A quantitative chemomics strategy for the comprehensive comparison of Murraya paniculata and M. exotica using liquid chromatography coupled with mass spectrometry

Murrayae Folium et Cacumen (MFC) is a traditional Chinese medicine (TCM) derived from two plant species, Murraya exotica L. and Murraya paniculata (L.) Jack, as recorded in the Chinese Pharmacopoeia. However, there is no research available on the comprehensive analysis and comparison of the chemical constituents of these two species. In the present study, an integrated LC-MS-based quantitative metabolome strategy was proposed to conduct a comprehensive and in-depth qualitative and quantitative analysis and comparison of the chemome of M. exotica and M. paniculata. Firstly, the universal chemical information of two plants was obtained by quadrupole-time-of-flight mass spectrometry (Q-TOF-MS) combined with hybrid triple quadrupole-linear ion trap mass spectrometry (Qtrap-MS). Subsequently, a UNIFI in house database, the proposed fragmentation patterns, and a quantitative structure chromatographic retention relationship (QSRR) model were integrated for the rapid, comprehensive, and accurate structural elucidation of the chemical constituents of these two species. Thirdly, a large-scale quantitation method was established using scheduled multiple reaction monitoring mode (sMRM) and 76 primary components were selected as quantitative markers for the method validation. The obtained dataset was then subjected for multivariate statistical analysis to comprehensive comparison of these two plants. As a result, a total of 209 and 212 compounds were identified from M. exotica and M. paniculata, respectively. Among them, 103 common constituents were disclosed in both plants. The multivariate statistical analysis and absolute quantitative analysis revealed noticeable differences in the contents of specific chemical constituents between these two plants. The higher quantity constituents in M. exotica are 7-methoxycoumarins, while polymethoxylated flavonoids are the major constituents in M. paniculata. The common compounds accounted for approximately 80 % of the quantitative components in both plants, which provides a theoretical basis for their common use as the official source of MFC. In sum, the established quantitative chemomics strategy supplies an effective means for comprehensive chemical comparison of multi-source TCMs.

Investigation of the metabolites of five major constituents from Berberis amurensis in normal and pseudo germ-free rats

Berberis amurensis (Berberidaceae) is a traditional Chinese medicine, which is often used to treat hypertension, inflammation, dysentery and enteritis. It contains alkaloids, mainly including berberine, berbamine, magnoflorine, jatrorrhizine and palmatine. Berberis amurensis extracts (BAEs) is often orally taken. Oral herbs might be metabolized by intestinal bacteria in the small intestine. However, the interaction between the herb and the gut microbiota is still unknown. In the current study, UPLC/Q-TOF-MS/MS combined with Metabolitepilot and Peakview software was used to identify the metabolites of BAEs in anti-biotic cocktail induced pseudo germ-free rats and normal rats. As a result, a total of 46 metabolites in normal rats were detected and its main metabolic pathways include demethylation, dehydrogenation, methylation, hydroxylation, sulfation and glucuronidation. Only 29 metabolites existed in pseudo germ-free rats. Dehydrogenated metabolites (M29, M30, M34 and M36), methylated metabolites (M33, M41 and M46) and other metabolites were not detected in pseudo germ-free rats. The result implied that the intestinal bacteria have an influence on the metabolism of BAEs. Furthermore, this investigation might contribute to the understanding of the metabolism of BAEs, and further promote its clinical application.

Evaluation of the effects of notoginseng total saponins (NS), safflower total flavonoids (SF), and the combination of NS and SF (CNS) on the activities of cytochrome P450 enzymes using a cocktail method in rats

Notoginseng total saponins (NS), safflower total flavonoids (SF), and the combination of NS and SF, namely CNS, are used for the treatment of cardiovascular diseases in clinic. This study developed a cocktail assay involving seven cytochrome P450 (CYP) enzymes to elucidate the effect of NS, SF, and CNS on CYP enzymes and to explore the synergistic effect of CNS in terms of CYP enzymes. Ultra-performance liquid chromatography-MS and reverse-transcription polymerase chain reaction were applied to detect the activities and mRNA expression levels of CYP enzymes. SF exhibited inhibitory effects on CYP1A2, 2B1, 2E1, and 2C11 and induction effects on CYP2C19 and 2D4. NS exhibited induction effects on CYP1A2, 2B1, 2E1, 2C11, 2C19, and 2D4. CNS exhibited induction effects on CYP1A2, 2B1, 2E1, 2C19, and 2D4 and inhibitory effects on CYP3A1 in vivo. Moreover, mRNA expression results were consistent with pharmacokinetic results. Potential herb-drug interactions should be studied closely when SF, NS, or CNS with clinical drugs are metabolized by CYP1A2, 2B1, 2E1, 2C11, 2C19, 2D4, and 3A1. CNS could change the inhibition or induction effects of CYP compared to the NS group, which might be one of the causes for the synergistic effects of the combination of NS and SF.

Comprehensive metabolic profiling of Alismatis Rhizoma triterpenes in rats based on characteristic ions and a triterpene database

Alismatis Rhizoma (AR) is widely used in Chinese medicine, and its major bioactive components, triterpenes, reportedly possess various pharmacological activities. Therefore, it is very important to study the metabolism of triterpenes in vivo. However, the metabolism of AR triterpene extract has not been comprehensively elucidated due to its complex chemical components and metabolic pathways. In this study, an ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry method, which was based on the characteristic ions from an established database of known triterpenes, was used to analyze the major metabolites in rats following the oral administration of Alismatis Rhizoma extracts (ARE). As a result, a total of 233 constituents, with 85 prototype compounds and 148 metabolites, were identified for the first time. Hydrogenation, oxidation, sulfate and glucuronidation conjugation were the major metabolic pathways for triterpenes in AR. In addition, the mutual in vivo transformation of known ARE triterpenes was discovered and confirmed for the first time. Those results provide comprehensive insights into the metabolism of AR in vivo, which will be useful for future studies on its pharmacodynamics and pharmacokinetics. Moreover, this established strategy may be useful in metabolic studies of similar compounds.

Greener extraction process and enhanced in vivo bioavailability of bioactive components from Carthamus tinctorius L. by natural deep eutectic solvents

Natural deep eutectic solvents (NaDESs) are promising green alternatives to conventional solvents widely applied in the extraction of natural products due to their physical and chemical superiorities. In present study, 22 NaDESs consisted from food grade ingredients were screened in ultrasonic assisted extraction (UAE) of bioactive compounds from safflower. The oral bioavailabilities of hydroxysafflor yellow A (HSYA) and anhydrosafflor yellow B (ASYB) in the extracts were then investigated in SD rats with the help of HPLC-MS technique. The results revealed that l-proline-acetamide (l-Pro-Am) was an effective solvent with the yields of HSYA and ASYB at 32.83 and 8.80 mg/g. Pharmacokinetic studies revealed that the blood level of HSYA and ASYB were significantly higher after oral administration of l-Pro-Am extract than that of aqueous extract. Especially, the relative bioavailabilities (to aqueous extract) of HSYA and ASYB were calculated 183.5% and 429.8%.

Large Volume Direct Injection Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry-Based Comparative Pharmacokinetic Study between Single and Combinatory Uses of Carthamus tinctorius Extract and Notoginseng Total Saponins

The combination of Carthamus tinctorius extract (CTE) and notoginseng total saponins (NGTS), namely, CNP, presents a synergistic effect on myocardial ischemia protection. Herein, comparative pharmacokinetic studies between CNP and CTE/NGTS were conducted to clarify their synergistic mechanisms. A large volume direct injection ultra-high performance liquid chromatography-tandem mass spectrometry (LVDI-UHPLC-MS/MS) platform was developed for sensitively assaying the multi-component pharmacokinetic and in vitro cocktail assay of cytochrome p450 (CYP450) before and after compatibility of CTE and NGTS. The pharmacokinetic profiles of six predominantly efficacious components of CNP, including hydroxysafflor yellow A (HSYA); ginsenosides Rg₁ (GRg₁), Re (GRe), Rb₁ (GRb₁), and Rd (GRd); and notoginsenoside R₁ (NGR₁), were obtained, and the results disclosed that CNP could increase the exposure levels of HSYA, GRg₁, GRe, GRb₁, and NGR₁ at varying degrees. The in vitro cocktail assay demonstrated that CNP exhibited more potent inhibition on CYP1A2 than CTE and NGTS, and GRg₁, GRb₁, GRd, quercetin, kaempferol, and 6-hydroxykaempferol were found to be the major inhibitory compounds. The developed pharmacokinetic interaction-based strategy provides a viable orientation for the compatibility investigation of herb medicines.

Comparative study on metabolic profiling and excretion in rat bile between combination of notoginseng total saponins and safflower total flavonoids and its individual extracts by LC-MS/MS

The combination of notoginseng total saponins (NS) and safflower total flavonoids (SF), namely CNS, presents a synergistic protection effect on the myocardial ischemia rats. The aim of this study was to find the clues for their synergistic actions by comparing the biliary metabolism and excretion profiles after oral administration of CNS and its individual extracts. An ultra-performance liquid chromatography coupled with hybrid triple quadrupole-linear ion trap mass spectrometer (UPLC-QTRAP-MS/MS) platform was used to identify and quantify the CNS-derived components in bile. The neutral losses, precursor ions, and predictive multiple reaction monitoring (pMRM) scans were firstly used to detect the CNS-derived ingredients in vivo. A total of 43 components, including 38 flavonoids and 5 ginsenosides were tentatively identified according to the previously established chemical and metabolic profiles of NS and SF. Afterwards, the primary circulating and biological components, hydroxysafflor yellow A (HSYA), ginsenosides Rg₁ (GRg₁), Re (GRe), and Rd (GRd) were chosen to compare the bile excretion between CNS and its individual extract groups, by using a validated LC-MRM-MS/MS method. The approach was proved to be well satisfied the related requirements from the guidelines of FDA (specificity, calibration curve, sensitivity, precision, accuracy, matrix effect, recovery, and stability). Comparing with the SF and NS groups, the combination group did not affect the metabolic pathways of the CNS-related components, however, it decreased the cumulative excretion ratios of HSYA, GRg₁, GRe, and GRd. In conclusion, the compatibility of SF and NS could reduce the bile excretion of the CNS-derived compounds, which may be one of the reasons for the enhancement of anti-myocardial ischemia after combination.

An integrated strategy based on characteristic fragment filter supplemented by multivariate statistical analysis in multi-stage mass spectrometry chromatograms for the large-scale detection and identification of natural plant-derived components in rat: The rhubarb case

An integrated strategy based on characteristic fragment filter (CFF) supplemented by multivariate statistical analysis (MSA) for MSⁿ chromatograms [(CFF)s MSA] was proposed for the large-scale detection of natural plant-derived ingredients in vivo. To prove the practicability of this [(CFF)s MSA] strategy, rhubarb was taken as an example. First, representative authentic standards of homologous components contained in rhubarb were chosen, from which the fragmentation rules and chemical characteristic fragments (CCFs) were proposed. Second, the metabolic pathways of the representative compounds were deciphered, and the metabolic characteristic fragments (MCFs) of each family of compounds were acquired. Third, combined with CCFs and MCFs, a CFF method was established. Finally, MSA was used to supplement the xenobiotics missed by the CFF method. In our research, 274 compounds were detected in rhubarb, and 298 ingredients were identified in vivo after oral administration. The results demonstrated that this integrated strategy could comprehensively screen for plant-derived compounds in vivo.

Polyphenolic Characterization, Antioxidant, and Cytotoxic Activities of Mangifera indica Cultivars from Costa Rica

The phenolic profile of skin and flesh from Manifera indica main commercial cultivars (Keitt and Tommy Atkins) in Costa Rica was studied using ultra performance liquid chromatography coupled with high resolution mass spectrometry (UPLC-ESI-MS) on enriched phenolic extracts. A total of 71 different compounds were identified, including 32 gallates and gallotannins (of different polymerization degree, from galloyl hexose monomer up to decagalloyl hexoses and undecagalloyl hexoses); seven hydroxybenzophenone (maclurin and iriflophenone) derivatives, six xanthonoids (including isomangiferin and mangiferin derivatives); 11 phenolic acids (hydroxybenzoic and hydroxycinnamic acid derivatives); and eight flavonoids (rhamnetin and quercetin derivatives). The findings for T. Atkins skin constitute the first report of such a high number and diversity of compounds. Also, it is the first time that the presence of gallotannin decamers and undecamers are reported in the skin and flesh of Keitt cultivar and in T. Atkins skins. In addition, total phenolic content (TPC) was measured with high values especially for fruits' skins, with a TPC of 698.65 and 644.17 mg gallic acid equivalents/g extract, respectively, for Keitt and T. Atkins cultivars. Antioxidant potential using 2,2-diphenyl-1-picrylhidrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) methods were evaluated, with T. Atkins skin showing the best values for both DPPH (IC₅₀ = 9.97 µg/mL) and ORAC (11.02 mmol TE/g extract). A significant negative correlation was found for samples between TPC and DPPH antioxidant values (r = -0.960, p < 0.05), as well as a significant positive correlation between TPC and ORAC (r = 0.910, p < 0.05) and between DPPH and ORAC antioxidant methods (r = 0.989, p < 0.05). Also, cytotoxicity was evaluated in gastric adenocarcinoma (AGS), hepatocarcinoma (HepG2), and colon adenocarcinoma (SW620), with T. Atkins skin showing the best results (IC₅₀ = 138-175 µg/mL). Finally, for AGS and SW 620 cell lines particularly, a high significant negative correlation was found between cytotoxic activity and gallotannins (r = -0.977 and r = -0.940, respectively) while for the HepG2 cell line, the highest significant negative correlation was found with xanthonoids compounds (r = -0.921).

Rapid quantitation and identification of the chemical constituents in Danhong Injection by liquid chromatography coupled with orbitrap mass spectrometry

Danhong Injection (DHI) is a Chinese medicine patent drug to treat cardiovascular diseases. It is derived from the herbal medicines Dan-shen and Hong-hua. The bioactive compounds of DHI are polar phenolic acids and flavonoid glycosides. Thus far, the contents of major compounds in DHI are not well understood, and the identification of minor compounds lacks rapid methods. In this work, quantitative and qualitative analyses of DHI compounds were performed using ultra-high performance liquid chromatography coupled with orbitrap mass spectrometry (UHPLC/orbitrap-MS). DHI was separated on an Acquity HSS T3 column (1.8 μm, 100 mm × 2.1 mm) and eluted with acetonitrile-water (containing 0.1% formic acid) to determine the contents of 12 compounds within 6 min. The method was fully validated according to the ICH guidance. To identify the minor compounds, an ion statistics-based strategy was used to dig for 4 filtering ions and 6 diagnostic ions from 22 reference standards. A total of 117 compounds, including 76 phenolic acids, 20 flavonoids, and 21 other compounds were tentatively identified. The poor stability of salvianolic acid A upon storage was also discussed.

Comparative Study on Excretive Characterization of Main Components in Herb Pair Notoginseng-Safflower and Single Herbs by LC⁻MS/MS

The herbal medicine combination of notoginseng-safflower has been commonly used clinically for the prevention and treatment of cardiovascular diseases. A reliable liquid chromatography-tandem mass spectrometry (LC–MS/MS) method was developed for simultaneous determination of six bioactive components (hydroxysafflor yellow A, notoginsenoide R1, ginsenoside Rb1, Re, Rd, and Rg1) in rat urine and feces after oral administration of notoginseng total saponins (NS), safflower total flavonoids (SF), and the combination of NS and SF (CNS). The chromatographic separation was achieved on a Waters HSS T3 column under gradient elution with acetonitrile and water containing formic acid as the mobile phase. The calibration curves were linear, with correlation coefficient (r) > 0.99 for six components. The intra- and interday precision (RSD) and accuracy (RE) of QC samples were within −14.9% and 14.9%, respectively. The method was successfully applied to study of the urinary and fecal excretion of six bioactive constituents following oral administration of NS, SF, and CNS in rats. Compared to the single herb, the cumulative excretion ratios of six constituents were decreased in the herbal combination. The study indicated that the combination of notoginseng and safflower could reduce the renal and fecal excretion of the major bioactive constituents and promote their absorption in rats.

Protective effects of dietary kaempferol glycoside components from unripe soybean (Edamame, Glycine max L. Merrill. 'Jindai') leaves and their serous metabolite on carbon tetrachloride-induced liver injury mice

The study investigated the protective effects of kaempferol galactoside (KG) components in mice, which were separated from Jindai soybean leaves (JDL) and mainly composed by two kaempferol galactosides. Further, KG-related metabolites in serum of mice were identified by Tof-MS. Results showed that both JDL and KG prevented the CCl₄-induced increases in serum aspartate aminotransferase and serum alanine aminotransferase. Additionally, mice treated with KG had significantly decreased TBARS and TNF-alpha levels, compared to CCl₄-treated mice. Serous analysis showed that kaempferol, glucuronidated kaempferol and methylated kaempferol with a glucuronic acid moiety were identified in the serum of mice fed unripe soybean leaves or kaempferol galactosides isolated from the leaves. The results indicated that kaempferol 3-O-galactoside connected to other glycosides via galactose might be hydrolyzed in the gastro-intestinal tract and/or epithelium cells to release kaempferol, followed by glucuronidation and/or methylation in the liver to contribute to a reduction in liver injury. The use of raw leaves containing kaempferol galactosides as food materials may contribute to a reduction in oxidation-related diseases.

A Comprehensive Screening and Identification of Genistin Metabolites in Rats Based on Multiple Metabolite Templates Combined with UHPLC-HRMS Analysis

Genistin, an isoflavone belonging to the phytoestrogen family, has been reported to possess various therapeutic effects. In the present study, the genistin metabolites in rats were investigated by UHPLC-LTQ-Orbitrap mass spectrometer in both positive and negative ion modes. Firstly, the data sets were obtained based on data-dependent acquisition method and then 10 metabolite templates were established based on the previous reports. Then diagnostic product ions (DPIs) and neutral loss fragments (NLFs) were proposed to efficiently screen and ascertain the major-to-trace genistin metabolites. Meanwhile, the calculated Clog P values were used to identify the positional isomers with different retention times. Consequently, a total of 64 metabolites, including prototype drug, were positively or putatively characterized. Among them, 40 metabolites were found according to the templates of genistin and genistein, which was the same as the previous research method. After using other metabolite templates, 24 metabolites were added. The results demonstrated that genistin mainly underwent methylation, hydrogenation, hydroxylation, glucosylation, glucuronidation, sulfonation, acetylation, ring-cleavage and their composite reactions in vivo biotransformation. In conclusion, the research not only revealed the genistein metabolites and metabolic pathways in vivo comprehensively, but also proposed a method based on multiple metabolite templates to screen and identify metabolites of other natural compounds.

Integration of Metabolomics With Pharmacodynamics to Elucidate the Anti-myocardial Ischemia Effects of Combination of Notoginseng Total Saponins and Safflower Total Flavonoids

Notoginseng (Sanqi), the roots and rhizomes of Panax notoginseng and safflower, the flowers of Carthamus tinctorius, are widely used traditional Chinese medicines (TCMs) for the treatment of cardiovascular diseases. Positive evidences have fueled growing acceptance for cardioprotective effects of the combination of the notoginseng total saponins and safflower total flavonoids (CNS) against myocardial ischemia (MI). However, the underlying cardioprotective mechanisms of CNS are still obscured. Metabolomics is a comprehensive tool for investigating biological mechanisms of disease, monitoring therapeutic outcomes, and advancing drug discovery and development. Herein, we investigated the cardioprotective effects of CNS on the isoproterenol (ISO)-induced MI rats by using plasma and urine metabolomics based on ultra-performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UPLC-Q-TOF/MS) and multiple pharmacodynamics approaches. The results showed that pretreatment with CNS could attenuate the cardiac injury resulting from ISO, as evidenced by decreasing the myocardial infarct size, converting the echocardiographic, histopathological, and plasma biochemical abnormalities, and reversing the perturbations of plasma and urine metabolic profiles, particularly for the 55.0 mg/kg dosage group. In addition, 44 metabolites were identified as the potential MI biomarkers, mainly including a range of free fatty acids (FFAs), sphingolipids, and glycerophospholipids. CNS pretreatment group may robustly ameliorate these potential MI-related biomarkers. The accumulation of LysoPCs and FFAs, caused by PLA₂, may activate NF-κB pathway and increase proinflammatory cytokines. However, our results showed that CNS at 55.0 mg/kg dosage could maximally attenuate the NF-κB signaling pathway, depress the expressions of TNF-α, IL-6, IL-1β, and PLA₂. The results suggested that the anti-inflammatory property of CNS may contribute to its cardioprotection against MI. Our results demonstrate that the integrating of metabolomics with pharmacodynamics provides a reasonable approach for understanding the therapeutic effects of TCMs and CNS provide a potential candidate for prevention and treatment of MI.

A targeted strategy to identify untargeted metabolites from in vitro to in vivo: Rapid and sensitive metabolites profiling of licorice in rats using ultra-high performance liquid chromatography coupled with triple quadrupole-linear ion trap mass spectrometry

It is challenging to conduct in vivo metabolic study for traditional Chinese medicines (TCMs) because of complex components, unpredictable metabolic pathways and low metabolite concentrations. Herein, we proposed a sensitive strategy to characterize TCM metabolites in vivo at an orally clinical dose using ultra-high performance liquid chromatography-triple quadrupole-linear ion trap mass spectrometry (UHPLC-QTRAP-MS). Firstly, the metabolism of individual compounds in rat liver microsomes was studied to obtain the metabolic pathways and fragmentation patterns. The untargeted metabolites in vitro were detected by multiple ion monitoring-enhanced product ion (EPI) and neutral loss-EPI scans. Subsequently, a sensitive multiple reaction monitoring-EPI method was developed according to the in vitro results and predicted metabolites to profile the in vivo metabolites. Licorice as a model herb was used to evaluate and validate our strategy. A clinical dose of licorice water extract was orally administered to rats, then a total of 45 metabolites in urine, 21 metabolites in feces and 35 metabolites in plasma were detected. Among them, 18 minor metabolites have not been reported previously and 6 minor metabolites were first detected in vivo. Several isomeric metabolites were well separated and differentiated in our strategy. These results suggested that this new strategy could be widely used for the detection and characterization of in vivo metabolites of TCMs.

A comprehensive in vitro and in vivo metabolism study of hydroxysafflor yellow A

As the most important marker component in Carthamus tinctorius L., hydroxysafflor yellow A (HSYA) was widely used in the prevention and treatment of cardiovascular diseases, due to its effect of improving blood supply, suppressing oxidative stress, and protecting against ischemia/reperfusion. In this paper, both an in vitro microsomal incubation and an in vivo animal experiment were conducted, along with an LC-Q-TOF/MS instrument and a 3-step protocol, to further explore the metabolism of HSYA. As a result, a total of 10 metabolites were searched and tentatively identified in plasma, urine, and feces after intravenous administration of HSYA to male rats, although no obvious biotransformation was found in the simulated rat liver microsomal system. The metabolites detected involving both phase I and phase II metabolism including dehydration, deglycosylation, methylation, and glucuronic acid conjugation. A few of the metabolites underwent more than one-step metabolic reactions, and some have not been reported before. The study would contribute to a further understanding of the metabolism of HSYA and provide scientific evidence for its pharmacodynamic mechanism research and clinical use.

Identification of metabolites of liquiritin in rats by UHPLC-Q-TOF-MS/MS: metabolic profiling and pathway comparisonin vitroandin vivo

Liquiritin (LQ), the main bioactive constituent of licorice, is a common flavoring and sweetening agent in food products and has a wide range of pharmacological properties, including antidepressant-like, neuroprotective, anti-cancer and anti-inflammatory properties. This study investigated the metabolic pathways of LQ in vitro (rat liver microsomes) and in vivo (rat model) using ultra high-performance liquid chromatography coupled with hybrid triple quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS). Moreover, supplementary tools such as key product ions (KPIs) were employed to search for and identify compounds. As a result, 56 in vivo metabolites and 15 in vitro metabolites were structurally characterized. Oxidation, reduction, hydrolysis, methylation, acetylation, and sulfate and glucuronide conjugation were determined to be the major metabolic pathways of LQ, and there were differences in LQ metabolism in vitro and in vivo. In addition, the in vitro and in vivo metabolic pathways were compared in this study.

Liquiritin (LQ), the main bioactive constituent of licorice, is a common flavoring and sweetening agent in food products and has a wide range of pharmacological properties, including antidepressant-like, neuroprotective and anti-cancer properties.

An integrated strategy for rapid discovery and identification of the sequential piperine metabolites in rats using ultra high-performance liquid chromatography/high resolution mass spectrometery

Piperine, one of the major bioactive constituents isolated from natural flavorings and medicinal-culinary herbs, possesses various biological activities. In the present study, an integrated strategy based on ultra high-performance liquid chromatography/high resolution mass spectrometry was established to reveal piperine metabolism in rats. First of all, post-acquisition data-mining methods, including high resolution extracted ion chromatograms (HREICs) and multiple mass defect filtering (MMDF), were used to screen piperine metabolite candidates in a full-scan HRMS¹ level. Then, parent ion list-dynamic exclusion coupled with data-dependent data-acquisition method was utilized to acquire MSⁿ datasets. In addition, the established reverse molecular assembly (RMA) approach based on paired diagnostic product ions (pDPIs) coupled with neutral loss fragments (NLFs) was used to ascertain and identify the major-to-trace piperine metabolites efficiently. And then, the calculated ClogP values were utilized to distinguish the positional isomers. As a result, a total of 148 piperine metabolites were detected and characterized tentatively. The results demonstrated that piperine mainly underwent hydrogenation, dehydrogenation, hydroxylation, glucuronide conjugation, sulfate conjugation, ring-cleavage, and their composite reactions. Our results not only provided novel and useful data to better understand the safety, toxicity and efficacy of this potential therapeutic agent, but also indicated that the proposed strategy was reliable for a rapid discovery and identification drug-related constituents in vivo.

An enhanced targeted identification strategy for the selective identification of flavonoid O-glycosides from Carthamus tinctorius by integrating offline two-dimensional liquid chromatography/linear ion-trap-Orbitrap mass spectrometry, high-resolution diagnostic product ions/neutral loss filtering and liquid chromatography-solid phase extraction-nuclear magnetic resonance

Targeted identification of potentially bioactive molecules from herbal medicines is often stymied by the insufficient chromatographic separation, ubiquitous matrix interference, and pervasive isomerism. An enhanced targeted identification strategy is presented and validated by the selective identification of flavonoid O-glycosides (FOGs) from Carthamus tinctorius. It consists of four steps: (i) enhanced separation and detection by offline two-dimensional liquid chromatography/LTQ-Orbitrap MS (offline 2D-LC/LTQ-Orbitrap MS) using collision-induced dissociation (CID) and high-energy C-trap dissociation (HCD); (ii) improved identification of the major aglycones by acid hydrolysis and LC-SPE-NMR; (iii) simplified spectral elucidation by high-resolution diagnostic product ions/neutral loss filtering; and (iv) more convincing structural identification by matching an in-house library. An offline 2D-LC system configuring an Acchrom XAmide column and a BEH Shield RP-18 UPLC^® column enabled much better separation of the easily co-eluting components. Combined use of CID and HCD could produce complementary fragmentation information. The intensity ratios of the aglycone ion species ([Y₀-H]^-/Y₀^- and [Y₀-2H]^-/Y₀^-) in the HCD-MS² spectra were found diagnostic for discriminating the aglycone subtypes and characterizing the glycosylation patterns. Five aglycone structures (kaempferol, 6-hydroxykaempferol, 6-methoxykaempferol, carthamidin, and isocarthamidin) were identified based on the ¹H-NMR data recorded by LC-SPE-NMR. Of the 107 characterized flavonoids, 80 FOGs were first reported from C. tinctorius. Unknown aglycones, pentose, and novel acyl substituents were discovered. A new compound thereof was isolated and fully identified, which could partially validate the MS-oriented identification. This integral strategy can improve the potency, efficiency, and accuracy in the detection of new compounds from medicinal herbs and other natural sources.

Tenuifolin, a saponin derived from Radix Polygalae, exhibits sleep-enhancing effects in mice

BACKGROUND

Radix Polygalae, the dried root of Polygala tenuifolia, has been extensively used as a traditional Chinese medicine for promoting intelligence and tranquilization. Polygalasaponins extracted from the root of P. tenuifolia possess evident anxiolytic and sedative-hypnotic activities. Previous studies have reported that tenuifolin was a major constituent of polygalasaponins.

PURPOSE

The currently study aims to investigate the hypnotic effect and possible mechanism of tenuifolin in freely moving mice.

DESIGN/METHODS

The hypnotic effects of tenuifolin (20, 40 and 80mg/kg, p.o.) were assessed by electroencephalographic (EEG) and electromyographic (EMG) analysis. Double-staining immunohistochemistry test was performed to evaluate the neuronal activity of sleep-wake regulating brain areas. High performance liquid chromatograph- electrochemical detection (HPLC-ECD) and ultrafast liquid chromatography-mass spectrometry (UFLC-MS) were used for the detection of neurotransmitters. Locomotor activity was measured by Open-field Test.

RESULTS

Tenuifolin at doses of 40 and 80mg/kg (p.o.) significantly prolonged the total sleep time by increasing the amount of non-rapid eye movement (NREM) and rapid eye movement (REM) sleep, associated with the significant increase in the bouts of episodes respectively. After administration of tenuifolin, the cortical EEG power spectral densities during NREM and REM sleep were similar to that of natural sleep (vehicle) and thus compatible with physiological sleep. Double-immunohistochemistry staining test showed that tenuifolin increased the c-Fos positive ratios of GABAergic NREM sleep-promoting neurons in ventrolateral preoptic area (VLPO), cholinergic REM sleep-promoting neurons in laterodorsal tegmental area (LDT) and pontomesencephalic tegmental area (PPT) and decreased the c-Fos positive ratios in wake-promoting neurons (locus coeruleus (LC) and perifornical area (Pef)). Neurotransmitter detections revealed that tenuifolin significantly reduced the noradrenaline (NA) levels in LC, VLPO, PPT and LDT, elevated the GABA levels in VLPO, LC and Pef and increased the acetylcholine (Ach) levels in LDT and PPT. In addition, tenuifolin did not cause any change to locomotor activity.

CONCLUSION

Taken together, these results provide the first experimental evidence of the significant sleep-enhancing effect of tenuifolin in mice. This effect appears to be mediated, at least in part, by the activation of GABAergic systems and/or by the inhibition of noradrenergic systems. Moreover, this study adds new scientific evidence and highlights the therapeutic potential of the medicinal plant P. tenuifolia in the development of phytomedicines with hypnotic properties.

Selective and comprehensive characterization of the quinochalcone C-glycoside homologs in Carthamus tinctorius L. by offline comprehensive two-dimensional liquid chromatography/LTQ-Orbitrap MS coupled with versatile data mining strategies

An offline 2D LC/LTQ-Orbitrap MS approach and versatile data mining techniques were developed to characterize new QCGs from C. tinctorius.

Selective ion monitoring of quinochalcone C-glycoside markers for the simultaneous identification of Carthamus tinctorius L. in eleven Chinese patent medicines by UHPLC/QTOF MS

Current China Pharmacopoeia standards for the Chinese patent medicines (CPMs) that contain one or several the same drug(s) employ case-dependent TLC or HPLC approaches to achieve qualitative identification. A qualitative "monomethod-heterotrait matrix" (MHM) strategy is thus proposed, by selective monitoring of multi-biomarkers, to achieve the identification of different CPMs. Carthamus tinctorius L. (safflower) is a reputable gynecological herbal medicine containing characteristic quinochalcone C-glycosides (QCGs) as the major bioactive components. Qualitative identification of safflower in diverse CPMs by selective monitoring of QCG markers was performed by use of the MHM strategy. Initially, 27 QCG analogs (involving 16 potentially new ones) were selectively characterized by product ion filtering (m/z 119.05) and integrated analysis of the negative mode MS(E) and Fast DDA data obtained on a UHPLC/QTOF mass spectrometer. Subsequently, by fingerprint analysis of 20 batches of safflower samples followed by a thermostable test, six QCGs (hydroxysafflor yellow A and its two isomers, anhydrosafflor yellow B, safflomin C, and isosafflomin C) were selected as the biomarkers for safflower. Then, a highly specific selective ion monitoring (SIM) method by recording centroided data was developed and applied to selectively profile six QCG biomarkers from 28 batches of CPM samples collected from versatile vendors. By reference to a standard SIM spectrum established using a home-made safflower reference extract, simultaneous identification of safflower in eleven different CPMs was accomplished with the unified sample preparation and a single UHPLC/QTOF-SIM method. The qualitative MHM strategy represents the novel methodology that facilitates the quality control of CPMs more efficiently.

Types, principle, and characteristics of tandem high-resolution mass spectrometry and its applications

We review the principle and functional characteristics of different types or models for THRMS and provide a brief description of its applications in medical research, food safety, and environmental protection fields.