Structural elucidation and identification of alkaloids in Rhizoma Coptidis by electrospray ionization tandem mass spectrometry

Phytochemical Analysis of Nothapodytes tomentosa and Distribution and Content of Camptothecin and its Analogues in Four Plants

Camptothecin (CPT) and its derivatives have attracted worldwide attention because of their notable anticancer activity. However, the growing demand for CPT in the global pharmaceutical industry has caused a severe shortage of CPT-producing plant resources. In this study, phytochemical analysis of Nothapodytes tomentosa results in the isolation and identification of CPT (13: ) and 16 analogues (1:  - 12, 14:  - 17: ), including a new (1: ) and five known (9, 10, 12, 15: , and 17: ) CPT analogues with an open E-ring. In view of the potential anticancer activity of CPT analogues with an open E-ring, the fragmentation pathways and mass spectra profiles of these six CPT analogues (1, 9, 10, 12, 15: , and 17: ) are investigated, providing a reference for the rapid detection of these compounds in other plants. Furthermore, based on the fragmentation patterns of CPT (13: ) and known analogues (2:  - 8, 11, 14, 16, 18:  - 26: ), the distribution and content of these compounds in different tissues of N. tomentosa, N. nimmoniana, Camptotheca acuminata, and Ophiorrhiza japonica are further studied. Our findings not only provide an alternative plant resource for further expanding the development and utilization of CPT and its analogues, but also lay a foundation for improving the utilization of known CPT-producing plant resources.

Rapid analysis of components in Qizhiweitong tablets and plasma after oral administration in rats by UPLC-Q-TOF-MS/MS based on self-developed database

Qizhiweitong is a famous traditional Chinese prescription medicine. It has been used to treat various stomach disorders, such as functional dyspepsia, chronic gastritis, and intestinal stress syndrome for a long time and gives favorable therapeutic effects in clinical settings. However, its chemical composition and possible bioactive components are not completely known. In the present study, we used ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS) and qualitatively analyzed the chemical composition of Qizhiweitong tablet extract and the absorbed prototype constituents along with corresponding metabolites in rat plasma following oral administration of Qizhiweitong tablet on the basis of our self-developed component database that was established accurately and rapidly. We detected a total of 119 compounds and 61 xenobiotics in the Qizhiweitong tablet, which included 32 prototypes and 28 metabolites. The results of the present study laid a solid foundation for quality marker screening and integrative pharmacology-based study on the Qizhiweitong tablet.

The chromosome-level reference genome of Coptis chinensis provides insights into genomic evolution and berberine biosynthesis

Coptis chinensis Franch, a perennial herb, is mainly distributed in southeastern China. The rhizome of C. chinensis has been used as a traditional medicine for more than 2000 years in China and many other Asian countries. The pharmacological activities of C. chinensis have been validated by research. Here, we present a de novo high-quality genome of C. chinensis with a chromosome-level genome of ~958.20 Mb, a contig N50 of 1.58 Mb, and a scaffold N50 of 4.53 Mb. We found that the relatively large genome size of C. chinensis was caused by the amplification of long terminal repeat (LTR) retrotransposons. In addition, a whole-genome duplication event in ancestral Ranunculales was discovered. Comparative genomic analysis revealed that the tyrosine decarboxylase (TYDC) and (S)-norcoclaurine synthase (NCS) genes were expanded and that the aspartate aminotransferase gene (ASP5) was positively selected in the berberine metabolic pathway. Expression level and HPLC analyses showed that the berberine content was highest in the roots of C. chinensis in the third and fourth years. The chromosome-level reference genome of C. chinensis provides important genomic data for molecular-assisted breeding and active ingredient biosynthesis.

Study on the mechanisms of the cross-resistance to TET, PIP, and GEN in Staphylococcus aureus mediated by the Rhizoma Coptidis extracts

The purpose of this study was focused on the mechanisms of the cross-resistance to tetracycline (TET), piperacillin Sodium (PIP), and gentamicin (GEN) in Staphylococcus aureus (SA) mediated by Rhizoma Coptidis extracts (RCE). The selected strains were exposed continuously to RCE at the sublethal concentrations for 12 days, respectively. The susceptibility change of the drug-exposed strains was determined by analysis of the minimum inhibitory concentration. The 16S rDNA sequencing method was used to identify the RCE-exposed strain. Then the expression of resistant genes in the selected isolates was analyzed by transcriptome sequencing. The results indicated that RCE could trigger the preferential cross-resistance to TET, PIP, and GEN in SA. The correlative resistant genes to the three kinds of antibiotics were upregulated in the RCE-exposed strain, and the mRNA levels of the resistant genes determined by RT-qPCR were consistent with those from the transcriptome analysis. It was suggested from these results that the antibacterial Traditional Chinese Medicines might be a significant factor of causing the bacterial antibiotic-resistance.

Dissection of the potential pharmacological mechanism of Rhizoma coptidis water extract against inflammation in diabetes mellitus via chemical profiling, network pharmacology and experimental validation

Elucidating the therapeutical basis and functional mechanism of traditional Chinese medicine (TCM) is still a challenge faced by researchers since the effects of TCM are always achieved by the interactions of multiple components and multiple targets.

Investigation of fragmentation behaviours of isoquinoline alkaloids by mass spectrometry combined with computational chemistry

Isoquinoline alkaloids, which are one of the most important types of alkaloids, are extensively distributed in herbal medicines. However, systematic and comprehensive investigations of the fragmentation behaviours of isoquinoline alkaloids have rarely been reported. Therefore, the goal of the present study is to simultaneously investigate the collision-induced dissociation patterns and the corresponding mechanism of isoquinoline alkaloids by mass spectrometry (MS) combined with computations. Nineteen types of isoquinoline alkaloids (66 compounds) were used as references to identify the characteristic fragmentation behaviours by quadrupole time-of-flight mass spectrometry (Q-TOF/MS) in positive electrospray ionization (ESI) mode. These types of isoquinoline alkaloids were divided into three categories primarily by the characteristic [M-NHR₁R₂]⁺ (R₁ and R₂ represent the substituent groups of the N-atom) fragment ions. High- and low-abundance [M-NHR₁R₂]⁺ ions were observed respectively for type I (1–13) and type II (14–29) alkaloids, respectively; however, the characteristic fragments were not detected for type III alkaloids (30–66) because of the existence of a p-π conjugated system. Each type of alkaloid was further classified by its characteristic fragmentation patterns and fragment ions. In addition, isoquinoline alkaloid with vicinal methoxy and hydroxy, vicinal methoxy, methylenedioxy, methoxy, and quaternary N-methyl groups could form the characteristic fragments by the loss of CH₃OH, CH₄, CH₂O or CO, CH₃ and CO, and CH₃ moieties, respectively. The mechanisms of some interesting fragmentation behaviours, such as the formation of [M-NH₃]⁺ and [M-CH₃]⁺ fragment ions, were further demonstrated by computational chemistry. These characteristic fragmentation behaviours and fragment ions of isoquinoline alkaloids provide a solid foundation for the rapid and high-efficiency structural elucidation of similar metabolites in plant-derived medicines.

Simultaneous qualitative and quantitative evaluation of Toddalia asiatica root by using HPLC-DAD and UPLC-QTOF-MS/MS

INTRODUCTION

Coumarin and alkaloids are the major bioactive constituents of Toddalia asiatica, playing an important role in various biological activities such as anti-inflammatory, analgesic, anti-bacterial and anti-tumour.

OBJECTIVE

To establish a method that will simultaneously determine the coumarins and alkaloids compounds in T. asiatica and identify their characteristic fragmentation patterns, while combining fingerprints and chemical identification with chemometrics for discrimination and quality assessment of T. asiatica samples.

METHODOLOGY

Qualitative characterisation of coumarins and alkaloids compounds in the methanol extracts of T. asiatica was determined by ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS/MS). Quantitative analysis relies on high-performance liquid chromatography with a diode array detector (HPLC-DAD).

RESULTS

A total of 59 components were characterised by UPLC-QTOF-MS/MS, including 29 coumarin, 25 alkaloids, one phenolic acid and four flavonoids. While the 19 characteristic components out of 23 common peaks in the chromatographic fingerprints of T. asiatica were confirmed. Quantitative analysis of seven major compounds from 18 samples were simultaneously detected by HPLC-DAD at wavelengths of 280 nm. The samples were classified into three groups by hierarchical clustering analysis (HCA) combined with principal component analysis (PCA), and orthogonal partial least squares discriminant analysis (OPLS-DA) which screened out the main chemical markers responsible for the samples differences.

CONCLUSION

Fingerprints combined with chemometrics and chemical identification are a simple, rapid and effective method for the quality control of T. asiatica.

Comparing the antidiabetic effects and chemical profiles of raw and fermented Chinese Ge-Gen-Qin-Lian decoction by integrating untargeted metabolomics and targeted analysis

Background

Microbial fermentation has been widely applied in traditional Chinese medicine (TCM) for thousands of years in China. Various beneficial effects of fermentation for applications in TCM or herbals have been reported, such as enhanced anti-ovarian cancer, antioxidative activity, and neuroprotective effects. Ge-Gen-Qin-Lian decoction (GQD), a classic TCM formula, has been used to treat type 2 diabetes mellitus in China. In this study, GQD was fermented with Saccharomyces cerevisiae, and the antidiabetic activities and overall chemical profiles of raw and fermented GQD (FGQD) were systematically compared.

Methods

First, the antidiabetic effects of GQD and FGQD on high-fat diet and streptozotocin (STZ)-induced diabetic rats were compared. Then, high-performance liquid chromatography Q Exactive MS was applied for rapid characterization of the chemical components of GQD. Additionally, we proposed an integrated chromatographic technique based untargeted metabolomics identifying differential chemical markers between GQD and FGQD and targeted analysis determining the fermenting-induced quantitative variation tendencies of chemical marker strategy for overall chemical profiling of raw and fermented GQD.

Results

Both GQD and FGQD displayed effects against HFD and STZ-induced diabetes, and FGQD showed a better recovery trend associated with profound changes in the serum lipoprotein profile and body weight gain. In addition, 133 compounds were characterized from GQD. It was demonstrated that the integrated strategy holistically illuminated 30 chemical markers contributed to the separation of GQD and FGQD, and further elucidated the fermenting-induced chemical transformation mechanisms and inherent chemical connections of secondary metabolites. Although there were no new secondary metabolites in FGQD compared with GQD, the amounts of secondary metabolites, which were mostly deglycosylated, were redistributed in FGQD.

Conclusion

The anti-diabetic activities of GQD could be improved by applying fermentation technology. Moreover, the proposed strategy could serve as a powerful tool for systematically exploring the chemical profiles of raw and fermented formulas.

Electronic supplementary material

The online version of this article (10.1186/s13020-018-0208-7) contains supplementary material, which is available to authorized users.

Capillary-HPLC with tandem mass spectrometry in analysis of alkaloid dyestuffs - a new approach

Development of the identification method of alkaloid compounds in Amur cork tree as well as not examined so far Oregon grape and European Barberry shrubs are presented. The novel approach to separation of alkaloids was applied and the capillary-high-performance liquid chromatography (capillary-HPLC) system was used, which has never previously been reported for alkaloid-based dyestuffs analysis. Its optimization was conducted with three different stationary phases (unmodified octadecylsilane-bonded silica, octadecylsilane modified with polar groups and silica-bonded pentaflourophenyls) as well as with different solvent buffers. Detection of the isolated compounds was carried out using diode-array detector (DAD) and tandem mass spectrometer with electrospray ionization (ESI MS/MS). The working parameters of ESI were optimized, whereas the multiple reactions monitoring (MRM) parameters of MS/MS detection were chosen based on the product ion spectra of the quasi-molecular ions. Calibration curve of berberine has been estimated (y = 1712091x + 4785.03 with the correlation coefficient 0.9999). Limit of detection and limit of quantification were calculated to be 3.2 and 9.7 ng/mL, respectively. Numerous alkaloids (i.e., berberine, jatrorrhizine and magnoflorine, as well as phellodendrine, menisperine and berbamine) were identified in the extracts from alkaloid plants and silk and wool fibers dyed with these dyestuffs, among them their markers.

Identification of Metabolites of the Cardioprotective Alkaloid Dehydrocorydaline in Rat Plasma and Bile by Liquid Chromatography Coupled with Triple Quadrupole Linear Ion Trap Mass Spectrometry

Dehydrocorydaline (DHC), a quaternary alkaloid from Corydalis yanhusuo, has been demonstrated to be the active constituent in the treatment of coronary heart disease. In this study, a high-performance liquid chromatography–electrospray ionization–triple quadrupole linear ion trap mass spectrometry (HPLC–ESI–QTRAP MS) technique was used to identify DHC metabolites in plasma and bile after oral administration of DHC to rats. A total of 18 metabolites (M1 to M18) were identified and characterized by LC–MS/MS in the positive ion mode. These 18 metabolites were all present in rat bile, while only 9 were detected in plasma. O-demethylation, hydroxylation, di-hydroxylation, glucuronidation of O-demethyl DHC, sulfation of O-demethyl DHC and di-hydroxylation of dehydro-DHC were the major metabolic pathways of DHC. This is the first time that these metabolites of DHC have been identified in rat plasma and bile, which provides useful information for further analysis of the biotransformation of DHC and other quaternary protoberberine-type alkaloids.

In vitro assessment of the glucose-lowering effects of berberrubine-9-O-β-D-glucuronide, an active metabolite of berberrubine

Berberrubine (BRB) is the primary metabolite of berberine (BBR) that has shown a stronger glucose-lowering effect than BBR in vivo. On the other hand, BRB is quickly and extensively metabolized into berberrubine-9-O-β-D-glucuronide (BRBG) in rats after oral administration. In this study we compared the pharmacokinetic properties of BRB and BRBG in rats, and explored the mechanisms underlying their glucose-lowering activities. C57BL/6 mice with HFD-induced hyperglycemia were administered BRB (50 mg·kg^-1·d^-1, ig) for 6 weeks, which caused greater reduction in the plasma glucose levels than those caused by BBR (120 mg·kg^-1·d^-1) or BRB (25 mg·kg^-1·d^-1). In addition, BRB dose-dependently decreased the activity of α-glucosidase in gut of the mice. After oral administration of BRB in rats, the exposures of BRBG in plasma at 3 different dosages (10, 40, 80 mg/kg) and in urine at different time intervals (0-4, 4-10, 10-24 h) were dramatically greater than those of BRB. In order to determine the effectiveness of BRBG in reducing glucose levels, we prepared BRBG from the urine pool of rats, and identified and confirmed it through LC-MS-IT-TOF and NMR spectra. In human normal liver cell line L-O2 in vitro, treatment with BRB or BRBG (5, 20, 50 μmol/L) increased glucose consumption, enhanced glycogenesis, stimulated the uptake of the glucose analog 2-NBDG, and modulated the mRNA levels of glucose-6-phosphatase and hexokinase. However, both BBR and BRB improved 2-NBDG uptake in insulin-resistant L-O2 cells, while BRBG has no effect. In conclusion, BRB exerts a stronger glucose-lowering effect than BBR in HFD-induced hyperglycemia mice. Although BRB significantly stimulated the insulin sensitivity and glycolysis in vitro, BRBG may have a greater contribution to the glucose-lowering effect because it has much greater system exposure than BRB after oral administration of BRB. The results suggest that BRBG is a potential agent for reducing glucose levels.

Compound to Extract to Formulation: a knowledge-transmitting approach for metabolites identification of Gegen-Qinlian Decoction, a traditional Chinese medicine formula

Herbal medicines usually contain a large group of chemical components, which may be transformed into more complex metabolites in vivo. In this study, we proposed a knowledge-transmitting strategy for metabolites identification of compound formulas. Gegen-Qinlian Decoction (GQD) is a classical formula in traditional Chinese medicine (TCM). It is widely used to treat diarrhea and diabetes in clinical practice. However, only tens of metabolites could be detected using conventional approaches. To comprehensively identify the metabolites of GQD, a “compound to extract to formulation” strategy was established in this study. The metabolic pathways of single representative constituents in GQD were studied, and the metabolic rules were transmitted to chemically similar compounds in herbal extracts. After screening diversified metabolites from herb extracts, the knowledge was summarized to identify the metabolites of GQD. Tandem mass spectrometry (MSⁿ), fragment-based scan (NL, PRE), and selected reaction monitoring (SRM) were employed to identify, screen, and monitor the metabolites, respectively. Using this strategy, we detected 131 GQD metabolites (85 were newly generated) in rats biofluids. Among them, 112 metabolites could be detected when GQD was orally administered at a clinical dosage (12.5 g/kg). This strategy could be used for systematic metabolites identification of complex Chinese medicine formulas.

Chemical profiling of San-Huang decoction by UPLC-ESI-Q-TOF-MS

San-Huang decoction (SHD), a traditional Chinese medical (TCM) formula, is made from five chinese herbs and has been widely used for centuries to treat metabolic syndrome, such as abdominal obesity and nonalcoholic fatty liver disease. In this work, an ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS) method in both positive and negative ion mode was first employed to rapidly survey the major constituents in SHD. The analysis was performed on a Waters Acquity UPLC BEH C18 column at 45°C within 17min. 56 compounds in SHD including alkaloids, flavonoids, protostane triterpenoids, coumarins, triterpenoid saponins, organic acids, lignans, lactones and chromones were identified and tentatively characterized by comparison with retention times, accurate mass within 5ppm error and MS fragmentation ions. Among them, twenty-two compounds were clearly identified mainly by the reference standards. Moreover, this method was respectively applied to determine five batches of SHD and the decoctions of relative individual herbs. These results provide a helpful basic chemical profile for further research of SHD in vivo and exploitation of new drug to treat metabolic syndrome.

Chemical profiling approach to evaluate the influence of traditional and simplified decoction methods on the holistic quality of Da-Huang-Xiao-Shi decoction using high-performance liquid chromatography coupled with diode-array detection and time-of-flight mass spectrometry

Da-Huang-Xiao-Shi decoction, consisting of Rheum officinale Baill, Mirabilitum, Phellodendron amurense Rupr. and Gardenia jasminoides Ellis, is a traditional Chinese medicine used for the treatment of jaundice. As described in "Jin Kui Yao Lue", a traditional multistep decoction of Da-Huang-Xiao-Shi decoction was required while simplified one-step decoction was used in recent repsorts. To investigate the chemical difference between the decoctions obtained by the traditional and simplified preparations, a sensitive and reliable approach of high-performance liquid chromatography coupled with diode-array detection and electrospray ionization time-of-flight mass spectrometry was established. As a result, a total of 105 compounds were detected and identified. Analysis of the chromatogram profiles of the two decoctions showed that many compounds in the decoction of simplified preparation had changed obviously compared with those in traditional preparation. The changes of constituents would be bound to cause the differences in the therapeutic effects of the two decoctions. The present study demonstrated that certain preparation methods significantly affect the holistic quality of traditional Chinese medicines and the use of a suitable preparation method is crucial for these medicines to produce special clinical curative effect. This research results elucidated the scientific basis of traditional preparation methods in Chinese medicines.

A new bisbenzylisoquinoline alkaloid isolated from Thalictrum foliolosum, as a potent inhibitor of DNA topoisomerase IB of Leishmania donovani

Chemical investigation of the stem of Thalictrum foliolosum resulted in the isolation of two new bisbenzylisoquinoline alkaloids (1 and 2) along with known protoberberine group of isoquinoline alkaloids thalifendine (3) and berberine (4). The structures of the new compounds were established by detailed 2D NMR spectral analysis with their configurations determined from their optical rotation values and confirmed using circular dichroism. Inhibitory activities of these four compounds against DNA topoisomerase IB of Leishmania donovani were evaluated. Compound 2 exhibited almost complete inhibition of the enzyme activity at 50 μM concentration and it was found to be effective in killing both wild type as well as SAG resistant promastigotes of the parasite.

Neuroprotective Activity of Coptisine from Coptis chinensis (Franch)

Coptis chinensis rhizomes (CR) are one important ingredient of traditional Chinese herbal formulas such as San-Huang-Xie-Xin-Tang which is used for treatment of cardiovascular and neurodegenerative diseases. Recent studies suggest that the extract of CR might be a potential therapeutic agent for amelioration of neurological disorders associated with oxidative stress. In the present study we aimed at revealing the main active compound(s) of the CR extract and at investigating the mechanism of action. Four main alkaloids of the CR extract (berberine, coptisine, jatrorrhizine, and palmatine) were selected for this study. Results showed that out of those alkaloids only pretreatment with coptisine significantly attenuated tert-butylhydroperoxide induced reduction of cell viability, increased rate of apoptosis, and declined mitochondrial membrane potential. Elisa assay and quantitative real-time PCR analyses revealed that thioredoxin-interacting protein (TXNIP) gene expression was downregulated by coptisine, which could explain the neuroprotective effect, hypothetically, by strengthening the thioredoxin defense system against oxidative stress and attenuation of apoptosis signal-regulating kinase (Ask1) mediated apoptotic signaling. A comparison between coptisine and CR extract identified coptisine as the main single component responsible for the neuroprotective effect. Based on the results the CR extract and coptisine are promising candidate agents for prevention or improvement of diabetic neuropathy and neurodegenerative disorders.

Identification of alkaloid constituents from Fangchi species using pH control liquid-liquid extraction and liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

RATIONALE

Fangchi (F.) species from four different origins have been widely used to treat or prevent diseases, and their main constitutes are several types of alkaloids. Identification of alkaloids in F. species is a necessary step to understand the therapeutic properties of each different origin, but this has not yet been fully performed.

METHODS

Several types of alkaloids were extracted from F. species using ultrasonication with 70% CH(3)OH and the extract was partitioned at pH 2 and 12 to enrich alkaloid constituents and to remove interferences. The separation of alkaloids in the Fangchi extract was performed on a C18 column using gradient elution and their tandem mass spectra were obtained by quadrupole time-of-flight tandem mass spectrometry (QTOF-MS/MS) to perform accurate mass measurements of fragment ions for the alkaloid constituents.

RESULTS

Several types of alkaloids were successfully separated and identified by LC/ESI-MS/MS. The structural assignment of individual alkaloids was performed based on convergence of MS/MS spectral data, pH partitioning behavior, LC retention behavior, and accurate mass measurements. The pH partition of the extract provided structural information about unknown alkaloids extracted from Fangchi species. A total of 28 compounds were identified and tentatively characterized, and of these 10 alkaloids were reported for the first time in the investigated F. species.

CONCLUSIONS

The chemical profiling of alkaloids in F. species with different origins was performed for the first time and provided diagnostic ions for diverse alkaloids in F. species. Marker compounds were suggested based on the 28 characterized compounds for quality evaluation and the differentiation of Fangchi species with four different origins.

Ion tree-based structure elucidation of acetophenone dimers (AtA) from Acronychia pedunculata and their identification in extracts by liquid chromatography electrospray ionization LTQ-Orbitrap mass spectrometry

Acronychia-type acetophenones (AtA) is a chemical group of compounds of important structural and biological interest, abundant in Acronychia species. However, there are no data available for their characterization using mass spectrometry. In the current work, AtA have been investigated by multistage high resolution mass spectrometry and both electrospray ionization and atmospheric pressure chemical ionization, in positive and negative mode, were utilized for their structure elucidation and identification. The analysis of AtA using a linear ion trap-Orbitrap analyzer enabled the structural determination of key fragment ions and cleavages, which can be used for the structural characterization thereof. A systematic nomenclature based on protonated and deprotonated fragment ions under collision-induced dissociation conditions and decision trees for the structural determination of AtA are proposed. Furthermore, taking advantage of the characteristic fragmentation patterns, a selective Ultra High Performance Liquid Chromatography Electrospray Ionization multistage Mass Spectrometry (UHPLC-ESI(-)-MS(n)) method was developed and successfully applied for the dereplication of known AtA and the identification of potentially new ones in Acronychia extracts. Despite the structure similarity and the presence of isomers, accurate characterization of known and unknown AtA derivatives was possible.

Identification of absorbed constituents and metabolites in rat plasma after oral administration of Shen-Song-Yang-Xin using ultra-performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry

In this study, a rapid and sensitive method by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry, and Metabolynx(TM) software with mass defect filter technique was developed for screening and identification of the metabolites in rat plasma after oral administration of Shen-Song-Yang-Xin capsule (SSYX). A total of 92 SSYX-related xenobiotics were identified or characterized, including 45 prototypes and 47 metabolites. The results indicated that the absorbed constituents and metabolites mainly came from benzocyclooctadiene lignans, tanshinones, isoquinoline alkaloids and triterpenic acids, while phase I reactions (e.g. hydrogenation, hydroxylation, demethylation) and phase II reaction (glucuronidation) were the main metabolic pathways of these ingredients in SSYX. This is the first study on metabolic profiling of SSYX in rat plasma after oral administration. Furthermore, these findings provide useful information on the potential bioactive compounds, and enhance our understanding of the action mechanism of SSYX.

Chemical Prospection of Important Ayurvedic Plant Tinospora cordifolia by UPLC-DAD-ESI-QTOF-MS/MS and NMR

A rapid, sensitive, and accurate ultra-performance liquid chromatography coupled with mass spectrometric method (UPLC-MS) was developed and validated for simultaneous determination of four bioactive compounds, syringin (3), cordifolioside A (4), magnoflorine (6) and tinocordiside (10) in the stem of Tinospora cordifolia. The analysis was performed using an Acquity C18 column and gradient elution of 0.05% formic acid in water and acetonitrile at a detection wavelength of 267 nm in 5 min. A high correlation coefficient (r2 > 0.998) indicated good correlation between investigated compounds concentration and their peak area within the test ranges. The LODs for compounds 3, 4, 6 and 10 were 1.95, 0.97, 3.90 and 0.97 ng/mL, respectively, and LOQs were 6.64, 3.20, 12.87 and 3.20 ng/mL, respectively. The overall intra- and inter-day variations of the four compounds were less than 1%. The variation of these four bioactive compounds in T. cordifolia hosted on fifteen different trees was also determined. The compounds (3, 4, 6 and 10) were found in high amount in the T. cordifolia hosted on Azadirachta indica and Mangifera indica as compared with other plants. Twelve compounds were identified on the basis of their mass and UV-vis spectra. The NMR fingerprinting of the extract revealed the presence of alkaloids, fatty acid methyl esters, polysaccharides and marker components of T. cordifolia.

In vitro studies of berberine metabolism and its effect of enzyme induction on HepG2 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Berberine (BER) and BER-original herbal medicines have a variety of pharmacological functions and have been widely used in clinical. However, its effect of enzyme induction on cytochrome P450 (CYP) in human hepatocytes is unknown.

MATERIAL AND METHOD

Metabolism of berberine and its effect on main metabolic enzymes in HepG2 cell in vitro was investigated. Cocktail probe drugs, mRNA expression and protein expression were used to evaluate the metabolism potency. Meanwhile, an UPLC-MS/MS method was validated for the analysis of BER and four probe drugs in HepG2 cell.

RESULT

BER significantly increased the metabolism of midazolam, phenacetin and tolbutamide by inducing the CYP1A2 and 3A4 enzyme in a dose-dependent manner, the mRNA and protein expression of CYP1A2 and 3A4 were increased by berberine at 1000ng·mL(-1). The activity of CYP1A2 and 3A4 could be induced by BER more than 500ng·mL(-1) in HepG2 cell, which was confirmed by the increase of its mRNA and protein expression.

CONCLUSION

BER increases the metabolism of cocktail drugs such as midazolam, phenacetin and tolbutamide by increasing the mRNA and protein expression of CYP1A2 and 3A4.

Differential detection of Rhizoma coptidis by capillary electrophoresis electrospray ionization mass spectrometry with a nanospray interface

A lab prototype CE-nanospray-MS platform with a high sensitivity porous sprayer was successfully applied in differential identification of Rhizoma coptidis in this paper. To obtain a stable and reliable nanospray, detailed optimizations about emitter geometry, buffer composition, emitter position, and spray voltage, as well as emitter cleanliness were discussed. Results showed that the reproducibility and sensitivity for separations of alkaloid standards were satisfactory using CE-nanospray-MS, which were also compared to ultra-HPLC (UHPLC)-MS. Their signal responds were at the same order of magnitude (intensities: 0.8 - 1.5 × 10(8) vs. 3.8 - 6.2 × 10(8) ), even though a 2 nL injection for CE was 2500-fold lower than UHPLC (5 μL injection). The absolute LOD results of CE-MS showed a remarkable superiority (18-24 fg), equal to 1000-fold lower than that of UHPLC-MS. Principal component analysis (PCA) of adulterated R. coptidis showed that this protocol had the ability to profile and qualify complex herb medicines, which also created a great potential for evaluation and qualification of rare and valuable Chinese medicines in future.

Coptis chinensis Franch. exhibits neuroprotective properties against oxidative stress in human neuroblastoma cells

ETHNOPHARMACOLOGICAL RELEVANCE

The dried rhizome of Coptis chinensis Franch. (family Ranunculaceae) is traditionally used in Chinese medicine for the treatment of inflammatory diseases and diabetes. Recent studies showed a variety of activities of Coptis chinensis Franch. alkaloids, including neuroprotective, neuroregenerative, anti-diabetic, anti-oxidative and anti-inflammatory effects. However, there is no report on the neuroprotective effect of Coptis chinensis Franch. watery extract against tert-butylhydroperoxide (t-BOOH) induced oxidative damage. The aim of the study is to investigate neuroprotective properties of Coptis chinensis Franch. rhizome watery extract (CRE) and to evaluate its potential mechanism of action.

MATERIALS AND METHODS

Neuroprotective properties on t-BOOH induced oxidative stress were investigated in SH-SY5Y human neuroblastoma cells. Cells were pretreated with CRE for 2 h or 24 h followed by 2 h of treatment with t-BOOH. To evaluate the neuroprotective effect of CRE, cell viability, cellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and the apoptotic rate were determined and microarray analyses, as well as qRT-PCR analyses were conducted.

RESULTS

Two hours of exposure to 100 µM t-BOOH resulted in a significant reduction of cell viability, increased apoptotic rate, declined mitochondrial membrane potential (MMP) and increased ROS production. Reduction of cell viability, increased apoptotic rate and declined mitochondrial membrane potential (MMP) could be significantly reduced in cells pretreated with CRE (100 µg/ml) for 2h or 24h ahead of t-BOOH exposure with the greatest effect after 24h of pretreatment; however ROS production was not changed significantly. Furthermore, microarray analyses revealed that the expressions of 2 genes; thioredoxin-interacting protein (TXNIP) and mitochondrially encoded NADH dehydrogenase 1, were significantly regulated. Down regulation of TXNIP was confirmed by qRT-PCR.

CONCLUSION

Due to its neuroprotective properties CRE might be a potential therapeutic agent for the prevention or amelioration of diseases like diabetic neuropathy and neurodegenerative disorders like Alzheimer and Parkinsons disease.

Structural speculation and identification of alkaloids in Macleaya cordata fruits by high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry combined with a screening procedure

RATIONALE

Alkaloids with significant therapeutic effects are the main active constituents of Macleaya cordata, which is a perennial herb plant in the Papaveraceae family. A systematic and novel method for speculating and identifying the structures of alkaloids in M. cordata fruits by high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (HPLC/Q-TOF-MS) with a screening procedure was reported.

METHODS

Investigation of mass spectral fragmentation of alkaloids was carried out based on the tandem mass spectrometry (MS/MS) data analyses of eight reference substances. The skeletons of alkaloids were determined by their ultraviolet spectra (UV) and MS/MS data. The substituent groups of the alkaloids were acquired through a screening procedure developed in our laboratory and MS/MS data. The substituent linkage sites were deduced by MS/MS fragmentation behavior, as well as biosynthetic pathways of related alkaloids.

RESULTS

The structures of 21 alkaloids were speculated in this study, 10 of which were reported for the first time in M. cordata. Furthermore, benzyltetrahydroisoquinoline and N-methyltetrahydroprotoberberine-type alkaloids were discovered, which indirectly proved that the biosynthetic pathways of benzophenanthridine alkaloids reported in Eschscholtzia california existed in M. cordata as well.

CONCLUSIONS

HPLC/Q-TOF-MS combined with a screening procedure was a systematic and reliable method for speculating and elucidating the structures of alkaloids. This study might be useful for the identification of other compounds in herbal medicines.

Quantitative and qualitative analysis of common peaks in chemical fingerprint of Yuanhu Zhitong tablet by HPLC-DAD-MS/MS

A quality control (QC) strategy for quantitative and qualitative analysis of "common peaks" in chemical fingerprint was proposed to analyze Yuanhu Zhitong tablet (YZT), using high performance liquid chromatography with diode array detector and tandem mass spectrometry (HPLC-DAD-MS/MS). The chromatographic separation was achieved on an Agilent Eclipse plus C₁₈ column with a gradient elution using a mixture of 0.4‰ ammonium acetate aqueous (pH 6.0 adjusted with glacial acetic acid) and acetonitrile. In chemical fingerprint, 40 peaks were assigned as the "common peaks". For quantification of "common peaks", the detection wavelength was set at 254 nm, 270 nm, 280 nm and 345 nm, respectively. The method was validated and good results were obtained to simultaneously determine 10 analytes (protopine, jatrorrhizine, coptisine, palmatine, berberine, xanthotoxin, bergapten, tetrahydropalmatine, imperatorin and isoimperatorin). For qualification of "common peaks", 33 compounds including 10 quantitative analytes were identified or tentatively characterized using LC-MS/MS. These results demonstrated that the present approach may be a powerful and useful tool to tackle the complex quality issue of YZT.

In Vitro Screening for Antihepatic Steatosis Active Components within Coptidis Rhizoma Alkaloids Extract Using Liver Cell Extraction with HPLC Analysis and a Free Fatty Acid-Induced Hepatic Steatosis HepG2 Cell Assay

A high-throughput method was developed and applied to screen for the active antihepatic steatosis components within Coptidis Rhizoma Alkaloids Extract (CAE). This method was a combination of two previously described assays: HepG2 cell extraction with HPLC analysis and a free fatty acid-induced (FFA) hepatic steatosis HepG2 cell assay. Two alkaloids within CAE, berberine and coptisine, were identified by HepG2 cell extraction with HPLC analysis as high affinity components for HepG2. These alkaloids were also determined to be active and potent compounds capable of lowering triglyceride (TG) accumulation in the FFA-induced hepatic steatosis HepG2 cell assay. This remarkable inhibition of TG accumulation (P < 0.01) by berberine and coptisine occurred at concentrations of 0.2 μg/mL and 5.0 μg/mL, respectively. At these concentrations, the effect seen was similar to that of a CAE at 100.0 μg/mL. Another five alkaloids within CAE, palmatine, epiberberine, jateorhizine, columbamine, and magnoline, were found to have a lower affinity for cellular components from HepG2 cells and a lower inhibition of TG accumulation. The finding of two potent and active compounds within CAE indicates that the screening method we developed is a feasible, rapid, and useful tool for studying traditional Chinese medicines (TCMs) in treating hepatic steatosis.

Characterization of protoberberine alkaloids in Coptidis Rhizoma (Huanglian) by HPLC with ESI-MS/MS

This study aims to qualitatively analyze protoberberine alkaloids in crude extract of Coptidis Rhizoma using HPLC with ESI-MS/MS. Possible specific molecular weights of protoberberine alkaloids were firstly deduced according to literatures and were adopted to screen the alkaloids in the HPLC with ESI-MS of crude extract of Coptidis Rhizoma. As a result, 21 protoberberine alkaloids were found, including compounds of very low concentration and compounds coeluted in one peak. Among these, two compounds were positively identified and verified by comparison with standards. Ten of these compounds were first reported in this study for Coptidis Rhizoma. In addition, chromatographic retention parameters a and c of all compounds were obtained using their retention times under five gradient conditions and were applied to confirm the deduction about the structures of protoberberine alkaloids by tandem mass data.

Antihyperglycemic effect of the traditional Chinese scutellaria-coptis herb couple and its main components in streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Scutellaria-coptis herb couple (SC) is the main herb couple in many traditional Chinese compound formulas used for the treatment of diabetes mellitus, which has been used to treat diabetes mellitus for thousands of years in China. In this study we provide experimental evidence for the clinical use of SC in the treatment of diabetes mellitus.

AIM OF THE STUDY

To confirm the anti-diabetic effect of SC extract and its main components, and to explore its mechanism from the effect on intestinal disaccharidases by in vivo and in vitro experiment.

MATERIALS AND METHODS

SC extract was prepared and the main components (namely berberine and baicalin) contained in the extract were assayed with high performance liquid chromatography (HPLC). And diabetic model rats were induced by intraperitoneal injection of streptozotocin (STZ). After grouped randomly, diabetic rats were administered SC extract, berberine, baicalin, berberine+baicalin, acarbose and vehicle for 33d, respectively. Body weight, food intake, urine volume, urine sugars, fasting plasma glucose and fasting plasma insulin were monitored to evaluate the antidiabetic effects on diabetic rats. Intestinal mucosa homogenate was prepared and the activities of intestinal disaccharidases were assayed. Moreover, oral sucrose tolerance test (OSTT) was performed and the inhibitory effects of SC extract and its main components (berberine and baicalin) on the maltase and sucrase in vitro was evaluated.

RESULTS

After the treatment of SC extract and its main components, the body weight and the fasting plasma insulin level were found to be increased while food intake, urine volume, urine sugars and fasting plasma were decreased. OSTT showed that SC extract and its main components could lower the postprandial plasma glucose level of diabetic rats. Furthermore, SC extract and its main components could inhibit the activities of intestinal disaccharidases in diabetic rats, whereas only SC extract and berberine could inhibit the activity of maltase in vitro.

CONCLUSIONS

According to our present findings, scutellaria-coptis herb couple (SC) possessed potent anti-hyperglycemic effect on STZ-induced diabetic rats. And SC extract and its main components exerted anti-hyperglycemic effect partly via inhibiting the increased activities of intestinal disaccharidases and elevating the level of plasma insulin in diabetic rats induced by STZ.

Identification of structurally diverse alkaloids in Corydalis species by liquid chromatography/electrospray ionization tandem mass spectrometry

RATIONALE

Alkaloids with significant therapeutic effects are the main active constituents of Corydalis (C.) species. There are several kinds of alkaloids in C. species associated with diverse alkaloid metabolism in plants, but they are rarely identified. This study aimed to identify diverse alkaloids in C. species by liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS).

METHODS

Several types of alkaloids were extracted from C. species using ultrasonication with 70% CH(3)OH, and the extract was partitioned at pH 2 and 12. Separation of alkaloids was achieved by C18 high-performance liquid chromatography (HPLC), and MS/MS analysis was conducted by electrospray ionization triple-quadrupole mass spectrometry. For further confirmation, LC/Fourier transform ion cyclotron resonance (FTICR)-MS was used to obtain accurate mass data and gas chromatography (GC)/MS combined with trimethylsilyl derivatization was applied for identification of the minor alkaloids.

RESULTS

Thirty-three alkaloids among three different C. species were successfully separated and identified by LC/ESI-MS/MS and LC/FTICR-MS. Structural assignment of individual alkaloids was performed according to MS/MS spectral patterns. For further confirmation, accurate mass data of alkaloids by LC/FTICR-MS were obtained within 5 ppm and the GC/MS data for the trimethylsilyl alkaloids were also obtained. Among 33 alkaloids identified from this study, 13 alkaloids were reported for the first time in the investigated C. species.

CONCLUSIONS

The LC/ESI-MS/MS technique was effective in obtaining structural information and yielded diagnostic ions for diverse alkaloids. Based on the identified 33 alkaloids, marker compounds were suggested for the three C. species with different geographic origins. This study may also be useful for elucidating unknown alkaloids in herbal medicines.

Fragmentation investigation of seven arylnaphthalide lignans using liquid chromatography/tandem quadrupole time-of-flight mass spectrometry

RATIONALE

The combination of fragmentation patterns in positive and negative ion modes could be helpful in understanding the structural features of these arylnaphthalide lignans.

METHODS

Fragmentation patterns of seven arylnaphthalide lignans were investigated using liquid chromatography/tandem time-of-flight mass spectrometry, and their fragmentation pathways were comprehensively characterized.

RESULTS

In the positive ion mode, the cleavage of the C-1'-C-7' bond was the most characteristic fragmentation pattern of the lignans with both 2'-hydroxy and 4',5'-methylenedioxy groups on the B ring. Arylnaphthalide lignans containing a methylenedioxy group on the B ring could lose C(2)H(2)O(2) easily. The characteristic mass losses of 58 Da (C(2)H(2)O(2)) could indicate the presence of a methylenedioxy group on the B ring. In the negative ion mode, the type of substituents at C-7 could affect the cleavage pattern of the lactone ring.

CONCLUSIONS

In search for new compounds, and also in quality control, there is a need to have reliable methodology for the analysis of arylnaphthalide lignans. These results should be useful in the analysis of natural products with similar substructures from Chinese herbs in the future.

High-performance liquid chromatography-electrospray ionization-mass spectrometry ligand fishing assay: a method for screening triplex DNA binders from natural plant extracts

A novel ligand fishing assay was established to screen triplex DNA binders from complicated samples by a combination of immobilization of triplex DNA on agarose beads and high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS). The biotinylated oligodeoxynucleotides were first bound to the streptavidin agarose beads and then incubated with the duplex DNA as the baits for ligand fishing. This assay was validated by the testing ligand library consisting of coralyne, ethidium bromide, vitexin, and formononetin. The binding affinities of ligands to target DNA were also obtained based on the calibration curves of ligands. Two components (berberine and palmatine) in the extract of Phellodendron chinense Schneid cortexes were fished out as triplex DNA binders by this assay, which indicated its feasibility for screening triplex DNA binders from complicated samples. This preliminary assay can be used for not only screening binders of triplex DNA from natural products extracts but also can obtain their binding affinity information.

Analysis of the Constituents in Rat Serum after Oral Administration of Fufang Zhenzhu Tiaozhi Capsule by UPLC-Q-TOF-MS/MS

A rapid and sensitive UPLC/Q-TOF-MS method has been established for analysis of the constituents in rat serum after oral administration of Fufang Zhenzhu Tiaozhi (FTZ) capsule, an effective compound prescription for treating hyperlipidemia in the clinic. The UPLC/MS information of samples was obtained first in FTZ preparation and FTZ-treated rat serum. Mass spectra were acquired in both negative and positive ion modes. Thirty-six constituents in rat serum after oral administration of FTZ were detected, including the alkaloids, ginsenosides, pentacyclic triterpenes, and their metabolites. These chemicals were identified based on the retention time and mass spectrometry data with those of authentic standards or comparison of the literatures reports. Twenty-seven prototype components originated from FTZ and nine were the metabolites of the FTZ constituents. These results shed light on the potential active constituents of the complex traditional Chinese medicinal formulas.

Isolation and structural elucidation of indole alkaloids from Geissospermum vellosii by mass spectrometry

Alkaloids from the stem bark of Geissospermum vellosii possess a variety of therapeutic properties including antimalarial activities, activity as a sexual stimulant and inhibition of the proliferation of HIV and herpes viruses. Methods currently used to isolate the active components from G. vellosii are time-consuming, labor intensive, and result in low recovery. In addition, there is a lack of sensitive and accurate analytical methods for the structural characterization and identification of alkaloid components in minor quantities. A combination of high performance counter-current chromatography and ESI tandem mass spectrometry (MS(n)) was established to isolate alkaloids from the stem bark of G. vellosii, and study their electrospray ionization mass spectrometry fragmentation behavior. Five indole alkaloids were successfully isolated and identified by nuclear magnetic resonance and mass spectrometry. The multi-stage tandem mass spectrometric data were used to study their fragmentation pattern and set a model for detailed structure characterization of related indole alkaloids. The presence of the even mass fragment ion suggestive of an odd number of nitrogen at m/z 144 corresponding to C(10)H(9)N was characteristic to indole alkaloids. The results of the experiments demonstrated that the combination of high performance counter current chromatography and ESI-MS(n) is a sensitive, selective and effective approach for rapid isolation and characterization of alkaloids from G. vellosii.

Comparative pharmacokinetics of dehydroevodiamine and coptisine in rat plasma after oral administration of single herbs and Zuojinwan prescription

Zuojinwan, which consists of Rhizoma coptidis-Evodia rutaecarpa powder (6:1,g/g), is a traditional Chinese medicine (TCM) prescription, clinically used for the treatment of gastro-intestinal disorders. This study compared the pharmacokinetics of dehydroevodiamine and coptisine, the main active ingredients in Zuojinwan, in rats administrated with whole prescription or single herbs. Multiple blood concentration peaks were observed in the mean plasma-concentration curves. The pharmacokinetic parameters were quite different between single herbs and Zuojinwan prescription. Moreover, the mean plasma concentration of dehydroevodiamine increased and the one of coptisine decreased after combining, which was in accord with the clinical principle of TCM.