Simultaneous characterization of quaternary alkaloids, 8-oxoprotoberberine alkaloids, and a steroid compound in Coscinium fenestratum by liquid chromatography hybrid ion trap time-of-flight mass spectrometry

An algorithm-driven intelligent mining and identification strategy for natural product mass spectrometry

Efficiently mining and identification of new compounds from the extensive MS/MS datasets of plant extracts poses a significant challenge due to the structural diversity and compositional complexity inherent in natural products (NPs). Various data post-processing techniques have been developed to simplify the interpretation of MS/MS data; however, they often suffer from limited specificity and precision. Meanwhile, structure annotation following data post-processing is particularly time-consuming. In this study, we introduced an innovative strategy named MS-SMART, which integrates three intelligent algorithms: automatic mining of diagnostic ions, rapid filtration of alkaloids from untargeted MS/MS data, and structural recommendations for filtered components. The feasibility of this approach for rapidly discovering novel compounds was demonstrated using berberine-type alkaloids as an example. Firstly, diagnostic ions were automatically extracted and validated using available reference data. Subsequently, berberine-type compounds were filtered from raw MS/MS data. Finally, the structures of the target components were recommended using building blocks derived from berberines reported in various plants. A total of 103, 198, 60, 80 and 51 berberines were efficiently identified in diverse families and genera, including Stephaniae Epigaeae Radix, Coptidis Rhizoma, Phellodendri Chinensis Cortex, Phellodendri Amurensis Cortex and Corydalis Decumbentis Rhizoma, with 99, 169, 50, 64 and 40 new compounds identified, respectively. Among these, 8, 14, 8, 7 and 12 berberines were confirmed by reference compounds. This strategy provides a new research paradigm for the rapid discovery and identification of different types of new compounds in complex samples.

Integrating network pharmacology and transcriptomics to study the potential mechanism of Jingzhi Niuhuang Jiedu tablet in rats with accumulation of heat in the lungs and stomach

ETHNOPHARMACOLOGICAL RELEVANCE

Accumulation of heat in the lungs and stomach (AHLS) is an important syndrome within the realm of traditional Chinese medicine (TCM). It is the fundamental reason behind numerous illnesses, including mouth ulcers, dermatological conditions, acne, and pharyngitis. Jingzhi Niuhuang Jiedu tablet (JN) serves as the representative prescription for treatment of AHLS clinically. However, the effective components and mechanism of JN's impact on AHLS remain unexplored.

AIM OF THE STUDY

The objective of this research was to analyze the effective components of JN and investigate the therapeutic effect and potential mechanism of JN on AHLS.

MATERIALS AND METHODS

The effective compounds of JN extract were analyzed and identified using UHPLC-Q-Exactive/HRMS. Utilizing network pharmacology to investigate JN's multi-target, multi-pathway process in treating AHLS. Subsequently, anti-inflammatory activities of JN extract were evaluated in the RAW264.7 cells stimulated by lipopolysaccharide (LPS). In addition, a rat AHLS model induced by LPS and dried ginger was established. Pathological changes in rat lung and stomach tissues observed by HE staining and Masson's trichrome staining. Additionally, the expression of TNF-α, IL-6, and IL-1β in bronchoalveolar lavage fluid (BALF) was identified through the ELISA assay. For a deeper understanding of how JN might affect AHLS, transcriptomics was utilized to examine differential genes and their underlying mechanisms. Concurrently, techniques like quantitative polymerase chain reaction (q-PCR), immunofluorescence, and western blotting (WB) were employed to confirm various mRNA and protein expression, including Il17ra, Il17re, IL-17A, IL-1β, IL-6, PPARγ, PGC1-α and UCP1.

RESULTS

We identified 178 potential effective components in the JN extract. Network pharmacology analysis showed that the 144 components in JN act on 200 key targets for the treatment of AHLS by suppressing inflammation, regulating energy metabolism, and gastric function. In addition, JN suppressed the LPS-stimulated generation of NO, TNF-α, IL-1β, and IL-6 in RAW264.7 cells. And JN treatment effectively alleviated lung and stomach injury and reduced inflammation in rats. Analysis of RNA-seq from lung tissues revealed JN's substantial control over crucial genes in the IL-17 signaling pathway, including Il1b and Il17ra. Likewise, RNA sequencing of stomach tissues revealed that JN markedly decreased crucial genes in the Thermogenesis pathway, including Ppargc1a and Ppara. Additional experimental findings confirmed that treatment with JN significantly reduced the expression levels of mRNA (Il17ra, Il17re, Il1b, Ppargc1a and Ucp1), and the expression levels of protein (IL-17A, IL-1β, IL-6, PPARγ, PGC1-α and UCP1).

CONCLUSION

This study not only analyzes the effective components of JN but also reveals that JN could effectively ameliorate AHLS by inhibiting IL-17 signaling pathway and Thermogenesis pathway, which provides evidence for subsequent clinical studies and drug development.

A novel Vestitain A from the ripe fruits of Embelia vestita Roxb

A new compound, vestitain A (1), together with 11 known compounds were isolated from the ripe fruits of Embelia vestita Roxb., among them compounds 5,10-12 were isolated from this plant for the first time. Their structures were elucidated and characterized by detailed spectroscopic analysis. Further, the isolated new compound 1 was evaluated for its hypoglycemic effects in vivo. Our research showed that compound 1 could decrease the fasting blood glucose (FBG) by approximately 36.31% in diabetic rats at the high dose (800 mg/kg). By the Morris Water Maze experiments, we found that compound 1 had the effect of intervention on social behavior in diabetic rats, which might provide a reference basis for its development and utilization as a potential hypoglycemic drug.

Carboxylic Acid-Enabled Vinylene Transfer Reaction by Co(III) Catalyst: Scope and Applications to the Five-Step Total Synthesis of Protoberberine Alkaloids Containing Free Hydroxyl Group without Protection

A Co(III)-catalyzed vinylene transfer reaction enabled by carboxylic acid is presented. This redox-neutral transformation tolerates various functional groups, including free hydroxyl groups, and features practicality. Five-step routes based on the vinylene transfer reaction and Heck annulation have been devised to the total synthesis of 8-oxodehydrodiscretamine and 2-demethyl-oxypalmatine without the protection of the free hydroxyl functionality.

Intestines-erythrocytes-mediated bio-disposition deciphers the hypolipidemic effect of berberine from Rhizoma Coptidis: A neglected insight

ETHNOPHARMACOLOGICAL RELEVANCE

Rhizoma Coptidis (RC), the dried rhizome of Coptis Chinensis Franch., can dispel dampness and heat within the body and has been traditionally used for the treatment of cardiovascular disease (CVD)-associated problems including hyperlipidemia in China. Berberine (BBR) is the main active component of RC, which has been shown to possess significant therapeutic potential. However, only 0.14% of BBR is metabolized in the liver, and the extremely low bioavailability (<1%) and blood concentration of BBR in experimental and clinical settings is insufficient to achieve the effects as observed under in vitro conditions, which imposes challenges to explain its excellent pharmacological actions. Intense efforts are currently being devoted to defining its specific pharmacological molecular targets, while the exploration from the perspective of its pharmacokinetic disposition has rarely been reported to date, which could hardly make a comprehensive understanding of its hypolipidemic enigma.

AIM OF THE STUDY

This study made a pioneering endeavor to unveil the hypolipidemic mechanism of BBR from RC focusing on its unique intestines-erythrocytes-mediated bio-disposition.

MATERIALS AND METHODS

The fate of BBR in intestines and erythrocytes was probed by a rapid and sensitive LC/MS-IT-TOF method. To analyze the disposition of BBR, a reliable HPLC method was subsequently developed and validated for simultaneous determination of BBR and its key active metabolite oxyberberine (OBB) in whole blood, tissues, and excreta. Meanwhile, the enterohepatic circulation (BDC) of BBR and OBB was verified by bile duct catheterization rats. Finally, lipid overloading models of L02 and HepG2 cells were employed to probe the lipid-lowering activity of BBR and OBB at in vivo concentration.

RESULTS

The results showed that BBR underwent biotransformation in both intestines and erythrocytes, and converted into the major metabolite oxyberberine (OBB). The AUC_0-t ratio of total BBR to OBB was approximately 2:1 after oral administration. Besides, the AUC_0-t ratio of bound BBR to its unbound counterpart was 4.6:1, and this ratio of OBB was 2.5:1, indicative of abundant binding-type form in the blood. Liver dominated over other organs in tissue distribution. BBR was excreted in bile, while the excretion of OBB in feces was significantly higher than that in bile. Furthermore, the bimodal phenomenon of both BBR and OBB disappeared in BDC rats and the AUC_0-t was significantly lower than that in the sham-operated control rats. Interestingly, OBB significantly decreased triglycerides and cholesterol levels in lipid overloading models of L02 and HepG2 cells at in vivo-like concentration, which was superior to the prodrug BBR.

CONCLUSIONS

Cumulatively, BBR underwent unique extrahepatic metabolism and disposition into OBB by virtue of intestines and erythrocytes. BBR and OBB were mainly presented and transported in the protein-bound form within the circulating erythrocytes, potentially resulting in hepatocyte targeting accompanied by obvious enterohepatic circulation. The unique extrahepatic disposition of BBR via intestines and erythrocytes conceivably contributed enormously to its hypolipidemic effect. OBB was the important material basis for the hypolipidemic effect of BBR and RC.

Comprehensive chemical profiling and quantitative analysis of ethnicYi medicine Miao-Fu-Zhi-Tong granules using UHPLC-MS/MS

Developing analytical methods for the chemical components of natural medicines remains a challenge due to its diversity and complexity. Miao-Fu-Zhi-Tong (MFZT) granules, an ethnic Yi herbal prescription, comprises 10 herbs and has been clinically applied for gouty arthritis (GA) therapy. Herein, a series of chemical profiling strategies including in-house library matching, molecular networking and MS/MS fragmentation behavior validation based on ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) were developed for qualitative analysis of MFZT granules. A total of 207 compounds were identified or characterized in which several rare guanidines were discovered and profiled into alkyl substituted or cyclic subtypes. Moreover, network pharmacology analysis indicated that MFZT's anti-gout mechanism was mostly associated with the nuclear factor kappa-B (NF-κB) signaling, nucleotide oligomerization domain (NOD)-like signaling and rheumatoid arthritis pathways, along with the synergistic effect of 84 potential active compounds. In addition, a quantitative analytical method was developed to simultaneously determine the 29 potential effective components. Among them, berberine, pellodendrine, 3-feruloylquinic acid, neoastilbin, isoacteoside and chlorogenic acid derivatives at higher concentrations were considered as the chemical markers for quality control. These findings provide a holistic chemical basis for MFZT granules and will support the development of effective analytical methods for the herbal formulas of natural medicines.

Effect of Gut Microbiota on the Metabolism of Chemical Constituents of Berberis kansuensis Extract Based on UHPLC-Orbitrap-MS Technique

The dried stem bark of Berberis kansuensis is a commonly used Tibetan herbal medicine for the treatment of diabetes. Its main chemical components are alkaloids, such as berberine, magnoflorine and jatrorrhizine. However, the role of gut microbiota in the in vivo metabolism of these chemical components has not been fully elucidated. In this study, an ultra-high performance liquid chromatography method coupled with Orbitrap mass spectrometry (UHPLC-Orbitrap-MS) technology was applied to detect and identify prototype components and metabolites in rat intestinal contents and serum samples after oral administration of a B. kansuensis extract. A total of 16 prototype components and 40 metabolites were identified. The primary metabolic pathways of the chemical components from B. kansuensis extract were demethylation, desaturation, deglycosylation, reduction, hydroxylation, and other conjugation reactions including sulfation, glucuronidation, glycosidation, and methylation. By comparing the differences of metabolites between diabetic and pseudo-germ-free diabetic rats, we found that the metabolic transformation of some chemical components in B. kansuensis extract such as bufotenin, ferulic acid 4-O-β-D-glucopyranoside, magnoflorine, and 8-oxyberberine, was affected by the gut microbiota. The results revealed that the gut microbiota can affect the metabolic transformation of chemical constituents in B. kansuensis extract. These findings can enhance our understanding of the active ingredients of B. kansuensis extract and the key role of the gut microbiota on them.

In Vitro and In Silico Evaluation of Cholinesterase Inhibition by Alkaloids Obtained from Branches of Abuta panurensis Eichler

Alkaloids are natural products known as ethnobotanicals that have attracted increasing attention due to a wide range of their pharmacological properties. In this study, cholinesterase inhibitors were obtained from branches of Abuta panurensis Eichler (Menispermaceae), an endemic species from the Amazonian rainforest. Five alkaloids were isolated, and their structure was elucidated by a combination of 1D and 2D 1H and 13C NMR spectroscopy, HPLC-MS, and high-resolution MS: Lindoldhamine isomer m/z 569.2674 (1), stepharine m/z 298.1461 (2), palmatine m/z 352.1616 (3), 5-N-methylmaytenine m/z 420.2669 (4) and the N-trans-feruloyltyramine m/z 314.1404 (5). The compounds 1, 3, and 5 were isolated from A. panurensis for the first time. Interaction of the above-mentioned alkaloids with acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes was investigated in silico by molecular docking and molecular dynamics. The molecules under investigation were able to bind effectively with the active sites of the AChE and BChE enzymes. The compounds 1–4 demonstrated in vitro an inhibitory effect on acetylcholinesterase with IC50 values in the range of 19.55 µM to 61.24 µM. The data obtained in silico corroborate the results of AChE enzyme inhibition.

Comprehensive characterization of polyacetylenes and diterpenes from the underground parts of Solidago altissima L. and their contribution to the overall allelopathic activity

Solidago altissima L. (Asteraceae), a perennial plant native to North America, is considered one of the most invasive weeds in Asia and Europe. The successful invasion of S. altissima is possibly due to its allelopathic effect along with high seed productivity and strong vegetative propagation through rhizomes. Herein, to understand the invasion of S. altissima via the allelopathic effect, we isolated and characterized known and undescribed compounds from the underground parts of S. altissima and evaluated their contribution to the overall allelopathic activity of the plant. NMR spectroscopy and LC-MS analyses clarified the chemical structure of ten specialized metabolites including three undescribed compounds, i.e., (4Z, 8Z)-10-tigloyloxy matricaria lactone, (4Z, 8Z)-10-angeloyloxy matricaria lactone, and (2Z, 8Z)-10-methacryloyloxy matricaria ester. The evaluation of the content and allelopathic ability of each compound showed that cis-dehydromatricaria ester contributes to the allelopathic activities of the S. altissima extract.

A comparative investigation of the interaction and pharmacokinetics of hemoglobin with berberine and its oxymetabolite

Berberine (BBR), isolated from Coptis chinensis, is one type of isoquinoline alkaloids. BBR exerts numerous of bioactivities but the plasma concentration is really low. In our previous study, a new oxymetabolite (OBB) has been discovered and showed superior anti-inflammatory effect comparing with BBR. The aim of this study is to investigate the interaction, metabolite and pharmacokinetics of BBR with hemoglobin. Sprague-Dawley rats were used to carry out the interaction, metabolite and pharmacokinetics of BBR and OBB in vivo. Fluorescence spectra were used to analyse the interaction in vitro. Results showed that OBB could be generated after intravenous injection or incubating with BBR in vitro and in vivo; Both BBR and OBB exerted much stronger binding interaction with hemoglobin than plasma and affect the conformation of bovine hemoglobin and change the fluorescence spectral properties; BBR and OBB were mainly presented and transported in the proteins-bound form. These results provide a new insight to understand the dynamic equilibrium of BBR and OBB within body from the perspective of new metabolic pathways.

Simultaneous Qualitative and Quantitative Evaluation of the Coptidis Rhizoma and Euodiae Fructus Herbal Pair by Using UHPLC-ESI-QTOF-MS and UHPLC-DAD

The herbal pair of Coptidis Rhizoma (CR) and Euodiae Fructus (EF) is a classical traditional Chinese medicine formula used for treating gastro-intestinal disorders. In this study, we established a systematic method for chemical profiling and quantification analysis of the major constituents in the CR-EF herbal pair. A method of ultra high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) for qualitative analysis was developed. Sixty-five compounds, including alkaloids, phenolics, and limonoids, were identified or tentatively assigned by comparison with reference standards or literature data. The UHPLC fingerprints of 19 batches of the CR-EF herbal pair samples were obtained and the reference fingerprint chromatograms were established. Furthermore, nine compounds among 24 common peaks of fingerprints were considered as marker components, which either had high contents or significant bioactivities, were applied to quality control of the CR-EF herbal pair by quantitative analysis. This UHPLC-DAD analysis method was validated by precision, linearity, repeatability, stability, recovery, and so on. The method was simple and sensitive, and thus reliable for quantitative and chemical fingerprint analysis for the quality evaluation and control of the CR-EF herbal pair and related traditional Chinese medicines.

Alkaloids of Abuta panurensis Eichler: In silico and in vitro study of acetylcholinesterase inhibition, cytotoxic and immunomodulatory activities

Natural products obtained from species of the genus Abuta (Menispermaceae) are known as ethnobotanicals that are attracting increasing attention due to a wide range of their pharmacological properties. In this study, the alkaloids stepharine and 5-N-methylmaytenine were first isolated from branches of Abuta panurensis Eichler, an endemic species from the Amazonian rainforest. Structure of the compounds was elucidated by a combination of 1D and 2D NMR spectroscopic and MS and HRMS spectrometric techniques. Interaction of the above-mentioned alkaloids with acetylcholinesterase enzyme and interleukins IL-6 and IL-8 was investigated in silico by molecular docking. The molecules under investigation were able to bind effectively with the active sites of the AChE enzyme, IL-6, and IL-8 showing affinity towards the proteins. Along with the theoretical study, acetylcholinesterase enzyme inhibition, cytotoxic, and immunomodulatory activity of the compounds were assessed by in vitro assays. The data obtained in silico corroborate the results of AChE enzyme inhibition, the IC50 values of 61.24μM for stepharine and 19.55μM for 5-N-methylmaytenine were found. The compounds showed cytotoxic activity against two tumor cell lines (K562 and U937) with IC50 values ranging from 11.77 μM to 28.48 μM. The in vitro assays revealed that both alkaloids were non-toxic to Vero and human PBMC cells. As for the immunomodulatory activity, both compounds inhibited the production of IL-6 at similar levels. Stepharine inhibited considerably the production of IL-8 in comparison to 5-N-methylmaytenine, which showed a dose dependent action (inhibitory at the IC50 dose, and stimulatory at the twofold IC50 one). Such a behavior may possibly be explained by different binding modes of the alkaloids to the interleukin structural fragments. Occurrence of the polyamine alkaloid 5-N-methylmaytenine was reported for the first time for the Menispermaceae family, as well as the presence of stepharine in A. panurensis.

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.

Differentiation, chemical profiles and quality evaluation of five medicinal Stephania species (Menispermaceae) through integrated DNA barcoding, HPLC-QTOF-MS/MS and UHPLC-DAD

Stephania species is one of the alkaloid-rich genus of the family Menispermaceae. Most plants of the genus Stephania possess medicinal value, whose main components are alkaloids. However, the non-medical species are often mistakenly used as herbs because of the difficulty in identification of the species. A systematic method which involved the combination of DNA barcoding, HPLC-QTOF-MS/MS and UHPLC was established for differentiation, chemical profiles and quality evaluation of medicinal Stephania species. Firstly, twenty batches of Stephania species samples were classified into five Stephania species by DNA barcoding. Secondly, 114 alkaloids including 22 tetrahydroprotoberberines, 13 protoberberines, 27 aporphines, 13 benzylisoquinolines, 12 hasubanans, 3 morphines and 24 other alkaloids were clearly or tentatively identified. Thirdly, thirteen representative components were simultaneously detected by UHPLC-DAD to characterize the differences of chemical compositions among five Stephania species. In conclusion, this method was comprehensive and effective for identification, chemical profiles and quality evaluation of medicinal Stephania species. It will provide a basis for holistic quality evaluation of medicinal Stephania species.

Palmatine: A review of pharmacological properties and pharmacokinetics

The aim of this review is to collect together the results of the numerous studies over the last two decades on the pharmacological properties of palmatine published in scientific databases like Scopus and PubMed, which are scattered across different publications. Palmatine, an isoquinoline alkaloid from the class of protoberberines, is a yellow compound present in the extracts from different representatives of Berberidaceae, Papaveraceae, Ranunculaceae, and Menispermaceae. It has been extensively used in traditional medicine of Asia in the treatment of jaundice, liver-related diseases, hypertension, inflammation, and dysentery. New findings describe its possible applications in the treatment of civilization diseases like central nervous system-related problems. This review intends to let this alkaloid come out from the shade of a more frequently described alkaloid: berberine. The toxicity, pharmacokinetics, and biological activities of this protoberberine alkaloid will be developed in this work.

Alkaloids from the stems and rhizomes of Sinomenium acutum from the Qinling Mountains, China

Thirteen undescribed alkaloids (sinotumines A-M), including five oxoisoaporphine, a benzo[h]quinoline, an aporphine, two protoberberine, two hasubanane, and two proaporphine alkaloids, and 50 known analogues were isolated from the 95% aqueous EtOH extract of the stems and rhizomes of Sinomenium acutum. The structures and absolute configurations of the isolates were elucidated on the basis of comprehensive analysis of 1D and 2D NMR, HRMS, single-crystal X-ray diffraction, and comparison of the experimental and calculated electronic circular dichroism (ECD) data. Sinotumine F, a rare benzo[h]quinoline alkaloid, was speculated as an oxidation product of the oxoisoaporphine alkaloid, and its putative biosynthetic pathway is proposed. Sinotumines L and M are the first samples of proaporphine-based heterodimers coupled with 1-heptanone and coniferol alcohol moiety, respectively. The T-cell suppression and NO inhibition effects of the isolates were evaluated.

Multi-component profiles through the blood-brain barrier in rat after oral administration of over-the-counter drug Keke capsule by ultra-performance liquid chromatography/quadrupole- time-of-flight MSE method

Keke capsule as a traditional Chinese medicine formulation is used to relieve cough, for analgesia and to reduce bronchial asthma. The multi-components are absorbed into the blood and brain after oral administration of Keke capsule, with no systematic investigation so far. A reliable and rapid UPLC-QTOF-MS^E combined with a data processing software platform was used to characterize the components of Keke capsule and simultaneously identify bioactive components in blood and brain tissues in rat after oral administration. Consequently, a total of 41 components of Keke capsule, including alkaloids, flavone, flavonols, triterpene, lignanoid, organic acids, glycosides and coumarin were identified. Twenty-one components were found in plasma, including 18 prototypes and three metabolites; 15 components were found in brain tissues, including 10 prototypes and five metabolites. Alkaloids and flavonoids in Keke capsule were the main components which were absorbed into blood. The main alkaloids of Keke capsule can pass through the blood-brain barrier and show different distribution tendencies in brain tissues. The main components of keke capsule was simultaneously analyzed by throughput analysis, and the corresponding bioactive components were examined by blood-brain barrier in the rat after oral administration of the capsule.

Liquid Chromatography Coupled with Linear Ion Trap Hybrid OrbitrapMass Spectrometry for Determination of Alkaloids in Sinomeniumacutum

The characterization of alkaloids is challenging because of the diversity of structures and the complicated fragmentation of collision induced structural dissociation in mass spectrometry. In this study, we analyzed the alkaloids in Sinomenium acutum (Thunb.) Rehderet Wil by high resolution mass spectrometry. Chromatographic separation was achieved on a Phenomenex Kinetex C18 (2.1 mm × 100 mm, 2.6 μm) column with a mobile phase consisting of acetonitrile and water (0.1% formic acid) under gradient elution. A total of 52 alkaloids were well separated and 45 of them were structurally characterized, including morphinans, aporphines, benzylisoquinolines, and protoberberines. Specially, mass spectrometric study of the morphinan alkaloids were explicitly investigated. Electrostatic potential plot from simulation was calculated for determination of protonation sites. Further fragmentation analysis suggested that the C₃H₇N, CH₄O, and H₂O elimination was displayed in MS² spectrum. These fragmentation pathways are universal for morphinan alkaloids having methoxy substituted cyclohexenone or cyclohexadienone moieties. Additionally, for nitrogen oxides, an ion-neutral complex intermediate is involved in the fragmentation process, generating additional oxygenated ions. All these results provided the universal rules of fragmentation used for detection of alkaloids, and will be expected to be highly useful for comprehensive study of multi-components in the herbal medicine analysis.

Recent (2000-2015) developments in the analysis of minor unknown natural products based on characteristic fragment information using LC-MS

Liquid chromatography-Mass Spectrometry (LC-MS) has been widely used in natural product analysis. Global detection and identification of nontargeted components are desirable in natural product research, for example, in quality control of Chinese herbal medicine. Nontargeted components analysis continues to expand to exciting life science application domains such as metabonomics. With this background, the present review summarizes recent developments in the analysis of minor unknown natural products using LC-MS and mainly focuses on the determination of the molecular formulae, selection of precursor ions, and characteristic fragmentation patterns of the known compounds. This review consists of three parts. Firstly, the methods used to determine unique molecular formula of unknown compounds such as accurate mass measurements, MSⁿ spectra, or relative isotopic abundance information, are introduced. Secondly, the methods improving signal-to-noise ratio of MS/MS spectra by manual-MS/MS or workflow targeting-only signals were elucidated; pure precursor ions can be selected by changing the precursor ion isolated window. Lastly, characteristic fragmentation patterns such as Retro-Diels-Alder (RDA), McLafferty rearrangements, "internal residue loss," and so on, occurring in the molecular ions of natural products are summarized. Classical application of characteristic fragmentation patterns in identifying unknown compounds in extracts and relevant fragmentation mechanisms are presented (RDA reactions occurring readily in the molecular ions of flavanones or isoflavanones, McLafferty-type fragmentation reactions of some natural products such as epipolythiodioxopiperazines; fragmentation by "internal residue loss" possibly involving ion-neutral complex intermediates). © 2016 Wiley Periodicals, Inc. Mass Spec Rev 37:202-216, 2018.

Tissue-specific metabolite profiling of benzylisoquinoline alkaloids in the root of Macleaya cordata by combining laser microdissection with ultra-high-performance liquid chromatography/tandem mass spectrometry

RATIONALE

Tissue-specific metabolite profiling helps to find trace alkaloids masked during organ analysis, which contributes to understanding the alkaloid biosynthetic pathways in vivo and evaluating the quality of medical plants by morphology. As Macleaya cordata contains diverse types of benzylisoquinoline alkaloids (BIAs), the alkaloid metabolite profiling was carried out on various tissues of the root.

METHODS

Laser microdissection with fluorescence detection was used to recognize and dissect different tissues from the root of M. cordata. Ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry was applied to analyze the trace alkaloids in tissues. These detected alkaloids were elucidated using their accurate molecular weights, MS/MS data, MS fragmentation patterns and the known biosynthetic pathways of BIAs. Finally, the distribution of alkaloids in dissected tissues and whole sections was mapped.

RESULTS

Forty-nine alkaloids were identified from five microdissected tissues, and 24 of them were detected for the first time in M. cordata. Some types of alkaloids occurred specifically in dissected tissues. More alkaloids were detected in the cork and xylem vascular bundles which emit strong fluorescence under fluorescence microscopy. Some of the screened alkaloids were intermediates in sanguinarine and chelerythrine biosynthetic pathways, and others were speculated to be involved in the new branches of biosynthetic pathways.

CONCLUSIONS

The integrated method is sensitive, specific and reliable for determining trace alkaloids, which is also a powerful tool for metabolite profiling of tissue-specific BIAs in situ. The present findings should contribute to a better understanding of the biosynthesis of BIAs in M. cordata root and provide scientific evidence for its quality evaluation based on morphological characteristics. Copyright © 2016 John Wiley & Sons, Ltd.

Diversity synthesis of tetrahydroprotoberberines glycosides by combined chemical and microbial catalysis

The present study was designed to construct the structurally diverse library of tetrahydroprotoberberines (THPBs) by combining the methods of chemical nonselective demethylation and microbial glycosylation. HPLC-MS/MS analyses tentatively identified 12 de-methylated and 9 glycosylated derivates of THPBs and 5 rarely oxidized glycosides of THPBs in the library. Through this effort, we achieved not only a variety of the THPBs and their glycosides but also tested the catalytic characteristics and capabilities of G. deliquescens NRRL 1086.

Distribution and Discrimination Study of Bioactive Compounds from Berberis species using HPLC-ESI-QTOF-MS/MS with Principle Component Analysis

Berberis species have been used extensively as raw material in various herbal medicines. In this work, a fast and sensitive method based on reversed-phase high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (HPLC-ESI-QTOF-MS/MS) was used to assist the distribution and discrimination study of bioactive compounds from Berberis species such as B. aristata, B. asiatica, B. chitria, B. jaeschkeana, B. koehneana, B. lyceum, B. petiolaris and B. pseudoumbellata. The HPLC separation was performed on a Thermo Betasil C8 column (250 mm x 4.5 mm, 5μ) using gradient elution with a mobile phase of 0.1% aqueous solution of formic acid (v/v) and acetonitrile. The high resolution (HR) and collision induced dissociation (CID) mass spectrometry experiments were conducted in order to provide molecular-mass information and MS/MS fragmentation patterns of the compounds for structural elucidation. A total of 59 compounds were tentatively identified and characterized including three acids, forty-one alkaloids and twelve flavonoids using seventeen reference standards for authentication. Principle component analysis (PCA) was also applied to discriminate eight Berberis species according to their plant parts i.e., leaf, stem and root. The highest total content of identified compounds was detected in the root of all the Berberis species wherein alkaloids were predominant.

Quantitative Determination of Betaine, Choline, Acetylcholine, and 20-Hydroxyecdysone Simultaneously from Atriplex Species by UHPLC-UV-MS

A simple, rapid, and sensitive UHPLC-UV-MS method was developed for the quantitative determination of betaine (1), choline (2), acetylcholine (3), and 20-hydroxyecdysone (4) from various species of Atriplex. The baseline separation of the four analytes was achieved on a reversed phase C18 column within nine minutes. The mobile phase was composed of 50 mM ammonium formate in 2% methanol-water containing 5 mM sodium dodecyl sulfate (pH = 8.2) and methanol with 0.01% ammonium hydroxide. The analytical method was validated for recovery, precision, limits of detection (LOD), and limits of quantification (LOQ). The developed method was applied for the characterization and quantitation of analytes from plant parts of different Atriplex species, including A. canescens, A. fruticulosa, A. fasciculata, A. semibaccata, and A. lentiformis. Compounds 1–4 were found in a range of 0.53–1.61%, detection under limit of quantification (DUL)-0.74, DUL-0.0038, and 0-0.10% ( w/w, mg in 100 mg plant material), respectively, in test samples. In leaf and fruit of A. canescens, a high content of 1, 2, and 4 were identified. The content of 1, 2, and 4 in A. canescens explains the potential implications of this native US plant for human health and nutrition. The result of this study provides a new method to analyze these phytoconstituents simultaneously in a mixture.

Cerasoidine, a Bis-aporphine Alkaloid Isolated from Polyalthia cerasoides during Screening for Wnt Signal Inhibitors

A new bis-aporphine alkaloid, cerasoidine (1), was isolated from the root extract of Polyalthia cerasoides together with the known bis-aporphine bidebiline E (2) during screening for compounds with Wnt signal inhibitory activities. The structure of cerasoidine (1) was established by X-ray analysis and shown by chiral HPLC analyses and electronic circular dichroism to be a 57:43 mixture of R(-)- and S(+)-atropisomers. Bidebiline E (2) exhibited inhibition of transcriptional activity of TCF/β-catenin with an IC50 value of 20.2 μM and was also found to inhibit Wnt signaling by decreasing nuclear β-catenin.

Analysis of phytochemical variations in dioecious Tinospora cordifolia stems using HPLC/QTOF MS/MS and UPLC/QqQLIT -MS/MS

INTRODUCTION

The stem of dioecious Tinospora cordifolia (Menispermaceae) is a commonly used traditional Ayurvedic medicine in India having several therapeutic properties.

OBJECTIVE

To develop and validate LC-MS methods for the identification and simultaneous quantitation of various secondary metabolites and to study metabolomic variations in the stem of male and female plants.

METHODS

Ethanolic extract of stems were analysed by HPLC/ESI-QTOF-MS/MS for rapid screening of bioactive phytochemicals. High resolution MS and MS/MS in positive ESI mode were used for structural investigation of secondary metabolites. An UPLC/ESI-QqQ(LIT) -MS/MS method in MRM mode was developed and validated for the simultaneous quantitation of five bioactive alkaloids.

RESULTS

Identification and characterisation of 36 metabolites including alkaloids, sesquiterpenes and phytoecdysteroids were performed using LC-MS and MS/MS techniques. The bioactive alkaloids such as jatrorrhizine, magnoflorine, isocorydine, palmatine and tetrahydropalmatine were successfully quantified in male and female plants. The mean abundances of magnoflorine jatrorrhizine, and oblongine were significantly (P < 0.05) higher in male plants while mean abundances of tetrahydropalmatine, norcoclaurine, and reticuline were significantly (P < 0.05) higher in female plants.

CONCLUSIONS

Phytochemicals in the stem of male and female Tinospora cordifolia showed significant qualitative and quantitative variations. LC-MS and MS/MS methods can be used to differentiate between male and female plants based on their chemical profiles and quantities of the marker bioactive alkaloids. This chemical composition difference was also evident during vegetative stage when there were no male and female flowers.

A Review of Traditional Medicinal Plants from Kachin State, Northern Myanmar

Medicinal plants are a vital source of medication in developing countries. In Kachin State, Northern Myanmar, the people have a long history of the use of traditional plants for medicinal purposes. This article deals with the 25 most used medicinal plants in Kachin State. They are: Drynaria fortunei, Tetrastigma serrulatum, Bauhinia championii, Goniothalamus cheliensis, Juglans regia, Houttuynia cordata, Osmanthus fragrans, Pothos chinensis, Tabemaemontana coronaria, Eryngium foetidum, Chloranthus spicatus, Peperomia pellucida, Zanthoxylum armatum, Polygonum fagopyrum, Cymbidium floribundum, Amomum kravanh, Coscinium fenestratum, Solanum nigrum, Gnetum parvifolium, Desmodium triquetum, Begonia augustinec, Mappianthus iodoides, Erycibe obtusifolia, Schefflera venulosa, Holarrhena antidysenterica. The different traditional applications, the known chemical constituents and medicinal properties are reported for each plant. The efficacy of several of these plants has been supported by some scientific evidence, while other plants have to be submitted to further investigations to prove the beneficial medicinal properties attributed to them.

Metabonomic Study of Biochemical Changes in Human Hair of Heroin Abusers by Liquid Chromatography Coupled with Ion Trap-Time of Flight Mass Spectrometry

Hair analysis is with the advantage of non-invasive collection and long surveillance window. The present study employed a sensitive and reliable liquid chromatography coupled with ion trap-time of flight mass spectrometry method to study the metabonomic characters in the hair of 58 heroin abusers and 72 non-heroin abusers. Results indicated that certain endogenous metabolites, such as sorbitol and cortisol, were accelerated, and the level of arachidonic acid, glutathione, linoleic acid, and myristic acid was decreased in hair of heroin abusers. The metabonomic study is helpful for further understanding of heroin addiction and clinical diagnosis.

Application of hydrostatic CCC-TLC-HPLC-ESI-TOF-MS for the bioguided fractionation of anticholinesterase alkaloids from Argemone mexicana L. roots

A rapid hydrostatic counter-current chromatography-thin-layer chromatography-electrospray-ionization time-of-flight mass spectrometry (CCC-TLC-ESI-TOF-MS) technique was established for use in seeking potent anti-Alzheimer's drugs among the acethylcholinesterase inhibitors in Argemone mexicana L. underground parts, with no need to isolate components in pure form. The dichloromethane extract from the roots of Mexican prickly poppy that was most rich in secondary metabolites was subjected to hydrostatic-CCC-based fractionation in descending mode, using a biphasic system composed of petroleum ether-ethyl acetate-methanol-water at the ratio of 1.5:3:2.1:2 (v/v). The obtained fractions were analyzed in a TLC-based AChE-inhibition "Fast Blue B" test. All active components in the fractions, including berberine, protopine, chelerithrine, sanguinarine, coptisine, palmatine, magnoflorine, and galanthamine, were identified in a direct TLC-HPLC-ESI-TOF-MS assay with high accuracy. This is the first time galanthamine has been reported in the extract of Mexican prickly poppy and the first time it has been identified in any member of the Papaveraceae family, in the significant quantity of 0.77%.

Rapid profiling and structural characterization of bioactive compounds and their distribution in different parts of Berberis petiolaris Wall. ex G. Don applying hyphenated mass spectrometric techniques

RATIONALE

Berberis petiolaris Wall. is a lesser known medicinal plant, belonging to the family Berberidaceae. The genus Berberis is known for many biological activities such as anti-microbial, anti-inflammatory and anti-diarrheal, etc. There are not many reports of the isolation of components from Berberis petiolaris. This study aims to seek identification, characterization and quantification of components.

METHODS

A method was developed for rapid screening of phytochemicals using high-pressure liquid chromatography hyphenated with quadrupole time-of-flight mass spectrometry (HPLC/ESI-QTOF-MS/MS). Suitable collision-induced dissociation mass spectrometry (CID-MS/MS) methods were developed for structural investigation of alkaloids, flavanoids and other classes of compounds using nine reference standards for authentication. Multiple reaction monitoring (MRM) methods were developed for quantitative study of five constituents using triple quadrupole-linear ion trap mass spectrometry (UPLC/QqLIT-MS/MS).

RESULTS

On the basis of HPLC retention behavior and fragmentation pathways obtained by high-resolution MS and MS/MS, 32 compounds were identified and characterized in different parts of Berberis petiolaris. Quantitative studies of chlorogenic acid, magnoflorine, jatrorrhizine, palmatine and berberine were also completed successfully.

CONCLUSIONS

Rapid and accurate HPLC/ESI-QTOF-MS/MS and UPLC/ESI-QqLIT-MS/MS methods were established for identification, characterization and quantification of phytochemicals in the ethanolic extract of Berberis petiolaris. These methods, therefore, can be used for studies on phytochemical variation in different parts of the plant. Principle components analysis (PCA) may be used for plant part discrimination.

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.

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.

Transcript and metabolite profiling in cell cultures of 18 plant species that produce benzylisoquinoline alkaloids

Benzylisoquinoline alkaloids (BIAs) are a large and diverse group of ~2500 specialized metabolites found predominantly in plants of the order Ranunculales. Research focused on BIA metabolism in a restricted number of plant species has identified many enzymes and cognate genes involved in the biosynthesis of compounds such as morphine, sanguinarine and berberine. However, the formation of most BIAs remains uncharacterized at the molecular biochemical level. Herein a compendium of sequence- and metabolite-profiling resources from 18 species of BIA-accumulating cell cultures was established, representing four related plant families. Our integrated approach consisted of the construction of EST libraries each containing approximately 3500 unigenes per species for a total of 58,787 unigenes. The EST libraries were manually triaged using known BIA-biosynthetic genes as queries to identify putative homologs with similar or potentially different functions. Sequence resources were analyzed in the context of the targeted metabolite profiles obtained for each cell culture using electrospray-ionization and collision-induced dissociation mass spectrometry. Fragmentation analysis was used for the identification or structural characterization coupled with the relative quantification of 72 BIAs, which establishes a key resource for future work on alkaloid biosynthesis. The metabolite profile obtained for each species provides a rational basis for the prediction of enzyme function in BIA metabolism. The metabolic frameworks assembled through the integration of transcript and metabolite profiles allow a comparison of BIA metabolism across several plant species and families. Taken together, these data represent an important tool for the discovery of BIA biosynthetic genes.

Synthesis of silver nanorods using Coscinium fenestratum extracts and its cytotoxic activity against Hep-2 cell line

Silver nanorod has attracted considerable interest due to its potential applications in display technologies, thermoelectric and electronic devices, optoelectronic devices and biomedicine. In this study, crystalline silver nanorods were successfully prepared from AgNO(3) using Coscinium fenestratum extract as a reducing agent. The products were characterized by UV-visible spectroscopy, FTIR (Fourier-transform IR) spectroscopy and SEM (scanning electron microscopy) analysis. Bundle-like nanostructures were observed by SEM analysis and the diameters of the nanorods were found to be in the range of 28.5-68.0 nm. The MTT assay results revealed that silver nanorod exhibit significant cytotoxic effect on HEp-2 cells.

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.

Comprehensive separation and analysis of alkaloids from Stephania yunnanensis by counter-current chromatography coupled with liquid chromatography tandem mass spectrometry analysis

The polar compounds such as alkaloid compounds are important bioactive components in traditional Chinese medicines. In present study, a comprehensive method for separation and analysis of polar compounds from the polar fraction of traditional Chinese medicine Stephania yunnanensis was established. Both the major components and minor components were analyzed by counter-current chromatography combined with liquid chromatography tandem mass spectrometry (LC-MS(n)). From 50 mg polar fraction of crude extract, 15.2mg corydine and 4.8 mg stepharine with purities over 90% were successfully separated via a polar solvent system n-butanol: methanol: water (4:1:5, v/v) with 10 mM NaOH as an additive in the lower phase, in one step operation. Their structures were further identified by 1H NMR and FTICR-MS. Besides, three minor components were identified by HPLC-MS(n) based on the fragmentation behavior of the purified compounds.

N-heterocyclic carbene-catalyzed [4 + 1] annulation of phthalaldehyde and imines

The diastereoselective synthesis of cis-2-amino-3-hydroxyindanones was realized by the N-heterocyclic carbene-catalyzed [4 + 1] annulation of phthalaldehyde and imines, which may involve a tandem aza-benzoin reaction and aldol reaction.

Recent advances on HPLC/MS in medicinal plant analysis

With gaining popularity of herbal remedies worldwide, the need of assuring safety and efficacy of these products increases as well. By nature they are complex matrices, comprising a multitude of compounds, which are prone to variation due to environmental factors and manufacturing conditions. Furthermore, many traditional preparations compose of multiple herbs, so that only highly selective, sensitive and versatile analytical techniques will be suitable for quality control purposes. By hyphenating high performance liquid chromatography and mass spectrometry (LC-MS) these high demands are fulfilled, providing the user with a multitude of technical options and applications. This review intends to reflect the impact of LC-MS for medicinal plant analysis focusing on most relevant reports published within the last five years. Commenced by introductory remarks to the different MS approaches most commonly used (e.g. ion trap and time of flight mass analyzers, fragmentation and ionization modes), respective LC-MS applications on the analysis of natural products in medicinal plants, commercial products and biological samples are presented. Methodological aspects like stationary and mobile phase selection or MS settings are discussed, and advantages or limitations of the described techniques are highlighted.