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Monoterpene indole alkaloids exhibit structural diversity in herbal resources and have been developed as promising drugs owing to their significant biological activities. Confidential identification and quantification of monoterpene indole alkaloids is the key to quality control of target plants in industrial production but has rarely been reported. In this study, quantitative performance of three data acquisition modes of ultra‐high‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry including full scan, auto‐MS2 and target‐MS2, was evaluated and compared for specificity, sensitivity, linearity, precision, accuracy, and matrix effect using five monoterpene indole alkaloids (scholaricine, 19‐epi‐scholaricine, vallesamine, picrinine, and picralinal). Method validations indicated that target‐MS2 mode showed predominant performance for simultaneous annotation and quantification of analytes, and was then applied to determine monoterpene indole alkaloids in Alstonia scholaris (leaves, barks) after extraction procedures optimization using Box‐Behnken design of response surface methodology. The variations of A. scholaris monoterpene indole alkaloids in different plant parts, harvest periods, and post‐handling processes, were subsequently investigated. The results indicated that target‐MS2 mode could improve the quantitative capability of ultra‐high‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry for structure‐complex monoterpene indole alkaloids in herbal matrices. Alstonia scholaris, monoterpene indole alkaloids, quadrupole time of flight mass spectrometry, qualitative and quantitative analysis, ultra‐high‐performance liquid chromatography [ABSTRACT FROM AUTHOR]

Introduction: The structural annotation of target relies on high‐resolution mass spectrometry (HRMS) information resulting in dubious identities in most cases. The accurate annotation of isomeric structures is still challenging to be confirmed with significant bottleneck. Objective: This study focused on the improvement of structural annotation of candidate structures via four pairs of isomeric flavanone‐7‐O‐diglucosides and their basic flavanone aglycones commonly detected in citrus products. Method: An integrated liquid chromatography coupled with high‐resolution mass spectrometry (LC–HRMS) approach merging retention time, accurate mass, tandem mass spectrometry (MS/MS) information (diagnostic ions), ion ratio at selected collision energy was established successfully. R esults : Feasibility of this approach was validated confidently in biological samples with relative standard deviation (RSD) of ion ratio range from 3.91 to 12.28%. Differences of fragmentation patterns of citrus flavanones were illustrated reasonably. MS/MS fragments of (S)‐hesperetin and (S)‐isosakuranetin were complicated and showed typical radical ion [1,2A – H]•– (m/z 164) in negative ESI mode due to the methoxyl group on B‐ring, which showed huge difference with (R)‐hesperetin and (R)‐isosakuranetin. Conclusion: This study integrated multiple levels to boost the confidence of structural annotation relied on LC–HRMS, and provided important values in practice for precise identification of citrus flavanones in biological matrices. An integrated method (RT‐AM‐MS/MS‐IR) relied on LC‐HRMS to promote the confidence of structural annotation was established and validated via isomeric citrus flavanones in biosamples. And this method was applied successfully to distinguish the enantiomers of flavanone aglycones that usually possess (R)‐ and (S)‐enantiomers in vivo including naringenin, hesperetin and isosakuranetin. [ABSTRACT FROM AUTHOR]

Ethnopharmacological Relevance: Caryopteris trichosphaera W. W. Sm., a traditional ethnic medicine, was recorded in the Compendium of Materia Medica for treating wound infection by pathogenic infection. However, its antibacterial potential and bioactive compositions against drug-resistant bacteria need to be validated., Aim of the Study: To investigate the chemical constituents of C. trichosphaera and explore its anti-MRSA component in vitro and in vivo, together with the antibacterial mechanism., Materials and Methods: Bioactive constituents investigation was carried out by phytochemical method and antibacterial screening. The antibacterial mechanism was predicted by network pharmacology, which was further validated by time-kill analysis, membrane function tests, multigenerational resistance induction assay and biofilm test, and metabolomics analysis in vitro. In addition, MRSA-induced epidermal infection in mice was selected to evaluate its pharmacological effect in vivo., Results: Six antibacterial diterpenoids against MRSA and VRE with MIC values 4-32 μg/mL from C. trichosphaera were reported for the first time, in which the major compound cativic acid (1) disrupted MRSA cell membranes by modulating permeability, depolarization, and fluidity while increasing reactive oxygen species (ROS) and malondialdehyde (MDA) levels. It also displayed remarkable anti-biofilm activity without inducing bacterial resistance or cytotoxicity. Moreover, cativic acid affected MRSA biosynthesis of cofactors, amino acid biosynthesis, nucleotide metabolism by metabolomics analysis. Furthermore, cativic acid accelerated wound healing in MRSA-infected mouse skin wounds, even better than vancomycin., Conclusions: The results supported the traditional use of C. trichosphaera, and presented unreported anti-MRSA agent, cativic acid, as a plant-derived bactericide in vitro and in vivo for the first time., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Zanthoxylum motuoense (Tibetan prickly ash, MTHJ), different from the Chinese prickly ash species, is distributed only in the Tibet. Now the chemical characterization and antibacterial activity of MTHJ extracts were analyzed for the first time. As a result, Schinifoline (12) , γ -Fagarine (8) , ( 2E,7E,9E )-6 S-Hydroxy- N -(2-methylpropyl)-11-oxo-2, 7, 9-Dodecatrienamide (6) , and Neoechinulin A (17) were found to be the major different factors by untarget LC-MS metabolomics together with quantitative analysis on target. These four compounds were also the major antibacterial constituents. Then, the antimicrobial activity of MTHJ fractions was evaluated with colony forming units (CFU), fluorescence microscopy imaging, SEM and investigating the potential food preservation. Nutritional composition, colour and sensory evaluation of extract-treated samples were evaluated along storage time. The results suggested the MTHJ may be used for meat products preservation, and the scores were significantly higher for its unique flavor, which offered a promising choice for food safety, preservation and reducing foodborne illness., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors. Published by Elsevier Ltd.)