Structure-fragmentation study of pentacyclic triterpenoids using electrospray ionization quadrupole time-of-flight tandem mass spectrometry (ESI-QTOFMS/MS)

Expanding annotation of chemical compounds in hawthorn fruits and their variations in thermal processing using integrated mass spectral similarity networking

Chemical structural characterization of chemical compounds from hawthorn fruits and its thermal processed products was carried out in present study. By linking Global Natural Products Social (GNPS) Molecular Networking and MolNetEnhancer workflow, seventy-four chemical compounds in hawthorn fruits and its thermal processed products were tentatively identified. Three quercetagetin derivatives (quercetagetin-3-O-glucoside, quercetagetin-di-glucoside and its isomer), five quercetin or kaempferol derivatives (quercetin-acetylapiosyl-hexoside, quercetin-3-O-(6″-malonyl-hexoside), quercetin-3-O-(6″-malonyl-hexoside)-(1 → 2)-O-hexoside, quercetin-3-O-(6″-malonyl-hexoside)-(1 → 2)-O-deoxyhexoside, kaempferol-3-O-(6″-malonyl-hexoside)), six procyanidins including four (E)C-ethyl-procyanidins and two A-type procyanidins digallate, as well as 13 triterpenoids including ursolic aldehyde, triterpenoid glycosides, and triterpene acids were reported for the first time in hawthorn fruits. In addition, triterpenoids exhibited considerable thermal stability, while all of flavonoid glycosides, proanthocyanidins and 10 in 13 organic acids showed dramatic decrease after thermal processing.

Qualitative and quantitative analysis of major components of Renshen-Yangrong Pill by UPLC-LTQ/Orbitrap/MS and UPLC-MS/MS

Renshen-Yangrong Pill (RYP) is a classical traditional Chinese medicine (TCM) preparation for the treatment of asthenic symptoms, while its multiple herbal compositions bring a wide variety of unclear chemical components which seriously hinder the effective quality control and clinical practice. The present study aimed to investigate the overall chemical profile of RYP by UPLC-LTQ/Orbitrap/MS, and further obtain the quantitative distributions of representing components in the preparations. A total of 132 components in RYP including flavonoids, triterpenoid saponins, phenylpropanoids, and monoterpenoid glycosides were identified or tentatively characterized by authentic compounds or accurate masses and fragmentation, in which 52 characteristic components were selected for further quantitation by UPLC-MS/MS. The assay was validated in terms of linearity, precision, repeatability, recovery and successfully applied for the quality control of 40 batches of RYP. Hesperidin and paeoniflorin were revealed as the most abundant constituents in RYP, and the samples of different origins and dosage forms were clearly classified based on hierarchical cluster analysis. This study provided a deep insight into the chemical profiling of RYP, as well as a new approach for determining the marker compounds, which laid a valuable foundation for further investigation of potential effective components and comprehensive quality control of RYP and related preparations.

Mass spectrometry DDA parameters and global coverage of the metabolome: Spectral molecular networks of momordica cardiospermoides plants

INTRODUCTION

Molecular networking (MN) has emerged as a key strategy to organize and annotate untargeted tandem mass spectrometry (MS/MS) data generated using either data independent- or dependent acquisition (DIA or DDA). The latter presents a time-efficient approach where full scan (MS¹) and MS² spectra are obtained with shorter cycle times. However, there are limitations related to DDA parameters, some of which are (i) intensity threshold and (ii) collision energy. The former determines ion prioritization for fragmentation, and the latter defines the fragmentation of selected ions. These DDA parameters inevitably determine the coverage and quality of spectral data, which would affect the outputs of MN methods.

OBJECTIVES

This study assessed the extent to which the quality of the tandem spectral data relates to MN topology and subsequent implications in the annotation of metabolites and chemical classification relative to the different DDA parameters employed.

METHODS

Herein, characterising the metabolome of Momordica cardiospermoides plants, we employ classical MN performance indicators to investigate the effects of collision energies and intensity thresholds on the topology of generated MN and propagated annotations.

RESULTS

We demonstrated that the lowest predefined intensity thresholds and collision energies result in comprehensive molecular networks. Comparatively, higher intensity thresholds and collision energies resulted in fewer MS² spectra acquisition, subsequently fewer nodes, and a limited exploration of the metabolome through MN.

CONCLUSION

Contributing to ongoing efforts and conversations on improving DDA strategies, this study proposes a framework in which multiple DDA parameters are utilized to increase the coverage of ions acquired and improve the global coverage of MN, propagated annotations, and the chemical classification performed.