Rapid authentication of different herbal medicines by heating online extraction electrospray ionization mass spectrometry

The rapid and accurate authentication of traditional Chinese medicines(TCMs)has always been a key scientific and technical problem in the field of pharmaceutical analysis.Herein,a novel heating online extraction electrospray ionization mass spectrometry(H-oEESI-MS)was developed for the rapid and direct analysis of extremely complex substances without the requirement for any sample pretreatment or pre-separation steps.The overall molecular profile and fragment structure features of various herbal medicines could be completely captured within 10–15 s,with minimal sample(<0.5 mg)and solvent consumption(<20μL for one sample).Furthermore,a rapid differentiation and authentication strategy for TCMs based on H-oEESI-MS was proposed,including metabolic profile characterization,characteristic marker screening and identification,and multivariate statistical analysis model validation.In an analysis of 52 batches of seven types of Aconitum medicinal materials,20 and 21 key compounds were screened out as the characteristic markers of raw and processed Aconitum herbal medicines,respectively,and the possible structures of all the characteristic markers were comprehensively identified based on Compound Discoverer databases.Finally,multivariate statistical analysis showed that all the different types of herbal medicines were well differentiated and identified(R^(2)X>0.87,R^(2)Y>0.91,and Q^(2)>0.72),which further verified the feasibility and reliability of this comprehensive strategy for the rapid authentication of different TCMs based on H-oEESI-MS.In summary,this rapid authentication strategy realized the ultra-high-throughput,low-cost,and standardized detection of various complex TCMs for the first time,thereby demonstrating wide applicability and value for the development of quality standards for TCMs.

Functional identification of the terpene synthase family involved in diterpenoid alkaloids biosynthesis in Aconitum carmichaelii

Aconitum carmichaelii is a high-value medicinal herb widely used across China,Japan,and other Asian countries.Aconitine-type diterpene alkaloids(DAs)are the characteristic compounds in Aconitum.Although six transcriptomes,based on short-read next generation sequencing technology,have been reported from the Aconitum species,the terpene synthase(TPS)corresponding to DAs biosynthesis remains unidentified.We apply a combination of Pacbio isoform sequencing and RNA sequencing to provide a comprehensive view of the A.carmichaelii transcriptome.Nineteen TPSs and five alternative splicing isoforms belonging to TPS-b,TPS-c,and TPS-e/f subfamilies were identified.In vitro enzyme reaction analysis functional identified two sesqui-TPSs and twelve di TPSs.Seven of the TPS-c subfamily genes reacted with GGPP to produce the intermediate ent-copalyl diphosphate.Five Ac KSLs separately reacted with ent-CPP to produce ent-kaurene,ent-atiserene,and ent-13-epi-sandaracopimaradie:a new diterpene found in Aconitum.Ac TPSs gene expression in conjunction DAs content analysis in different tissues validated that ent-CPP is the sole precursor to all DAs biosynthesis,with Ac KSL1,Ac KSL2 s and Ac KSL3-1 responsible for C20 atisine and napelline type DAs biosynthesis,respectively.These data clarified the molecular basis for the C20-DAs biosynthetic pathway in A.carmichaelii and pave the way for further exploration of C19-DAs biosynthesis in the Aconitum species.