Study On Difference Comparison And Transformation Of Active Components Of Radix Bupleuri

Objective:Radix Bupleuri is a traditional Chinese herb with a long history of medicinal use.Saikosaponins and volatile oils are the most active compounds in Radix Bupleuri.However,although the content of saikosaponins c(SSc)is high,the pharmacological activity is relatively weak.Radix Bupleuri quality varies,and Radix Bupleuri from different places of origin had a different quality.In this study,through high-performance liquid chromatography(HPLC),gas chromatography(GC)coupled with mass spectrometry(MS)and multiple reaction monitoring(MRM)mode,was used to analyze the North and South Radix Bupleuri samples from different regions.Multivariate statistical analysis was used to differentiate the Radix Bupleuri samples cultivated in different regions and to discover the differential compositions.And the quantitative analysis of five saikosaponins in Radix Bupleuri so as to evaluate the difference in the absolute content of saikosaponins attributable to the cultivation region.The findings may contribute to a deeper understanding of their differential chemical composition and the proper selection of Radix Bupleuri species and origin.Meanwhile,the chemical transformation method was adopted to convert SSc into rare saikosaponins with higher pharmacological activity by changing the metastructure of saponin,which provided theoretical support for the research and application of saikosaponins.Methods:1 Quantitative analysis and differential evaluation of North and South Radix Bupleuri cultivated in different regionsThe quality of Radix Bupleuri samples was assessed by the absolute contents of five saikosaponins,which were accurately quantified by an established HPLC-MRM/MS method.HPLC-MS,GC-MS and multivariate statistical analysis were employed to differentiate the North and South Radix Bupleuri samples cultivated in different regions and to discover the differential compositions.2 Chemical transformation product and pathway analysis of SScThe structure and transformation pathway of the products generated by the chemical transformation of SSc using dodeca phosphotungstic acid(12-HPW)was analyzed by HPLC coupled with Q Exactive-Orbitrap high resolution mass spectrometry(HRMS).Results:1 Quantitative analysis and differential evaluation of Radix Bupleuri cultivated in different regionsThe results of quantitative analysis showed that the cultivation region made a significant difference on the content of five saikosaponins.Through HPLC-MS and GC-MS combined with multivariate statistical analysis,it could be seen that differences between samples of Radix Bupleuri cultivated in different provinces,whereas samples from the same province showed a significant similarity to each other.Twentyeight saponins and fifty-eight volatile compounds were identified as differentially accumulated components that contributed significantly.2 Quantitative analysis and differential evaluation of North and South Radix Bupleuri cultivatedThe results of quantitative analysis showed that the content of saikosaponins in north Radix Bupleuri was higher than that in south Radix Bupleuri.Multivariate statistical analysis was used to further transform the obtained HPLC-MS and GC-MS data sets.The results showed that there were significant differences between the saikosaponins and volatile compounds of North and South Radix Bupleuri.Twenty-one saponins and fifty-two volatile components were identified as the main cumulative components causing the differences in the samples of Radix Bupleuri.3 Chemical transformation product and pathway analysis of SScIn acidic aqueous generated by 12-HPW,SSc was transformed to SSh with hetero-cyclodiene structure through cycloether ring-opening and hydroxyl elimination reactions at position C18 of aglycone,and was further transformed to derhamnose-SSc and derhamnose-SSh through deglycosylation reaction at position C3.The transformation was stabilized after 6 h reaction.Conclusion:1 Quantitative analysis and differential evaluation of North and South Radix Bupleuri cultivated in different regionsThis study established a relatively complete set of methods to study the difference in the composition and content of main effective components of Radix Bupleuri from different producing areas,which laid a foundation for a more comprehensive and systematic quality evaluation of Radix Bupleuri.2 Chemical transformation product and pathway analysis of SScThe employed HPLC-Q Exactive-Orbitrap method enables the rapid and accurate identification of saikosaponins and their transformation products,as well as differentiation of transformed cyclodiene isomers.At the same time,SSc was transformed from type I saponin to type II saponin containing isocyclodiene structure by 12-HPW conversion,which was helpful to improve the inhibitory activity of Na+,K+-ATPase and reduce hemolytic activity,which opened up a new direction for the study of pharmacological activity of saikosaponin.