Comparison of the active components of Aster tataricus from different regions and related processed products by ultra‐high performance liquid chromatography with tandem mass spectrometry

Chemotaxonomy of Aster species from the Qinghai-Tibetan Plateau based on metabolomics

INTRODUCTION

The genus Aster plants have been widely used for thousands of years in the Qinghai-Tibetan Plateau for the clearing of heat, detoxification, and the treatment of seasonal pandemic diseases. Although the presence of several flavonoid compounds in Aster has been reported by previous studies, the diversity of secondary metabolites within and among species is relatively unknown.

OBJECTIVE

The metabolite profile of one Aster species was systematically compared with those of other taxa to find potential chemotaxonomic markers, delimit species, and assess chemodiversity.

METHOD

Samples of the above-ground parts of 11 Aster species were collected and their metabolites were analysed by ultra-high performance liquid chromatography with photodiode array detection and quadrupole time-of-flight tandem mass spectrometry. Unsupervised principal component analysis, supervised orthogonal partial least-squares discriminant analysis, heatmap analysis, and hierarchical cluster analysis were employed to analyse 95 representative samples from 11 Aster species and determine species-specific chemical markers based on a metabolomics database.

RESULTS

Six phenolic acids and flavonoids were detected and quantified in all Aster species, suggesting that these compounds may be common constituents in the Aster genus. Metabolite analysis showed terpenoid compounds to be potential chemical markers for interspecies differentiation. Ent-kaurane-type diterpenoid glycosides were the main class of compounds in all Aster species except for A. farreri, which mainly contained oleanane-type pentacyclic triterpenoids. Diterpenoid glycosides were low-content chemotaxonomic markers and were detected for the first time in Aster species from the Qinghai-Tibetan Plateau.

CONCLUSION

Chemotaxonomy and metabolomics were used to support the phylogenic relationships of the Aster genus.

Comparison of the chemical profile differences of Aster tataricus between raw and processed products by metabolomics coupled with chemometrics methods

Aster tataricus, a traditional Chinese herb, has been used to treat cough and asthma for many years. Its raw and processed products have different pharmacological effects in clinical applications. To explore the chemical profile differences of components in A. tataricus processed with different methods, metabolomics methods based on ultra-high-performance liquid chromatography coupled with quadrupole time of flight mass spectrometry and gas chromatography-mass spectrometry were developed. Chemometrics strategy was applied to filter and screen the candidate compounds. The accuracy of differential markers was validated by back propagation neural network. The established methods showed that raw A. tataricus, honey-processed A. tataricus, vinegar-processed A. tataricus, and steamed A. tataricus were clearly divided into four groups, suggesting that the components were closely related to the processing methods. A total of 64 nonvolatile and 43 volatile compounds were identified in A. tataricus, and 22 nonvolatile and 12 volatile differential constituents were selected to distinguish the raw and processed A. tataricus. This study demonstrated that the metabolomics methods coupled with chemometrics were a comprehensive strategy to analyze the chemical profile differences and provided a reliable reference for quality evaluation of A. tataricus.