index for grading standards.This study combined the existing agarwood commodity classification standards and formulated the quality standards for agarwood commodity medicinal materials to order and rationalize the market price of agarwood commodity medicinal materials to meet market demand.To explore the correlation between the grade and the formation mode of agarwood,discrimination and analysis of 38 batches of natural agarwood in chapter ? would be conducted by using the random forest model established in chapter ?.And based on 97 batches of agarwood in chapter ?,the correlation analysis between agarwood commodity grade and its formation mode was carried out.The results showed that in Grade ?,50.0% of agarwood were induced by comprehensive stimulation and 50.0% were chemical stimulation;in Grade ?,64.3% were comprehensive stimulation,32.1% were chemical stimulation,and 3.6% were fungal infection;in Grade ?,61.0% were comprehensive stimulation,25.4% were the chemical stimulation,6.8% were physical injury,and 6.8% were fungal infection.There was a significant correlation between the classification and the formation mode of fungal infection(P <0.05).As the grade decreased,the proportion of the fungal method also decreased.In this study,the correlation between the grade of agarwood and its formation mode was analyzed,and the results showed that the classification of agarwood was significantly correlated with the formation mode of fungal infection,which provided a theoretical basis for the development of highly effective artificially induced agarwood.