Time segment scanning-based quasi-multiple reaction monitoring mode by ultra-performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry for quantitative determination of herbal medicines: Moutan Cortex, a case study

Ultrasound-Assisted Extraction of Paeonol from Moutan Cortex: Purification and Component Identification of Extract

Moutan Cortex (MC) is a traditional Chinese medicine that contains abundant medicinal components, such as paeonol, paeoniflorin, etc. Paeonol is the main active component of MC. In this study, paeonol was extracted from MC through an ultrasound-assisted extraction process, which is based on single-factor experiments and response surface methodology (RSM). Subsequently, eight macroporous resins of different properties were used to purify paeonol from MC. The main components of the purified extract were identified by ultra-performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS/MS). The results indicate the optimal parameters are as follows: liquid-to-material ratio 21:1 mL/g, ethanol concentration 62%, ultrasonic time 31 min, ultrasonic temperature 36 °C, ultrasonic power 420 W. Under these extraction conditions, the actual yield of paeonol was 14.01 mg/g. Among the eight tested macroporous resins, HPD-300 macroporous resin was verified to possess the highest adsorption and desorption qualities. The content of paeonol increased from 6.93% (crude extract) to 41.40% (purified extract) after the HPD-300 macroporous resin treatment. A total of five major phenolic compounds and two principal monoterpene glycosides were characterized by comparison with reference compounds. These findings will make a contribution to the isolation and utilization of the active components from MC.

Targeted quantitative analysis of monoterpenoid indole alkaloids in Alstonia scholaris by ultra-high-performance liquid chromatography coupled with quadrupole time of flight mass spectrometry

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.

Chemical Profile Determination and Quantitative Analysis of Components in Oryeong-san Using UHPLC-Q-Orbitrap-MS and UPLC-TQ-MS/MS

In this study, a method to both qualitatively and quantitively analyze the components of Oryeong-san (ORS), which is composed of five herbal medicines (Alisma orientale Juzepzuk, Polyporus umbellatus Fries, Atractylodes japonica Koidzumi, Poria cocos Wolf, and Cinnamomum cassia Presl) and is prescribed in traditional Oriental medicine practices, was established for the first time. First, ORS components were profiled using ultra-high-performance liquid chromatography/quadrupole Orbitrap mass spectrometry, and 19 compounds were clearly identified via comparison against reference standard compounds. Subsequently, a quantitative method based on ultra-high-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry was established to simultaneously measure the identified compounds. Nineteen compounds were accurately quantified using the multiple-reaction-monitoring mode and used to analyze the sample; we confirmed that coumarin was the most abundant compound. The method was validated, achieving good linearity (R2 ≤ 0.9991), recovery (RSD, 0.11-3.15%), and precision (RSD, 0.35-9.44%). The results suggest that this method offers a strategy for accurately and effectively determining the components of ORS, and it can be used for quality assessment and management.

Exploring the nephrotoxicity of sulfur-containing derivatives in sulfur-fumigated Panacis Quinquefolii Radix based on chemical profiling and untargeted metabolomics

ETHNOPHARMACOLOGICAL RELEVANCE

Panacis Quinquefolii Radix (PQR) is often illegally sulfur fumigated to extend shelf life and improve appearance, but existing regulations of detecting SO₂ residues do not accurately identify desulfurized sulfur-fumigated PQR (SF-PQR). Although sulfur-containing derivatives (SCDs) have been reported in some sulfur-fumigated herbs, there is a lack of research on the generation mechanisms and toxicity of SCDs. Our previous study reported the nephrotoxicity of SF-PQR, and there is an urgent necessity to illuminate the mechanism of toxicity as well as its association with SCDs.

AIM OF THE STUDY

To investigate the transformation pattern of chemical components and SCDs in SF-PQR, and to disclose the linkage between SCDs and SF-PQR nephrotoxicity.

MATERIALS AND METHODS

The extracts of PQR (before and after SF) were detected by the UPLC-LTQ-Orbitrap-MS method, and SCDs were screened as quality markers (Q-markers). The composition of sulfur combustion products was examined by ion chromatography to exploit the conversion mechanism of SCDs. After administration of PQR extracts to mice for two weeks, serum was collected for GC-MS-based untargeted metabolomics study to mine for differential metabolites. The upstream genes were traced by network analysis to probe toxicity targets. Molecular docking was used to uncover the interactions between SCDs and the targets.

RESULTS

Thirty-three compounds were identified and 11 SCDs of saponins were screened, including four SO₃ sulfonation products and five H₂SO₃ sulfonation products. Metabolomics study showed significant alterations in serum biochemistry of SF-PQR group, with substantial increases in fumarate and 2-heptanone content, and induced disturbances in glycerolipid metabolism and phenylalanine, tyrosine, and tryptophan biosynthesis in mice. Network analysis revealed that the key toxicity targets were DECR1, PLA2G1B, and CAT. Molecular docking indicated that SCDs had stable interaction forces with the above three toxicity targets.

CONCLUSION

SF-PQR caused kidney damage by affecting glycerolipid metabolism and phenylalanine, tyrosine, and tryptophan biosynthesis. Eleven SCDs were potential nephrotoxic substances and Q-markers for identifying SF-PQR. This study is the first to systematically elucidate the mechanism of SF-PQR-related nephrotoxicity, providing a robust basis for the construction of new quality control standards and a global prohibition of sulfur fumigation.

Evaluations and Mechanistic Interrogation of Natural Products Isolated From Paeonia suffruticosa for the Treatment of Inflammatory Bowel Disease

Mu Dan Pi (MDP), a traditional Chinese medicine derived from the root bark of Paeonia suffruticosa Andrews, is used to treat autoimmune diseases due to its anti-inflammatory properties. However, the impact of MDP on inflammatory bowel disease (IBD) and its principal active compounds that contribute to the anti-inflammatory properties are uncertain. Thus, this study systemically evaluated the anti-inflammatory effects of fractionated MDP, which has therapeutic potential for IBD. MDP fractions were prepared by multistep fractionation, among which the ethyl acetate-fraction MDP5 exhibited the highest potency, with anti-inflammatory activity screened by the Toll-like receptor (TLR)-2 agonist, Pam3CSK4, in a cell-based model. MDP5 (at 50 μg/ml, p < 0.001) significantly inhibited nuclear factor kappa-B (NF-κB) reporters triggered by Pam3CSK4, without significant cell toxicity. Moreover, MDP5 (at 10 μg/ml) alleviated proinflammatory signaling triggered by Pam3CSK4 in a dose-dependent manner and reduced downstream IL-6 and TNF-α production (p < 0.001) in primary macrophages. MDP5 also mitigated weight loss, clinical inflammation, colonic infiltration of immune cells and cytokine production in a murine colitis model. Index compounds including paeoniflorin derivatives (ranging from 0.1 to 3.4%), gallic acid (1.8%), and 1,2,3,4,6-penta-O-galloyl-β-D-glucose (1.1%) in MDP5 fractions were identified by LC-MS/MS and could be used as anti-inflammatory markers for MDP preparation. Collectively, these data suggest that MDP5 is a promising treatment for IBD patients.

High-throughput screening of secondary metabolites by Sorbus pohuashanensis cells under environmental stress using UHPLC-QTOF combined with AntDAS

Environment stress can promote the synthesis and accumulation of a series of secondary metabolites, which are important quality factors in medicinal plants. However, the data related to metabolites is often too large, making it difficult to screen quickly, accurately and comprehensively various differential compounds. In this study, a high-throughput screening method for differential secondary metabolites produced by medicinal plants under environmental stress has been developed based on ultrahigh performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF) and automatic data analysis strategy. This work uses Sorbus pohuashanensis cells with biotic stress (Harpin protein) and abiotic stress (Cd²⁺ ) as potential environmental stress factors. The results showed that S. pohuashanensis cells could rapidly respond to both Harpin protein and Cd²⁺ within 24 h, and a significant positive correlation was observed between their concentration (within a certain range) and induction time. The proposed screening method can automatically screen the bulk UHPLC-QTOF metabolic data for differential compounds with high-throughput, and also perform preliminary identification of their possible structures. The screening results indicated that the stress response of S. pohuashanensis cells to Cd²⁺ was significantly higher than that of Harpin protein, and all of them could produce a series of biphenyls, terpenes, and other phytoalexins with stress-resistance and physiological functional properties. Overall, the screening method provides an efficient and powerful tool to study the response mechanisms of plants to environmental stress, to improve the resistance of medicinal plants and also to select and breed high-quality Chinese medicinal plants.

A multi-evaluating strategy for Weikangling capsules: Chemical profiling, fingerprinting combined with quantitative analysis, quantity transfer, and dissolution curve

Weikangling capsules (WKLCs), a Chinese patent medicine consisting of 8 Chinese drugs, have been widely used in clinic to treat gastrointestinal diseases for more than 30 years. The current "Chinese Pharmacopoeia" (2020 Edition, ChP2020) uses paeoniflorin content (≥ 1.0 mg per capsule) as the standard of quality control, but it is insufficient to evaluate the overall quality of WKLCs. An efficient and economic method for quality control is urgently needed to ensure the quality consistency and clinical effects of WKLCs. Herein, a systematic and reliable method for the rapid analysis of chemical components in WKLCs was established for the first time based on ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS). A total of 115 components covering 7 herbs in WKLCs were preliminarily identified by comparison with standard substances or literature. To evaluate the quality of 26 batches of WKLCs, a new method of fingerprinting combined with quantitative analysis was established, and 16 common peaks were selected to establish the fingerprint similarity model (similarity>0.90). Simultaneously, the contents of albiflorin, paeoniflorin, dactylorhin A, militarine, and glycyrrhizic acid were determined to be 0.82 ± 0.22, 2.09 ± 0.24, 1.15 ± 0.40, 3.73 ± 0.76 and 0.99 ± 0.20 mg/capsule, respectively. The transfer rates and dissolution curves of the five compounds were successfully detected in WKLCs, and the average transfer rates were 67.2%, 33.0%, 68.3%, 54.7%, and 33.7%, respectively. Notably, the dissolution profiles of different manufacturers presented remarkable differences in pH 1.2 hydrochloric acid solution. This method not only qualitatively identified the chemical components of Chinese patent medicines at the microlevel but also evaluated the quality consistency between batches at the macrolevel, which provided a comprehensive reference for the quality consistency of Chinese patent medicines between batches.

Mass Spectrometry-Based Metabolomics to Investigate the Effect of Mechanical Shaking on Sauvignon Blanc Berry Metabolism

Previous commercial studies carried out in New Zealand showed that mechanical shaking significantly reduced the incidence of Botrytis cinerea infection in wine grapes. However, the reasons behind this reduction are not well understood. Here, we employed a metabolomics approach to gain insights into the biochemical changes that occur in grape berries due to mechanical shaking. Berry samples were analyzed using three different analytical approaches including gas chromatography and mass spectrometry (MS), liquid chromatography and MS, and imaging mass spectrometry (IMS). Combined data provided a comprehensive overview of metabolic changes in grape berry, indicating the initiation of different stress mitigation strategies to overcome the effect of mechanical shaking. Berry primary metabolism was distinctly altered in the green berries in response to mechanical shaking, while secondary metabolism significantly changed in berries collected after veraison. Pathway analysis showed upregulation of metabolites related to nitrogen and lipid metabolism in the berries from shaken vines when compared with controls. From IMS data, we observed an accumulation of different groups of metabolites including phenolic compounds and amino and fatty acids in the areas near to the skin of berries from shaken vines. This observation suggests that mechanical shaking caused an accumulation of these metabolites, which may be associated with the formation of a protective barrier, leading to the reduction in B. cinerea infection in berries from mechanically shaken vines.

A systematic identification of anti-inflammatory active components derived from Mu Dan Pi and their applications in inflammatory bowel disease

Mu Dan Pi (MDP), also known as Moutan Cortex Radicis, is a traditional Chinese medicine used to treat autoimmune diseases. However, the impact of MDP and its principal active compounds on inflammatory bowel disease (IBD) is uncertain. This study therefore systemically assessed the anti-inflammatory effects of MDP and its known active compounds in IBD. The anti-inflammatory activities of water extract and individual compounds were screened by NF-κB and interferon regulatory factor (IRF) reporter assays in THP-1 cells induced with either Toll-like receptor or retinoic acid inducible gene I/melanoma differentiation-associated gene 5 activators and further verified in bone marrow-derived macrophages. MDP water extract significantly inhibited the activation of NF-κB and IRF reporters, downstream signaling pathways and the production of IL-6 and TNF-α, in a dose-dependent manner. Among 5 known active components identified from MDP (1,2,3,4,6-penta-O-galloyl-β-d-glucose [PGG], gallic acid, methyl gallate, paeoniflorin, and paeonol), PGG was the most efficient at inhibiting both reporters (with an IC₅₀ of 5–10 µM) and downregulating IL-6 and TNF-α. Both MDP powder for clinical use and MDP water extract, but not PGG, reduced colitis and pathological changes in mice. MDP and its water extract show promise as a novel therapy for IBD patients.

Four active monomers from Moutan Cortex exert inhibitory effects against oxidative stress by activating Nrf2/Keap1 signaling pathway

Paeonol, quercetin, β-sitosterol, and gallic acid extracted from Moutan Cortex had been reported to possess anti-oxidative, anti-inflammatory, and antitumor activities. This work aimed to illustrate the potential anti-oxidative mechanism of monomers in human liver hepatocellular carcinoma (HepG2) cells-induced by hydrogen peroxide (H2O2) and to evaluate whether the hepatoprotective effect of monomers was independence or synergy in mice stimulated by carbon tetrachloride (CCl4). Monomers protected against oxidative stress in HepG2 cells in a doseresponse manner by inhibiting the generation of reactive oxygen species, increasing total antioxidant capacity, catalase and superoxide dismutase (SOD) activities, and activating the antioxidative pathway of nuclear factor E2-related factor 2/Kelchlike ECH-associated protein 1 (Nrf2/Keap1) signaling pathway. We found that the in vitro antioxidant capacities of paeonol and quercetin were better than those of β-sitosterol and gallic acid. Furthermore, paeonol apparently diminished the levels of alanine transaminase and aspartate aminotransferase, augmented the contents of glutathione and SOD, promoted the expressions of Nrf2 and heme oxygenase-1 proteins in mice stimulated by CCl4. In HepG2 cells, paeonol, quercetin, β-sitosterol, and gallic acid play a defensive role against H2O2-induced oxidative stress through activating Nrf2/Keap1 pathway, indicating that these monomers have anti-oxidative properties. Totally, paeonol and quercetin exerted anti-oxidative and hepatoprotective effects, which is independent rather than synergy.

Effects of chromatographic conditions and mass spectrometric parameters on the ionization and fragmentation of triterpene saponins of Ilex asprella in liquid chromatography-mass spectrometry analysis

High performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (HPLC-QTOF-MS) is widely used to qualitatively characterize the chemical profiles of herbal medicines, in which the generated adducts and fragments are crucial for confirming molecular ion (deprotonated/protonated ion) and deducing structure of detected components. However, how chromatographic and mass spectrometric (LC-MS) conditions/parameters affect the quantity and intensity of adducts and fragments of detected components is scarcely concerned. In present study, three types of triterpene saponins from the root of Ilex asprella (RIA) were selected as a case study to systematically investigate the effects of LC/MS conditions/parameters on their ionization and fragmentation, so as to obtain higher intensity (higher detection sensitivity) and quantity (rich information) of adducts and fragments for the characterization of components in RIA. It was found that for LC conditions, methanol as organic phase was more benefit for generating more adducts with higher intensity; formic acid as a modifier suppressed the formation of [M-2H]^2-, thus promoted the generation of other types of adducts at lower concentration but inhibited the generation when the concentration exceeded 0.1%. MS parameters affect scarcely the quantity but mainly intensity of adducts, cone voltage, source temperature and desolvation gas flow have relatively higher impacts when compared with other parameters. Collision energy affected both quantity and intensity of fragments. MS parameters at the medium value largely increased the quantity and intensity of adducts and fragments. Three-types of triterpene saponins presented structurally specific ionization and fragmentation due to their amounts of acidic substitutes. A total of 55 components were detected and definitely or tentatively identified in RIA under the optimized LC-MS conditions, among which 35 triterpene saponins were firstly discovered. This is the first report that proposes and validates a systematic approach for assessing the effects of LC/MS conditions/parameters on the ionization and fragmentation of analytes, which could be helpful for the optimization of LC-MS conditions for effective chemical profiling analysis of herbal medicines.