Study On The Effect Of Drying Temperature On Metabolites In Salvia Miltiorrhiza Bunge Based On Metabolomics And Molecular Network

Salvia miltiorrhiza Bunge is perennial herb of the Labiatae family.Its dry roots and rhizomes are one of the bulk medicinal materials on the market in China.The postharvest drying of fresh S.miltiorrhiza is a key factor affecting the quality of S.miltiorrhiza.The change of temperature can affect drying efficiency,promote degradation and transformation of active ingredients,and then affect medicinal value and economic value of S.miltiorrhiza.In this study,S.miltiorrhiza was used as research materials.After S.miltiorrhiza was treated by different drying methods,the content of phenolic acids,tanshinones and other important components in the roots of S.miltiorrhiza was analyzed by molecular network and metabolomics.The reaction mechanism of the content change was discussed,and the best conditions for the drying and processing of S.miltiorrhiza were obtained and optimized,so as to reduce the loss of effective components.The key components affecting potential pharmacological effects under different temperature treatments were obtained by combined analysis of metabolomics and network pharmacology.It provides theoretical research support for the innovation of processing technology of Chinese medicinal materials,and lays a foundation for promoting the highquality development of Chinese medicinal materials and industry.The following are the study’s main findings:1.Molecular network construction of metabolites in S.miltiorrhizaThe molecular network based on mass spectrometry data was constructed,and it was found that tanshinones with the same functional group were closer in the molecular network.Fingerprint prediction technology was used to assist the qualitative analysis of unknown substances,and it was found that the mass spectrometry fragmentation rules of most salvianolic acids were consistent.Finally,34 tanshinones and 31 salvianolic acids were detected in S miltiorrhiz,and the mass spectrometry fragmentation rules such as characteristic ion fragments and neutral mass loss of different kinds of compounds were summarized.2.Differences in metabolomics of S.miltiorrhiza under different drying temperaturesA total of 437 metabolites were analyzed by metabolomics,including 11 different types of substances.The established metabolomics method was used to analyze the expression and differences of metabolites in samples treated at different temperatures.Metabolomics analysis showed that temperature had a significant effect on the metabolic components(carbohydrates,amino acids,phenolic acids,diterpene quinones and flavonoids)in S.miltiorrhiza during drying.During the drying process of S.miltiorrhiza,the changes of metabolites formed different quality differences.3.Differences in active ingredients of S.miltiorrhiza under different drying temperaturesBy expanding the post-harvest drying temperature range(45–150 ℃),100 ℃ was unambiguous found to be the key turning point for metabolite profiling change in S.miltiorrhiza,which were dominated by enzymatic catalytic biosynthesis(≤100 ℃)and chemical induced transformation(≥100 ℃),respectively.HD100 processing can save more salvianolic acids and tanshinones.4.Changes in appearance and composition of S.miltiorrhiza during dryingThe red degree of S.miltiorrhiza powder after crushing is positively correlated with the content of tanshinones.The drying rate of S.miltiorrhiza under high temperature environment was a deceleration process,and the drying rate was almost unchanged in the later stage.When the drying process was dominated by the loss of bound water,the tanshinone components would be transformed,resulting in changes in the content and proportion of tanshinone components in S.miltiorrhiza.Therefore,the drying should be stopped in time or the lower temperature should be selected to continue drying before the weight of S.miltiorrhiza tends to be stable.In this study,the effective components in S.miltiorrhiza were rapidly identified by molecular network technology,and the mass spectrometry fragmentation rules of effective components were summarized by constructing mass spectrometry fragment tree.It was found that 100 °C was the best temperature for drying S.miltiorrhiza.However,before the weight of S.miltiorrhiza tends to be stable during the drying process,it should be stopped in time or choose a lower temperature to continue drying,so as to prevent the chemical transformation of the effective components in S.miltiorrhiza,resulting in a change in the proportion of its active ingredients.The content changes of active ingredients under different temperature treatments affected the potential pharmacological effects of S.miltiorrhiza.The key differential components of low temperature drying were miltirone and ferulic acid,and the key differential components of high temperature drying were cryptotanshinone and danshensu.