A two-step approach for systematic identification and quality evaluation of wild and introduced Anemone flaccida Fr. Schmidt (Di Wu) based on DNA barcode and UPLC-QTOF-MS/MS

An integrated strategy of MS-network-based offline 2DLC-QTOF-MS/MS coupled with UHPLC-QTRAP®-MS/MS for the characterization and quantification of the non-polysaccharides in Sijunzi decoction

Sijunzi decoction (SJZD), a classic recipe in traditional Chinese medicine (TCM), has been applied for the clinical treatment of gastrointestinal diseases. While there are reports on pharmaceutical substances of SJZD focusing on its polysaccharides, the composition of non-polysaccharides (NPSs) has not yet been holistically clarified. In the current study, offline two-dimensional liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (2DLC-QTOF-MS/MS) was used for comprehensive NPS chemical profiling of SJZD. In addition, the MS-network of SJZD was proposed, which led to the construction of a larger in-house chemical library and accelerated qualitative processing. Four hundred forty-nine components, among which 6 were potentially novel, and 32 were confirmed by standard substances, were identified or tentatively assigned. Furthermore, based on good method validation, 19 representative components were simultaneously quantified by ultra-high-performance liquid chromatography coupled with triple-quadrupole linear ion-trap tandem mass spectrometry (UHPLC-QTRAP®-MS/MS). They were selected for quantification on the account of their bioactive reports on in vivo or in vitro activities, the peak intensity in the mass spectrum, and characteristic structures, which have the potential to be qualitative or quantitative markers of SJZD. The present work furthers understanding of the pharmacological effects and action mechanism of NPSs in SJZD, and provides a useful analytical approach for complex composition research of TCMs.

Marker peptide screening and species-specific authentication of Pheretima using proteomics

Pheretima is a common and valuable animal-derived medication used in traditional Chinese medicine. There are four species of Pheretima specified in the Chinese Pharmacopoeia (2015 edition), i.e. Pheretima aspergillum, P. vulgaris, P. guillelmi, and P. pectinifera. A recent report revealed ~ 55% of Pheretima in the commercial marketplace may be adulterated by other species, contrary to the Pharmacopoeia standard. The safety, efficacy, and authenticity of Pheretima is an important issue. Currently, the availability of specific quality-markers for the various species and effective identification methods are still limited. In this study, label-free quantification proteomics of species from Pheretima and Amynthas was carried out using nanoscale liquid chromatography coupled to tandem mass spectrometry (nano LC-MS/MS), and marker peptides were identified based on their ion intensities using multivariate data analysis (principal component analysis and supervised partial least-squares discriminant analysis). A total of 48,476 peptides with high confidence corresponding to 13,397 proteins were identified from all samples. The marker peptides were validated by comparison with synthetic peptide reference standards using LC-MS/MS operating in a multiple-reaction monitoring mode. A multiple-peptide identification strategy was proposed for the authentication of Pheretima and subsequently applied to samples obtained from retail outlets in various regions of China. The results showed that eight out of the 15 samples tested were deemed authentic Pheretima.