UPLC-QTOF-MS/MS based screening and identification of the metabolites in rat bile after oral administration of imperatorin

Characterization of chemical ingredients and in rats metabolic profiling of Lingyang Qingfei pills via ultra-high-performance liquid chromatography combined with Quadrupole-Exactive Orbitrap high-resolution mass spectrometry

Lingyang Qingfei pills (LQP), the renowned traditional Chinese medicine recipe, have been extensively utilized for the therapy of xerostomia, sore throat, bronchiolitis, and pneumonia in clinics. However, its phytochemicals remain equivocal, which severely limits the development of quality control and activity mechanisms. In the current research, a trusted method founded on ultra-high performance liquid chromatography with Quadrupole-Exactive Orbitrap mass spectrometry technique was proposed for the comprehensive screening of in vitro and in vivo chemical compositions of LQP. As a consequence, 239 constituents were preliminarily characterized, 37 of which were accurately confirmed by reference standards. In addition, a total of 208 xenobiotics, containing 71 absorbed prototypes and 137 metabolites, were revealed in rat plasma, bile, urine, and feces, respectively. The metabolic reaction of hydrolysis, hydroxylation, methylation, glycosylation, sulfation, and mixed-mode was detected in the biotransformations of flavonoids, terpenoids, alkaloids, anthraquinones, organic acids, phenylpropanoids, and so forth. And 12 of the metabolites were new compounds. This experiment acted as the first reference for chemical substances and metabolites of LQP, which could provide valuable chemical information for further clarifying pharmacodynamic substances and pharmacokinetic studies.

Detection and identification of imperatorin metabolites in rat, dog, monkey, and human liver microsomes by ultra-high-performance liquid chromatography combined with high-resolution mass spectrometry and Compound Discoverer software

Imperatorin, a furanocoumarin that widely exists in many umbelliferous herbs, has been demonstrated to have a variety of pharmacological effects, including anti-inflammatory, antiosteoporosis, and antitumor activities. The purpose of this study was to investigate the metabolism of imperatorin using liver microsomes. The metabolites were generated by individually incubating imperatorin with rat, dog, monkey, and human liver microsomes. To trap the reactive metabolites during microsomal metabolism, glutathione (GSH) was included in the incubation. A LC technique coupled with benchtop orbitrap MS with full mass/data-dependent tandem mass spectrometry acquisition mode was used to detect and identify the generated metabolites. The possible structures of the metabolites were characterized according to their accurate masses and fragment ions. Under the current conditions, a total of 10 metabolites, including four GSH adducts, were identified. The results indicated that imperatorin underwent extensive metabolic reactions including hydroxylation, oxidation, glucuronidation, and GSH conjugation. This study provides essential data on the metabolism of imperatorin, which will be helpful for us to understand the safety and efficacy of this bioactive compound.

Mechanism Repositioning Based on Integrative Pharmacology: Anti-Inflammatory Effect of Safflower in Myocardial Ischemia–Reperfusion Injury

Safflower (Carthamus tinctorius. L) possesses anti-tumor, anti-thrombotic, anti-oxidative, immunoregulatory, and cardio-cerebral protective effects. It is used clinically for the treatment of cardio-cerebrovascular disease in China. This study aimed to investigate the effects and mechanisms of action of safflower extract on myocardial ischemia–reperfusion (MIR) injury in a left anterior descending (LAD)-ligated model based on integrative pharmacology study and ultra-performance liquid chromatography–quadrupole time-of-flight-tandem mass spectrometer (UPLC-QTOF-MS/MS). Safflower (62.5, 125, 250 mg/kg) was administered immediately before reperfusion. Triphenyl tetrazolium chloride (TTC)/Evans blue, echocardiography, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay, lactate dehydrogenase (LDH) ability, and superoxide dismutase (SOD) levels were determined after 24 h of reperfusion. Chemical components were obtained using UPLC-QTOF-MS/MS. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were used to analyze mRNA and protein levels, respectively. Safflower dose-dependently reduced myocardial infarct size, improved cardiac function, decreased LDH levels, and increased SOD levels in C57/BL6 mice. A total of 11 key components and 31 hub targets were filtered based on the network analysis. Comprehensive analysis indicated that safflower alleviated inflammatory effects by downregulating the expression of NFκB1, IL-6, IL-1β, IL-18, TNFα, and MCP-1 and upregulating NFκBia, and markedly increased the expression of phosphorylated PI3K, AKT, PKC, and ERK/2, HIF1α, VEGFA, and BCL2, and decreased the level of BAX and phosphorylated p65. Safflower shows a significant cardioprotective effect by activating multiple inflammation-related signaling pathways, including the NFκB, HIF-1α, MAPK, TNF, and PI3K/AKT signaling pathways. These findings provide valuable insights into the clinical applications of safflower.

An ultra-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry method based on a four-step analysis strategy to investigate metabolites of Qi-Yu-San-Long decoction in rat plasma

Metabolism is undoubtedly significantly correlated with the efficacy and safety of traditional Chinese medicine. In clinic, Qi-Yu-San-Long decoction (QYSLD) has achieved good results in the treatment of non-small-cell lung cancer (NSCLC). Nevertheless, a detailed understanding of the compounds (prototypes and metabolites) of QYSLD and its dynamic metabolic profile in plasma has not been revealed.

METHODS

In this study, a rapid and sensitive method based on ultra-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF/MS^E ), combined with a four-step analysis strategy, was established to investigate QYSLD metabolic profile in rat plasma.

RESULTS

In all, 101 xenobiotics (41 prototypes and 60 QYSLD-related metabolites) were identified in rat plasma. The research uncovered metabolic profiles of alkaloids, saponins, flavonoids, iridoids, anthraquinones, and phenylpropanoids of QYSLD in rat plasma. The dynamic changes in these xenobiotics were also observed at different time intervals. At 0.5 h after oral administration, only 15 prototypes and 11 metabolites were detected. Within 24 h, 4 prototypes and 20 metabolites can still be detected. Four prototypes and 10 metabolites had the phenomenon of emergence-disappearance-reappearance in vivo.

CONCLUSION

In rat plasma, 101 xenobiotics of QYSLD were identified and their dynamic metabolic profiles were systematically delineated, which laid a material basis for further research of the pharmacodynamic substances of QYSLD inhibiting NSCLC.

UPLC-QTOF-MS Based Comparison of Rotundic Acid Metabolic Profiles in Normal and NAFLD Rats

Rotundic acid, the principal bioactive constituent of the herbal remedy "Jiubiying", has been considered as a candidate compound for treating non-alcoholic fatty liver disease (NAFLD). However, the in vivo and in vitro metabolism of rotundic acid has remained unclear. With the aim of elucidating its metabolic profile, a reliable approach that used ultra-high performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was applied for screening and identifying rotundic acid in vivo (plasma, feces, urine, and liver tissue of normal and NAFLD model rats) and in vitro (rat liver microsomes) metabolites. Herein, 26 metabolites of rotundic acid were identified, including 22 metabolites in normal rats, 20 metabolites in NAFLD model rats, and eight metabolites in rat liver microsomes. Among them, 17 metabolites were identified for the first time. These data illustrate that the pathological status of NAFLD affects the metabolism of rotundic acid. Furthermore, the major pathways of metabolism included phase Ⅰ (demethylation, desaturation, etc.) and phase Ⅱ (sulfation and glucuronidation) reactions, as well as a combined multiple-step metabolism. This work provides important information on the metabolism of rotundic acid and lays the foundation for its future clinical application.

Rapid characterization and identification of the chemical constituents and the metabolites of Du-zhi pill using UHPLC coupled with quadrupole time-of-flight mass spectrometry

A reliable method using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was established to conduct a comprehensive analysis of the chemical constituents of Du-zhi pill (DZP) as well as their metabolites in rat plasma, urine and feces after gastric perfusion. The efficient on-line mass data acquisition modes combined the various off-line mass data mining strategy was applied. A full mass scan was performed, and then accurate MS/MS datasets were obtained through the use of a multiple mass defect filter (MMDF) and dynamic background subtraction (DBS)-dependent data acquisition method. Furthermore, post-acquisition data processing was conducted using various data-mining tools, including extracted ion chromatography (XIC), mass defect filtering (MDF), product ion filtering (PIF), and neutral loss filtering (NLF) (MetabolitePilot™). Finaly, a total of 176 compounds were identified or tentatively characterized in DZP. Moreover, a total of 233 components in vivo, which includes 92 prototype components and 141 metabolites, were unambiguously or tentatively identified in rat plasma, urine and feces. The metabolic pathways, including phase I reactions (hydroxylation, dehydroxylation and hydrogenation) and phase II reactions (acetylation, sulfation, glucuronidation and methylation), for the absorbed constituents, were explored and summarized. This is the first systematic study on the components of DZP and their metabolites in vivo. This study provide a valid analytical strategy for the characterization of chemical compounds and metabolites of TCM formulas. Moreover, an integrative strategy was proposed for the characterization and identification of chemical constituents and metabolites for additional TCM prescriptions.

Characteristics and candidate genes associated with excellent stalk strength in maize (Zea mays L.)

Lodging is a major problem in maize production, which seriously affects yield and hinders mechanized harvesting. Improving stalk strength is an effective way to improve lodging. The maize inbred line Jing2416 (J2416) was an elite germplasm in maize breeding which had strong stalk mechanical strength. To explore the characteristics its stalk strength, we conducted physiological, metabolic and transcriptomic analyses of J2416 and its parents Jing24 (J24) and 5237. At the kernel dent stage, the stalk rind penetrometer strength of J2416 was significantly higher than those of its two parents in multiple environments. The rind thickness, sclerenchyma tissue thickness, and cellulose, hemicellulose, and lignin contents of J2416 were significantly higher than those of its parents. Based on the significant differences between J2416 and 5237, we detected metabolites and gene transcripts showing differences in abundance between these two materials. A total of 212 (68.60%) metabolites and 2287 (43.34%) genes were up-regulated in J2416 compared with 5237. The phenylpropanoid and glycan synthesis/metabolism pathways were enriched in metabolites and genes that were up-regulated in J2416. Twenty-eight of the up-regulated genes in J2416 were involved in lignin, cellulose, and hemicellulose synthesis pathways. These analyses have revealed important physiological characteristics and candidate genes that will be useful for research and breeding of inbred lines with excellent stalk strength.

An integrated strategy for comprehensive characterization of metabolites and metabolic profiles of bufadienolides from Venenum Bufonis in rats

Comprehensive characterization of metabolites and metabolic profiles in plasma has considerable significance in determining the efficacy and safety of traditional Chinese medicine (TCM) in vivo. However, this process is usually hindered by the insufficient characteristic fragments of metabolites, ubiquitous matrix interference, and complicated screening and identification procedures for metabolites. In this study, an effective strategy was established to systematically characterize the metabolites, deduce the metabolic pathways, and describe the metabolic profiles of bufadienolides isolated from Venenum Bufonis in vivo. The strategy was divided into five steps. First, the blank and test plasma samples were injected into an ultra-high performance liquid chromatography/linear trap quadrupole-orbitrap-mass spectrometry (MS) system in the full scan mode continuously five times to screen for valid matrix compounds and metabolites. Second, an extension-mass defect filter model was established to obtain the targeted precursor ions of the list of bufadienolide metabolites, which reduced approximately 39% of the interfering ions. Third, an acquisition model was developed and used to trigger more tandem MS (MS/MS) fragments of precursor ions based on the targeted ion list. The acquisition mode enhanced the acquisition capability by approximately four times than that of the regular data-dependent acquisition mode. Fourth, the acquired data were imported into Compound Discoverer software for identification of metabolites with metabolic network prediction. The main in vivo metabolic pathways of bufadienolides were elucidated. A total of 147 metabolites were characterized, and the main biotransformation reactions of bufadienolides were hydroxylation, dihydroxylation, and isomerization. Finally, the main prototype bufadienolides in plasma at different time points were determined using LC-MS/MS, and the metabolic profiles were clearly identified. This strategy could be widely used to elucidate the metabolic profiles of TCM preparations or Chinese patent medicines in vivo and provide critical data for rational drug use.

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Extension-mass defect filter model could reduce about 39% interfering ions.

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The optimized acquisition mode enhanced about 4 times acquisition capability than regular DDA mode.

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147 metabolites were characterized with metabolic network prediction, and the metabolic pathways were deduced in plasmas.

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The quantitative method of 14 prototypes was established by LC-MS/MS for metabolic profiles study.

Characterisation of hederacoside C metabolites using ultrahigh-performance liquid chromatography quadrupole Orbitrap mass spectrometry based on automatic fragment ion search

INTRODUCTION

Hederacoside C (HDC) is a bioactive natural triterpenoid saponins constituent originating from traditional Chinese medicines, playing an important role in the treatment of acute respiratory infections and chronic inflammatory bronchitis. Meanwhile, it is recognised by Korea as a botanical drug.

OBJECTIVES

In order to develop an integrated template approach to analysing screening and identification of the metabolites of traditional Chinese medicines. This study will provide available information for further pharmaceutical studies of HDC and other triterpene saponins.

METHODOLOGY

An analysis strategy based on ultrahigh-performance liquid chromatography quadrupole Orbitrap mass spectrometry (UHPLC-Q-Orbitrap-MS) technique combined with automatic fragment ion search (FISh) was firstly exploited for the characterisation metabolites of HDC in vivo and in vitro. Accurate full mass scan combined with an on-line FISh annotations approach was developed to rapidly identify all the potential metabolites of HDC. Furthermore, FISh accurately located the structure of the target compound in a large number of mass spectral data.

RESULTS

A total of 34 metabolites were detected and tentatively identified by analysing comprehensive biological samples. The results clearly demonstrated that HDC underwent general metabolic reactions including dealkylation, reduction, oxidation, desaturation, dehydration, cysteine conjugation, GSH conjugation, taurine conjugation, and glycine conjugation to produce 26 phase I and eight phase II metabolites.

CONCLUSION

In the present study, UHPLC-Q-Exactive Orbitrap MS technique combined with FISh provided a rapid and efficient platform to characterise metabolites of HDC in vivo and in vitro. The proposed method could develop an integrated template approach to screen and identify the constituents and metabolites of traditional Chinese medicines.

Imperatorin: A review of its pharmacology, toxicity and pharmacokinetics

As a naturally occurring furanocoumarin, the medicinal value of imperatorin has been studied more and more. We hope to provide useful information for the further development of imperatorin by analyzing the literature of imperatorin in recent years. By collating the literature on the pharmacology of imperatorin, we found that the pharmacological activity of imperatorin is wide and imperatorin can be used for anti-cancer, neuroprotection, anti-inflammatory, anti-hypertension and antibacterial. In addition, we found that some researchers confirmed the toxicity of imperatorin. Pharmacokinetic studies demonstrated that oxidation metabolism is the main metabolic pathways of imperatorin. At present, the shortcomings of research on imperatorin mainly include: most pharmacological studies are concentrated in vitro, lacking enough in vivo experimental data; more and more studies showed that imperatorin has synergistic effect with other drugs in anticancer and other aspects, but lacking the detailed explanation of the mechanism of the synergistic effect; imperatorin has side effect, but it lacks enough experimental conclusions. Based on the above defects, we believe that more in vivo experiments of imperatorin should be carried out in the future; future research need to explore synergistic mechanisms of imperatorin with other drugs, especially in anticancer; the dose affects both the pharmacological activity and the side effect of imperatorin. The relationship between the dose and the two aspects need to be further studied in order to reduce the side effect. In addition, through structural modification of imperatorin, it is possible to improve the treatment effect and reduce side effect.

Characterization of polymethoxyflavone demethylation during drying processes of citrus peels

Polymethoxyflavones (PMFs) are found almost exclusively in citrus peel and have attracted much attention due to their potential health benefits. Dried citrus peel is an important ingredient for applications in food and traditional Chinese medicine. However, the structural changes of PMFs during drying processes of citrus peel remain unknown. In this study, for the first time we discovered that four major permethoxylated PMFs, i.e. sinensetin, nobiletin, heptamethoxyflavone and tangeretin, underwent demethylation at the 5-position on the A ring of their flavonoid structures to yield corresponding 5-demethylated PMFs during the drying process of citrus peel. Our results further demonstrated that the aforementioned PMF demethylation was through two mechanisms: acid hydrolysis and enzyme-mediated catalysis. PMF demethylation in citrus peels was systematically characterized during hot-air drying (HAD), vacuum-freeze drying (VFD) and sun drying (SD). The highest PMF demethylation was obtained in SD followed by HAD and VFD. This study provided a solid scientific basis for rational control of PMF demethylation in citrus peels, which could facilitate the production of high-quality citrus peel and related products.

Recent Advances on Drug Analyses Using Ultra Performance Liquid Chromatographic Techniques and their Application to the Biological Samples

Introduction:

Ultra-Performance Liquid Chromatographic (UPLC) method enables analyst to establish an analysis at higher pressure than High Performance Liquid Chromatographic (HPLC) method towards liquid chromatographic methods. UPLC method provides the opportunity to study a higher pressure compared to HPLC, and therefore smaller column in terms of particle size and internal diameter are generally used in drug analysis. The UPLC method has attracted gradually due to its advantages such as short analysis time, the small amount of waste reagents and the significant savings in the cost of their destruction process. In this review, the recent selected studies related to the UPLC method and its method validation are summarized. The drug analyses and the results of the studies which were investigated by UPLC method, with certain parameters from literature are presented.

Background:

Quantitative determination of drug active substances by High-Performance Liquid Chromatography (HPLC) from Liquid Chromatography (LC) methods has been carried out since the 1970's with the use of standard analytical LC methods. In today's conditions, rapid and very fast even ultra-fast, flow rates are achieved compared to conventional HPLC due to shortening analysis times, increasing method efficiency and resolution, reducing sample volume (and hence injection volume), reducing waste mobile phase. Using smaller particles, the speed and peak capacity are expanding to new limit and this technology is named as Ultra Performance Liquid Chromatography. In recent years, as a general trend in liquid chromatography, ultra-performance liquid chromatography has taken the place of HPLC methods. The time of analysis was for several minutes, now with a total analysis time of around 1-2 minutes. The benefits of transferring HPLC to UPLC are much better understood when considering the thousands of analyzes performed for each active substance, in order to reduce the cost of analytical laboratories where relevant analysis of drug active substances are performed without lowering the cost of research and development activities.

Methods:

The German Chemist Friedrich Ferdinand Runge, proposed the use of reactive impregnated filter paper for the identification of dyestuffs in 1855 and at that time the first chromatographic method in which a liquid mobile phase was used, was reviewed. Christian Friedrich Chönbein, who reported that the substances were dragged at different speeds in the filter paper due to capillary effect, was followed by the Russian botanist Mikhail S. Tswet, who planted studies on color pigment in 1906. Tswet observes the color separations of many plant pigments, such as chlorophyll and xanthophyll when he passes the plant pigment extract isolated from plant through the powder CaCO3 that he filled in the glass column. This method based on color separation gives the name of "chromatographie" chromatography by using the words "chroma" meaning "Latin" and "graphein" meaning writing.

Results and Conclusion:

Because the UPLC method can be run smoothly at higher pressures than the HPLC method, it offers the possibility of analyzing using much smaller column sizes and column diameters. Moreover, UPLC method has advantages, such as short analysis time, the small amount of waste reagents and the significant savings in the cost of their destruction process. The use of the UPLC method especially analyses in biological samples such as human plasma, brain sample, rat plasma, etc. increasingly time-consuming due to the fact that the analysis time is very short compared to the HPLC, because of the small amount of waste analytes and the considerable savings in their cost.

Metabolites study on 5-O-methylvisammioside in vivo and in vitro by ultra high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

5-O-Methylvisammioside is one of major chromones of Radix Saposhnikoviae possessing definite pharmacological activities, but there are few reports with respect to the metabolism of 5-O-methylvisammioside. In this work, metabolites in vivo were explored in male Sprague-Dawley rats and in vitro investigated on rat intestinal bacteria incubation model and were identified by using ultra high performance liquid chromatography/quadrupole time-of-flight mass spectrometry. An online data acquisition method based on a multiple mass defect filter and dynamic background subtraction was developed to trace all probable metabolites. As a result, 26 metabolites in vivo (including 18, 15, 10, and 10 in rat urine, faece, bile, and blood) and 7 metabolites in vitro were characterized, respectively. Additionally, the main metabolic pathways in vivo and in vitro, including deglycosylation, deglycosylation + demethylation, deglycosylation + oxidation, N-acetylation, and sulfate conjugation, were summarized by calculating the relative content of each metabolite. The obtained results significantly enriched our knowledge about 5-O-methylvisammioside metabolism and will lead to a better understanding of its safety and efficacy.

Simultaneous Determination of Six Coumarins in Rat Plasma and Metabolites Identification of Bergapten in Vitro and in Vivo

Coumarins are abundant in Umbelliferae and Rutaceae plants possessing varied pharmacological activities. The objectives of this study are to develop and validate the method for determination of six coumarins in rat plasma by liquid chromatography coupled with tandem mass spectrometry (LC-MS) and identify the metabolites of bergapten by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS), respectively. Data-dependent acquisition mode (DDA) was applied to trigger enhanced product ion (EPI) scans by analyzing multiple reaction monitoring (MRM) signals. An efficient data processing method "key product ions (KPIs)" was used for rapid detection and identification of metabolites as an assistant tool. The time to reach the maximum plasma concentration ( T_max) for the six compounds ranged from 1 to 6 h. A total of 24 metabolites of bergapten were detected in vitro and in vivo. The results could provide a basis for absorption and metabolism of coumarins.

A Metabolism-Based Synergy for Total Coumarin Extract of Radix Angelicae Dahuricae and Ligustrazine on Migraine Treatment in Rats

Radix Angelicae dahuricae, containing coumarins, which might affect cytochrome P450 enzyme (CYP450) activity, has been co-administered with ligustrazine, a substrate of CYP450s, for the clinical treatment of migraine. However, whether a pharmacokinetic-based synergy exists between Radix Angelicae dahuricae and ligustrazine is still unknown. In this study, the total coumarin extract (TCE) of Radix Angelicae dahuricae (50 mg/kg, orally) reinforced the anti-migraine activity of ligustrazine by declining head scratching, plasma calcitonin gene-related peptide, and serum nitric oxide, as well as increasing plasma endothelin levels in rats (p < 0.05). Moreover, the pharmacokinetic study reflected that TCE potentiated the area under the concentration⁻time curve of ligustrazine and prolonged its mean retention time in rats (p < 0.05). Besides, the IC₅₀ for TCE, imperatorin and isoimperatorin inhibiting ligustrazine metabolism were 5.0 ± 1.02, 1.35 ± 0.46, 4.81 ± 1.14 µg/mL in human liver microsomes, and 13.69 ± 1.11, 1.19 ± 1.09, 1.69 ± 1.17 µg/mL in rat liver microsomes, respectively. Moreover, imperatorin and isoimperatorin were CYP450s inhibitors with IC₅₀ < 10 µM for CYP1A2, 2C9, 2D6, and 3A4. Therefore, this study concluded that Radix Angelicae dahuricae could increase ligustrazine plasma concentration and then reinforce its pharmacological effect by inhibiting its metabolism through interference with CYP450s. This could be one mechanism for the synergy between Radix Angelicae dahuricae and ligustrazine on migraine treatment.

Metabolite identification of ursolic acid in mouse plasma and urine after oral administration by ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry

Ursolic acid (UA), a pentacyclic terpenoid carboxylic acid widely existing in various medicinal plants, has been reported to have multifarious biological activities such as anti-inflammatory, anticancer and antioxidant activities. In this paper, we analyzed the metabolic profile of UA in mice (including plasma and urine) by using ultra-high performance liquid chromatography (UPLC) coupled with a quadrupole time-of-flight (Q/TOF) method. Principal component analysis (PCA) was applied to differentiate the control and experimental groups. Potential biomarkers were filtered by using loading plots followed by further analysis with UPLC-Q/TOF-MS data. The results showed that 3 metabolites in plasma were identified as markers, one of which was UA and the others were UA epoxides, which belonged to phase I metabolites. Additionally, 5 phase II metabolites were tentatively identified in urine through an accurate mass and characteristic fragment ions. These data suggested that the biotransformation of UA undergoes the major metabolic reactions of the phase I metabolic route of olefin oxidation and phase II metabolic routes of glycine conjugation, glutathione conjugation and glucuronidation. This is the first report of analysis and characterization of the metabolites after the oral administration of UA in mice. The proposed metabolic pathways of UA in mice is also raised for the first time. It might provide further understanding of the potential biological mechanism of UA.

First report on metabolism study of ursolic acid (UA) in vivo of mice.

Nontargeted SWATH acquisition mode for metabolites identification of osthole in rats using ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

Osthole (OST), 7-methoxy-8-isopentenoxycoumarin, is the characteristic constituent found in Cnidium monnieri (L.) Cuss. and possesses excellent pharmacological activities, including anticancer, anti-apoptosis and neuroprotection. In this study, a rapid and reliable method based on ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) and MetabolitePilot2.0™ software with principal component variable grouping (PCVG) filtering was developed to observe probable metabolites of OST firstly. The high resolution mass data were acquired by data-independent acquisition mode (DIA), i.e., sequential window acquisition of all theoretical fragmentation spectra (SWATH), which could significantly improved the hit rate of low-level and trace metabolites. A novel data processing method ‘key product ions (KPIs)’ were employed for metabolites rapid hunting and identification as an assistant tool. A total of 72 metabolites of OST were detected in vitro and in vivo, including 39 metabolites in rat liver microsomes (RLMs), 20 metabolites in plasma, 32 metabolites in bile, 32 metabolites in urine and 37 metabolites in feces. The results showed that mono-oxidation, demethylation, dehydrogenation, sulfate conjugation and glucuronide conjugation were major metabolic reactions of OST. More significant, oxydrolysis, 3,4-epoxide-aldehylation, phosphorylation, S-cysteine conjugation and N-acetylcysteine conjugation were considered as unique metabolic pathways of OST, and phosphorylation, S-cysteine conjugation and N-acetylcysteine conjugation reactions were characterized in rat biological samples for the first time. Preparation of active metabolites will be greatly helpful in elucidating the potential biological mechanism of OST, and the proposed metabolic pathways of it might provide further understanding of the safety and efficacy of simple coumarins.

Osthole (OST), 7-methoxy-8-isopentenoxycoumarin, is the characteristic constituent found in Cnidium monnieri (L.) Cuss. and possesses excellent pharmacological activities, including anticancer, anti-apoptosis and neuroprotection.

UHPLC-Q-TOF-MS/MS-based screening and characterization of metabolites of cnidilin in human liver microsomes

Cnidilin is an active natural furocoumarin ingredient originating from well-known traditional Chinese medicine Radix Angelicae Dahuricae. In the present study, an efficient approach was developed for the screening and identification of cnidilin metabolites using ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. In this approach, an on-line data acquisition method multiple mass defect filter combined with dynamic background subtraction was developed to trace all probable metabolites. Based on this analytical strategy, a total of 24 metabolites of cnidilin were detected in human liver microsomal incubation samples and the metabolic pathways were proposed. The results indicated that oxidation was the main biotransformation route for cnidilin in human liver microsomes. In addition, the specific cytochrome P450 (CYP) enzymes involved in the metabolism of cnidilin were identified using chemical inhibition and CYP recombinant enzymes. The results showed that CYP1A2 and CYP3A4 might be the major enzymes involved in the metabolism of cnidilin in human liver microsomes. The relationship between cnidilin and the CYP450 enzymes could provide us a theoretical basis of the pharmacological mechanism.

Simultaneous Determination of Three Furanocoumarins by UPLC/MS/MS: Application to Pharmacokinetic Study of Angelica dahurica Radix after Oral Administration to Normal and Experimental Colitis-Induced Rats

In traditional oriental medicine, Angelica dahurica Radix (ADR) is used in the treatment of gastrointestinal, respiratory, neuromuscular, and dermal disorders. We evaluated the pharmacokinetic profiles of oxypeucedanin, imperatorin, and isoimperatorin, major active ingredients of ADR, in normal and 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis rats. A rapid, sensitive, and validated UPLC/MS/MS method was established for evaluating the pharmacokinetics of three furanocoumarins. After oral administration of ADR (0.5 and 1.0 g/kg), blood samples were collected periodically from the tail vein. In colitis rats, the time to reach the peak concentration (T_max) of imperatorin and isoimperatorin was significantly delayed (p < 0.05). Lower peak plasma concentrations (C_max) and longer mean residence times for all furanocoumarins were also observed (p < 0.05) compared with normal rats. There was no significant difference in the area under the plasma concentration-time curve or elimination half-lives. Thus, the delayed T_max and decreased C_max, with no influence on the elimination half-life, could be colitis-related changes in the drug-absorption phase. Therefore, the prescription and use of ADR in colitis patients should receive more attention.