Elucidation of the fragmentation pathways of a complex 3,7-O-glycosyl flavonol by CID, HCD, and PQD on an LTQ-Orbitrap Velos Pro hybrid mass spectrometer

LC-MS/DIA-based strategy for comprehensive flavonoid profiling: an Ocotea spp. applicability case

We introduce a liquid chromatography - mass spectrometry with data-independent acquisition (LC-MS/DIA)-based strategy, specifically tailored to achieve comprehensive and reliable glycosylated flavonoid profiling. This approach facilitates in-depth and simultaneous exploration of all detected precursors and fragments during data processing, employing the widely-used open-source MZmine 3 software. It was applied to a dataset of six Ocotea plant species. This framework suggested 49 flavonoids potentially newly described for these plant species, alongside 45 known features within the genus. Flavonols kaempferol and quercetin, both exhibiting O-glycosylation patterns, were particularly prevalent. Gas-phase fragmentation reactions further supported these findings. For the first time, the apigenin flavone backbone was also annotated in most of the examined Ocotea species. Apigenin derivatives were found mainly in the C-glycoside form, with O. porosa displaying the highest flavone : flavonol ratio. The approach also allowed an unprecedented detection of kaempferol and quercetin in O. porosa species, and it has underscored the untapped potential of LC-MS/DIA data for broad and reliable flavonoid profiling. Our study annotated more than 50 flavonoid backbones in each species, surpassing the current literature.

Comprehensive feature-based molecular networking and metabolomics approaches to reveal the differences components in Cinnamomum cassia and Cinnamomum verum

Cinnamon was been a widely used plant in medicinal and spices for a long time and has spread all over the world. However, the differences in the components of the bark from Cinnamomum cassia and Cinnamomum verum, the two most common types of cinnamon, have not been thoroughly investigated. In the present experiment, ultra-high-performance liquid chromatography LTQ-Orbitrap Velos Pro hybrid mass spectrometer-based metabolomics coupled with chemometrics and feature-based molecular networking were employed to dramatically distinguish and annotate Cinnamomum cassia Bark and Cinnamomum verum bark. As a consequence, principal component analysis, orthogonal projection to latent structures discriminates analysis, and heat map analysis demonstrated clear discrimination between the profiles of metabolites in cinnamon. Besides, as the known compounds, proanthocyanidins (cinnamtannin B1 and procyanidin B2) and alkaloids (norboldine, norisoboldine) with variable importance in the projection scores >6, and an unknown alkaloid (formula C₂₄ H₃₃ NO₆ ) were selected as the best markers to discriminate cinnamon. Furthermore, large numbers of proanthocyanidins and alkaloids components were identified through feature-based molecular networking for the first time. Our investigation provides new ideas for the discovery of quality markers and identification of unknown components in natural products.

Systematic Profiling of the Multicomponents and Authentication of Erzhi Pill by UHPLC/Q-Orbitrap-MS Oriented Rapid Polarity-Switching Data-Dependent Acquisition and Selective Monitoring of the Chemical Markers Deduced from Fingerprint Analysis

The analytical platform UHPLC/Q-Orbitrap-MS offers a solution to quality investigation of TCM with high definiteness. Using Erzhi Pill (EZP) as a case, we developed UHPLC/Q-Orbitrap-MS based approaches to achieve systematic multicomponent identification and rapid authentication. Comprehensive multicomponent characterization of EZP was performed by negative/positive switching data-dependent high-energy collision-induced dissociation-MS² (HCD-MS²) after 25 min chromatographic separation. By reference compounds comparison, elemental composition analysis, fragmentation pathways interpretation, and retrieval of an in-house library, 366 compounds were separated and detected from EZP, and 96 thereof were structurally characterized. The fingerprints of two component drugs (Ligustri Lucidi Fructus, LLF; Ecliptae Herba, EH) for EZP were analyzed under the same LC-MS condition by full scan in negative mode. In combination with currently available pharmacological reports, eight compounds were deduced as the ‘identity markers’ of EZP. Selective ion monitoring (SIM) of eight marker compounds was conducted to authenticate six batches of EZP samples. Both LLF and EH could be detected from all EZP samples by analyzing the SIM spectra, which could indicate their authenticity. Conclusively, UHPLC/Q-Orbitrap-MS by rapid polarity switching could greatly expand the potency of untargeted profiling with high efficiency, and SIM of multiple chemical markers rendered a practical approach enabling the authentication of TCM formulae.

Rapid Screening of Chemical Constituents in Rhizoma Anemarrhenae by UPLC-Q-TOF/MS Combined with Data Postprocessing Techniques

Rhizoma Anemarrhenae, a famous traditional Chinese medicine (TCM), is the dried rhizome of Anemarrhena asphodeloides Bge. (Anemarrhena Bunge of Liliaceae). The medicine presents anti-inflammatory, antipyretic, sedative, and diuretic effects. The chemical constituents of Rhizoma Anemarrhenae are complex and diverse, mainly including steroidal saponins, flavonoids, phenylpropanoids, benzophenones, and alkaloids. In this study, UPLC-Q-TOF/MS was used in combination with data postprocessing techniques, including characteristic fragments filter and neutral loss filter, to rapidly classify and identify the five types of substances in Rhizoma Anemarrhenae. On the basis of numerous literature reviews and according to the corresponding characteristic fragments produced by different types of compounds in combination with neutral loss filtering, we summarized the fragmentation patterns of the main five types of compounds and successfully screened and identified 32 chemical constituents in Rhizoma Anemarrhenae. The components included 18 steroidal saponins, 6 flavonoids, 4 phenylpropanoids, 2 alkaloids, and 2 benzophenones. The method established in this study provided necessary data for the study on the pharmacological effects of Rhizoma Anemarrhenae and also provided the basis for the chemical analysis and quality control of TCMs to promote the development of a method for chemical research on TCMs.