A capsule review of recent studies on the application of mass spectrometry in the analysis of Chinese medicinal herbs

The Content of Volatile Organic Compounds in Calypogeia suecica (Calypogeiaceae, Marchantiophyta) Confirms Genetic Differentiation of This Liverwort Species into Two Groups

Calypogeia is a genus of liverworts in the family Calypogeiaceae. The subject of this study was Calypogeia suecica. Samples of the liverwort Calypogeia suecica were collected from various places in southern Poland. A total of 25 samples were collected in 2021, and 25 samples were collected in 2022. Volatile organic compounds (VOCs) from liverworts were analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 107 compounds were detected, of which 38 compounds were identified. The identified compounds were dominated by compounds from the sesquiterpene group (up to 34.77%) and sesquiterpenoids (up to 48.24%). The tested samples of Calypogeia suecica also contained compounds belonging the aromatic classification (up to 5.46%), aliphatic hydrocarbons (up to 1.66%), and small amounts of monoterpenes (up to 0.17%) and monoterpenoids (up to 0.30%). Due to the observed differences in the composition of VOCs, the tested plant material was divided into two groups, in accordance with genetic diversity.

Comparative Analysis of Volatile Compounds in the Flower Buds of Three Panax Species Using Fast Gas Chromatography Electronic Nose, Headspace-Gas Chromatography-Ion Mobility Spectrometry, and Headspace Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry Coupled with Multivariate Statistical Analysis

The flower buds of three Panax species (PGF: P. ginseng; PQF: P. quinquefolius; PNF: P. notoginseng) widely consumed as health tea are easily confused in market circulation. We aimed to develop a green, fast, and easy analysis strategy to distinguish PGF, PQF, and PNF. In this work, fast gas chromatography electronic nose (fast GC e-nose), headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS), and headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) were utilized to comprehensively analyze the volatile organic components (VOCs) of three flowers. Meanwhile, a principal component analysis (PCA) and heatmap were applied to distinguish the VOCs identified in PGF, PQF, and PNF. A random forest (RF) analysis was used to screen key factors affecting the discrimination. As a result, 39, 68, and 78 VOCs were identified in three flowers using fast GC e-nose, HS-GC-IMS, and HS-SPME-GC-MS. Nine VOCs were selected as potential chemical markers based on a model of RF for distinguishing these three species. Conclusively, a complete VOC analysis strategy was created to provide a methodological reference for the rapid, simple, and environmentally friendly detection and identification of food products (tea, oil, honey, etc.) and herbs with flavor characteristics and to provide a basis for further specification of their quality and base sources.

Characterization of effective phytochemicals in traditional Chinese medicine by mass spectrometry

Traditional Chinese medicines (TCMs) have been widely used in clinical and healthcare applications around the world. The characterization of the phytochemical components in TCMs is very important for studying the therapeutic mechanism of TCMs. In the analysis process, sample preparation and instrument analysis are key steps to improve analysis performance and accuracy. In recent years, chromatography combined with mass spectrometry (MS) has been widely used for the separation and detection of trace components in complex TCM samples. This article reviews various sample preparation techniques and chromatography-MS techniques, including the application of gas chromatography-MS and liquid chromatography-MS and other MS techniques in the characterization of phytochemicals in TCM materials and Chinese medicine products. This article also describes a new ambient ionization MS method for rapid and high-throughput analysis of TCM components.

Integrating diverse plant bioactive ingredients with cyclodextrins to fabricate functional films for food application: a critical review

The popularity of plant bioactive ingredients has become increasingly apparent in the food industry. However, these plant bioactive ingredients have many deficiencies, including low water solubility, poor stability, and unacceptable odor. Cyclodextrins (CDs), as cyclic molecules, have been extensively studied as superb vehicles of plant bioactive ingredients. These CD inclusion compounds could be added into various film matrices to fabricate bioactive food packaging materials. Therefore, in the present review, we summarized the extraction methods of plant bioactive ingredients, the addition of these CD inclusion compounds into thin-film materials, and their applications in food packaging. Furthermore, the release model and mechanism of active film materials based on various plant bioactive ingredients with CDs were highlighted. Finally, the current challenges and new opportunities based on these film materials have been discussed.

Multi-omics Comparative Analysis of Streptomyces Mutants Obtained by Iterative Atmosphere and Room-Temperature Plasma Mutagenesis

Sponges, the most primitive multicellular animals, contain a large number of unique microbial communities. Sponge-associated microorganisms, particularly actinomyces, have the potential to produce diverse active natural products. However, a large number of silent secondary metabolic gene clusters have failed to be revived under laboratory culture conditions. In this study, iterative atmospheric room-temperature plasma. (ARTP) mutagenesis coupled with multi-omics conjoint analysis was adopted to activate the inactive wild Streptomyces strain. The desirable exposure time employed in this study was 75 s to obtain the appropriate lethality rate (94%) and mutation positive rate (40.94%). After three iterations of ARTP mutagenesis, the proportion of mutants exhibiting antibacterial activities significantly increased by 75%. Transcriptome analysis further demonstrated that the differential gene expression levels of encoding type I lasso peptide aborycin had a significant upward trend in active mutants compared with wild-type strains, which was confirmed by LC-MS results with a relative molecular mass of 1082.43 ([M + 2H]²⁺ at m/z = 2164.86). Moreover, metabolome comparative analysis of the mutant and wild-type strains showed that four spectra or mass peaks presented obvious differences in terms of the total ion count or extracting ion current profiles with each peak corresponding to a specific compound exhibiting moderate antibacterial activity against Gram-positive indicators. Taken together, our data suggest that the ARTP treatment method coupled with multi-omics profiling analysis could be used to estimate the valid active molecules of metabolites from microbial crudes without requiring a time-consuming isolation process.

Systematic identification of compounds in Macleaya microcarpa by high-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry combined with mass spectral fragmentation behavior of Macleaya alkaloids

RATIONALE

Macleaya microcarpa (Maxim.) Fedde belongs to the genus Macleaya of the Papaveraceae family. Benzylisoquinoline alkaloids (BIAs) are considered the main bioactive constituents of M. microcarpa.

METHODS

Using high-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry (HPLC/QTOFMS/MS) we identified BIAs in the aerial parts of M. microcarpa in the early flowering stage. Target profiling and identification of BIAs in the extracted samples from the fresh aerial parts of M. microcarpa were exclusively based on a personal, accurate, mass database of known compounds and the mass spectral fragmentation behavior of Macleaya alkaloids.

RESULTS

A total of 97 alkaloids, comprising 7 benzyltetrahydroisoquinolines, 1aporphine, 9 tetraprotoberberines, 3 protoberberines, 2 N-methyltetrahydroprotoberberines, 4 protopines, 47 dihydrobenzophenanthridines, and 24 benzophenanthridines, were identified from the fresh aerial parts of M. microcarpa, and 77 of these were detected for the first time in M. microcarpa. In addition, some of the screened alkaloids were related to the biosynthetic pathways of sanguinarine and chelerythrine.

CONCLUSIONS

The integrated method is sensitive and reliable for screening and identifying trace or ultra-trace isoquinoline alkaloids and has contributed to a better understanding of BIAs in the fresh aerial parts of M. microcarpa.

Natural Phyto-Bioactive Compounds for the Treatment of Type 2 Diabetes: Inflammation as a Target

Diabetes is a metabolic, endocrine disorder which is characterized by hyperglycemia and glucose intolerance due to insulin resistance. Extensive research has confirmed that inflammation is closely involved in the pathogenesis of diabetes and its complications. Patients with diabetes display typical features of an inflammatory process characterized by the presence of cytokines, immune cell infiltration, impaired function and tissue destruction. Numerous anti-diabetic drugs are often prescribed to diabetic patients, to reduce the risk of diabetes through modulation of inflammation. However, those anti-diabetic drugs are often not successful as a result of side effects; therefore, researchers are searching for efficient natural therapeutic targets with less or no side effects. Natural products' derived bioactive molecules have been proven to improve insulin resistance and associated complications through suppression of inflammatory signaling pathways. In this review article, we described the extraction, isolation and identification of bioactive compounds and its molecular mechanisms in the prevention of diabetes associated complications.

Characterization of the Principal Constituents of Danning Tablets, a Chinese Formula Consisting of Seven Herbs, by an UPLC-DAD-MS/MS Approach

Danning Tablets are a traditional Chinese formula showing broad clinical applications in hepatobiliary diseases and containing a diversity of bioactive chemicals. However, the chemical profiling of the formula, which serves as the material foundation of its efficacy, is really a big challenge as Danning Tablets consist of seven herbs from different origins. An ultra-performance liquid chromatography coupled to diode array detection and electrospray ionization mass spectrometry (UPLC-DAD-ESI-MS/MS) approach was developed to characterize the principal polyphenol constituents in the formula. As a result, a total of 32 constituents, including 14 anthraquinones and their glucosides, four anthrones, two naphthalene glycosides, two stilbenes and 10 flavonoids were identified based on their retention time, UV absorption and MS/MS fragmentation patterns. The sources of these compounds were also illustrated. Most of the bioactive anthraquinone derivatives were found in Rhei Radix et Rhizoma or Polygoni Cuspidati Rhizoma et Radix, which are the Emperor drugs in the formula for its clinic usage. These findings indicate the merit of using this integrated UPLC-DAD-ESI-MS/MS approach to rapidly illustrate the chemical foundation of complex formulas. The present study will facilitate the quality control of Danning Tablet formulas as well as the individual herbs.

Identification of the chemical constituents of Chinese medicine Yi-Xin-Shu capsule by molecular feature orientated precursor ion selection and tandem mass spectrometry structure elucidation

The incomplete identification of the chemical components of traditional Chinese medicinal formula has been one of the bottlenecks in the modernization of traditional Chinese medicine. Tandem mass spectrometry has been widely used for the identification of chemical substances. Current automatic tandem mass spectrometry acquisition, where precursor ions were selected according to their signal intensity, encounters a drawback in chemical substances identification when samples contain many overlapping signals. Compounds in minor or trace amounts could not be identified because most tandem mass spectrometry information was lost. Herein, a molecular feature orientated precursor ion selection and tandem mass spectrometry structure elucidation method for complex Chinese medicine chemical constituent analysis was developed. The precursor ions were selected according to their two-dimensional characteristics of retention times and mass-to-charge ratio ranges from herbal compounds, so that all precursor ions from herbal compounds were included and more minor chemical constituents in Chinese medicine were identified. Compared to the conventional automatic tandem mass spectrometry setups, the approach is novel and can overcome the drawback for chemical substances identification. As an example, 276 compounds from the Chinese Medicine of Yi-Xin-Shu capsule were identified.

Fallopia japonica, a Natural Modulator, Can Overcome Multidrug Resistance in Cancer Cells

Resistance of cancer cells to chemotherapy is controlled by the decrease of intracellular drug accumulation, increase of detoxification, and diminished propensity of cancer cells to undergo apoptosis. ATP-binding cassette (ABC) membrane transporters with intracellular metabolic enzymes contribute to the complex and unresolved phenomenon of multidrug resistance (MDR). Natural products as alternative medicine have great potential to discover new MDR inhibitors with diverse modes of action. In this study, we characterized several extracts of traditional Chinese medicine (TCM) plants (N = 16) for their interaction with ABC transporters, cytochrome P3A4 (CYP3A4), and glutathione-S-transferase (GST) activities and their cytotoxic effect on different cancer cell lines. Fallopia japonica (FJ) (Polygonaceae) shows potent inhibitory effect on CYP3A4 P-glycoprotein activity about 1.8-fold when compared to verapamil as positive control. FJ shows significant inhibitory effect (39.81%) compared with the known inhibitor ketoconazole and 100 μg/mL inhibited GST activity to 14 μmol/min/mL. FJ shows moderate cytotoxicity in human Caco-2, HepG-2, and HeLa cell lines; IC₅₀ values were 630.98, 198.80, and 317.37 µg/mL, respectively. LC-ESI-MS were used to identify and quantify the most abundant compounds, emodin, polydatin, and resveratrol, in the most active extract of FJ. Here, we present the prospect of using Fallopia japonica as natural products to modulate the function of ABC drug transporters. We are conducting future study to evaluate the ability of the major active secondary metabolites of Fallopia japonica to modulate MDR and their impact in case of failure of chemotherapy.

Potential Antioxidant Anthraquinones Isolated fromRheum emodiShowing Nematicidal Activity againstMeloidogyne incognita

Antioxidant and nematicidal properties were evaluated forR. emodiextractives which are extracted by standardizing and adopting accelerated solvent extraction (ASE) method along with traditional Soxhlet extraction. The extracted material was separated using flash chromatography and the separation conditions and solvents were standardized for the extracted plant constituents. The purity was detected by using analytical reverse phase high pressure liquid chromatography (HPLC). LC-MS/MS detection in the direct infusion mode of the isolated, purified products afforded four anthraquinones, characterized by their infrared spectra (IR) and1H spectra as chrysophanol, physcion, emodin, and aloe-emodin. Five antraquinone glucoside derivatives and piceatannol-3-O-β-d-glucopyranoside have also been detected from the extracted product. Duringin vitroevaluation the antioxidant potential of methanolic crude extract (CE1) was the highest, followed by ethyl acetate crude extract (CE2) and chloroform extract (CE3) in DPPH radical scavenging activity. The CE1 also demonstrated outstanding nematicidal activity as compared with other extracts, pure anthraquinones, and even positive control azadirachtin. The study conclusively demonstrated the antioxidant potential ofR. emodiextracts and also its ability in extenuating theMeloidogyne incognita(root-knot nematode). The bioassay results can be extrapolated to actual field condition and clinical studies.

A gDNA microarray for genotyping salvia species

Salvia is an important genus from the Lamiaceae with approximately 1,000 species. This genus is distributed globally and cultivated for ornamental, culinary, and medicinal uses. We report the construction of the first fingerprinting array for Salvia species enriched with polymorphic and divergent DNA sequences and demonstrate the potential of this array for fingerprinting several economically important members of this genus. In order to generate the Salvia subtracted diversity array (SDA) a suppression subtractive hybridization (SSH) was performed between a pool of Salvia species and a pool of angiosperms and non-angiosperms to selectively isolate Salvia-specific sequences. A total of 285-subtracted genomic DNA (gDNA) fragments were amplified and arrayed. DNA fingerprints were obtained for fifteen Salvia genotypes including three that were not part of the original subtraction pool. Hierarchical cluster analysis indicated that the Salvia-specific SDA was capable of differentiating S. officinalis and S. miltiorrhiza from their closely related species and was also able to reveal genetic relationships consistent with geographical origins. In addition, this approach was capable of isolating highly polymorphic sequences from chloroplast and nuclear DNA without preliminary sequence information. Therefore, SDA is a powerful technique for fingerprinting non-model plants and for identifying new polymorphic loci that may be developed as potential molecular markers.

Validated rapid resolution LC-ESI-MS/MS method for simultaneous determination of five pulchinenosides from Pulsatilla chinensis (Bunge) Regel in rat plasma: application to pharmacokinetics and bioavailability studies

A simple, RRLC-ESI-MS/MS method was developed for the simultaneous determination of five oleanane pulchinenosides (B3, BD, B7, B10, and B11), in rat plasma following solid-phase extraction (SPE). Detection and quantitation were performed by MS/MS using electrospray ionization (ESI) and multiple reaction monitoring (MRM) mode. The MS/MS transitions of the triterpenoidal saponins: m/z 911.4→603.2, 749.4→471.3, 895.6→733.2, 733.5→455.3, and 579.3→371.1 were monitored for B3, BD, B7 and B10, B11 and internal standard (Forsythin), respectively. The method was validated in plasma samples, showed good linearity over a wide concentration range (r(2)>0.99), and with lower limits of quantification of 1.11 (B3), 0.751 (BD), 0.996 (B7), 0.415 (B10), and 0.332 (B11)ng/mL. The intra- and inter-day assay variability was less than 15% for all analytes. The mean extraction recoveries of analytes and IS from rats plasma were all more than 70.0%. The validation results demonstrate that this method is robust and specific. The validated method was successfully applied for the pharmacokinetic and bioavailability studies of the five pulchinenosides which are potentially active saponins present in P. chinensis saponins (PRS) extracts.

Introduction to hyphenated techniques and their applications in pharmacy

The hyphenated technique is developed from the coupling of a separation technique and an on-line spectroscopic detection technology. The remarkable improvements in hyphenated analytical methods over the last two decades have significantly broadened their applications in the analysis of biomaterials, especially natural products. In this article, recent advances in the applications of various hyphenated techniques, e.g., GC-MS, LC-MS, LC-FTIR, LC-NMR, CE-MS, etc. in the context of pre-isolation analyses of crude extracts or fraction from various natural sources, isolation and on-line detection of natural products, chemotaxonomic studies, chemical fingerprinting, quality control of herbal products, dereplication of natural products, and metabolomic studies are discussed with appropriate examples.

Tandem mass spectrometric analysis and density functional theory calculations on the fragmentation behavior of two tetradecanoylingenol regioisomers from Euphorbia wallichii

RATIONALE

Two structurally similar bioactive regioisomers, 3-O-tetradecanoylingenol and 20-O-tetradecanoylingenol, from Euphorbia wallichii presented quite different fragmentation behaviors. Revealing the related fragmentation pathways may improve the efficiency of characterization and identification of such type of compounds.

METHODS

The two regioisomers were subjected to collision-induced dissociation (CID) on Finnigan LCQ(DECA) and LTQ Orbitrap XL instruments. Based on the CID results, the possible fragmentation pathways were proposed and investigated with density functional theory (DFT) calculations.

RESULTS

Elimination of C(14)H(28)O(2) (tetradecanoic acid) for 3-O-tetradecanoylingenol and the sequential losses of C(4)H(8) (butylene) for 20-O-tetradecanoylingenol were observed in ESI-MS/MS, witnessed also by HR-ESI-MS/MS. The fragmentation pathways were proposed and verified by calculating the activation energy of their transition states by DFT calculations.

CONCLUSIONS

Based on the observations, fragmentation pathways for the two regioisomers were proposed and verified by calculating the energy of the reactants, products and the corresponding transition states using DFT. This report should have value in rapid identification of the derivatives of ingenol and other regioisomers in natural products.

Rapid differentiation of Panax ginseng and Panax quinquefolius by matrix-assisted laser desorption/ionization mass spectrometry

A matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS)-based method has been developed for rapid differentiation between Panax ginseng and Panax quinquefolius, two herbal medicines with similar chemical and physical properties but different therapeutic effects. This method required only a small quantity of samples, and the herbal medicines were analyzed by MALDI-MS either after a brief extraction step, or directly on the powder form or small pieces of raw samples. The acquired MALDI-MS spectra showed different patterns of ginsenosides and small chemical molecules between P. ginseng and P. quinquefolius, thus allowing unambiguous differentiation between the two Panax species based on the specific ions, intensity ratios of characteristic ions or principal component analysis. The approach could also be used to differentiate red ginseng or P. quinquefolius adulterated with P. ginseng from pure P. ginseng and pure Panax quinquefolium. The intensity ratios of characteristic ions in the MALDI-MS spectra showed high reproducibility and enabled quantitative determination of ginsenosides in the herbal samples and percentage of P. quinquefolius in the adulterated binary mixture. The method is simple, rapid, robust, and can be extended for analysis of other herbal medicines.

Silver (Ι)-assisted enantiomeric analysis of ginsenosides using electrospray ionization tandem mass spectrometry

For identification of ginsenoside enantiomers, electrospray ionization mass spectrometry (ESI-MS) was used to generate silver complexes of the type [ginsenoside + Ag](+). Collision induced dissociation of the silver-ginsenoside complexes produced fragment ions by dehydration, allowing differentiation of ginsenoside enantiomers by the intensity of [M + Ag - H(2)O](+) ion. In the meanwhile, an approach based on the distinct profiles of enantiomer-selective fragment ion intensity varied with collision energy was introduced to refine the identification and quantitation of ginsenoside enantiomers. Five pairs of enantiomeric ginsenosides were distinguished and quantified on the basis of the distribution of fragment ion [M + Ag - H(2)O](+). This method was also extended to the identification of other type of ginsenoside isomers such as ginsenoside Rb2 and Rb3. For demonstrating the practicability of this novel approach, it was utilized to analyze the molar ratio of 20-(S) and 20-(R) type enantiomeric ginsenosides in enantiomer mixture in red ginseng extract. The generation of characteristic fragment ion [M + Ag - H(2)O](+) likely results from the reduction of potential energy barrier of dehydration because of the catalysis of silver ion. The mechanism of enantiomer identification of ginsenosides was discussed from the aspects of computational modeling and internal energy.

Nebulizing conditions of pneumatic electrospray ionization significantly influence electrolyte effects on compound measurement

Composition of mobile phase can greatly influence the success of electrospray ionization (ESI)-interfaced liquid chromatography-mass spectrometry analysis. To investigate the relationship between formic-acid-based modification of mobile phase and ESI nebulizing conditions, an API 4000 ESI source and a TSQ Quantum one were compared under the same chromatographic conditions. Ginkgo terpene lactones and flavonols were measured in plasma, which involved using ascorbic acid to circumvent cross-interference between the analytes. ESI responses to using formic acid included changes in signal intensity, matrix effect, and upper limit of quantification. Significant disparities in the responses were observed between the two ESI sources, suggesting that the use of electrolyte modifier in liquid chromatography mobile phase and the pneumatic nebulization for ESI should be properly balanced to accomplish optimal ESI-based analysis. The distribution of unpaired ions toward the surface of the initial droplet was assumed to be an important step in the pneumatic ESI process. When using the electrolyte in mobile phase, a too fast droplet reduction by rapid-heating-assisted pneumatic nebulization could negatively decrease the time available for the unpaired ions to migrate from droplet interior to its surface. Ascorbic acid was identified as a major interfering substance for the bioanalytical assay; the interference mechanism might be associated with hindering the unpaired analyte ions from distributing toward the droplet surface rather than outcompeting the analyte ions for the limited excess charge on droplets surface. The current work extends the knowledge base of pneumatic ESI, which has implication for optimal use of the ESI-interfaced liquid chromatography-mass spectrometry technique.

Hyphenated techniques and their applications in natural products analysis

A technique where a separation technique is coupled with an online spectroscopic detection technology is known as hyphenated technique, e.g., GC-MS, LC-PDA, LC-MS, LC-FTIR, LC-NMR, LC-NMR-MS, and CE-MS. Recent advances in hyphenated analytical techniques have remarkably widened their applications to the analysis of complex biomaterials, especially natural products. This chapter focuses on the applications of hyphenated techniques to pre-isolation and isolation of natural products, dereplication, online partial identification of compounds, chemotaxonomic studies, chemical finger-printing, quality control of herbal products, and metabolomic studies, and presents specific examples. However, a particular emphasis has been given on the hyphenated techniques that involve an LC as the separation tool.

Qualitative and quantitative analyses of flavonoids in Spirodela polyrrhiza by high-performance liquid chromatography coupled with mass spectrometry

INTRODUCTION

Spirodela polyrrhiza (L.) Schleid. is a traditional Chinese herbal medicine for the treatment of influenza. Despite its wide use in Chinese medicine, no report on quality control of this herb is available so far.

OBJECTIVE

To establish qualitative and quantitative analytical methods by high-performance liquid chromatography (HPLC) coupled with mass spectrometry (MS) for the quality control of S. polyrrhiza.

METHODOLOGY

The methanol extract of S. polyrrhiza was analysed by HPLC/ESI-MS(n). Flavonoids were identified by comparing with reference standards or according to their MS(n) (n = 2-4) fragmentation behaviours. Based on LC/MS data, a standardised HPLC fingerprint was established by analysing 15 batches of commercial herbal samples. Furthermore, quantitative analysis was conducted by determining five major flavonoids, namely luteolin 8-C-glucoside, apigenin 8-C-glucoside, luteolin 7-O-glucoside, apigenin 7-O-glucoside and luteolin.

RESULTS

A total of 18 flavonoids were identified by LC/MS, and 14 of them were reported from this herb for the first time. The HPLC fingerprints contained 10 common peaks, and could differentiate good quality batches from counterfeits. The total contents of five major flavonoids in S. polyrrhiza varied significantly from 4.28 to 19.87 mg/g.

CONCLUSION

Qualitative LC/MS and quantitative HPLC analytical methods were established for the comprehensive quality control of S. polyrrhiza.

Identification of indole alkaloids in Nauclea officinalis using high-performance liquid chromatography coupled with ion trap and time-of-flight mass spectrometry

Indole alkaloids from Nauclea officinalis (Pierra ex Pitard) Merr are prospective agents for inflammation- related diseases. To speed up the process of discovering such bioactive compounds from natural origins, a mass spectrometry-based method was developed to screen N. officinalis for the presence of indole alkaloids. First, representative alkaloids were purified from herbs and analyzed using an ion trap (IT) mass spectrometer. Multi-stage mass spectra (MS(n))were utilized to establish the characteristic fragmentation pathways of indole alkaloids. It was shown that their fragmentation behaviors were correlated with the degree of unsaturation on ring-D of such alkaloids: if there is a double bond between C-3 and C-14, no fragments of ring cleavage are observed; otherwise, a fragment ion after reverse Diels-Alder cleavage of ring-D is observed as the base peak in their tandem mass spectrometry data. Then, herbal extracts of N. officinalis were analyzed using a combination of high- performance liquid chromatography (HPLC)/IT and HPLC/time-of-flight (ToF) systems. The structures of suspected alkaloids were deduced based on the accurate mass information from ToF and MS(n) from IT. Finally, a total of 10 indole and one indolizidine alkaloids were identified or tentatively characterized in extracts of N. officinalis. This work has demonstrated that the combination of MS(n) and ToF-MS can be used for rapid identification of monoterpenoid indole alkaloids in N. officinalis.

Qingkailing injection attenuates apoptosis and neurologic deficits in a rat model of intracerebral hemorrhage

AIM OF THE STUDY

Traditional Chinese herb Angong Niuhuang Pill (AGNHP) is a famous preparation for neurological diseases; Qingkailing injection (QKL), an extract of AGNHP has similar clinical applications. This investigation was designed to further elucidate the neuroprotective effect of QKL on intracerebral hemorrhage (ICH).

MATERIALS AND METHODS

ICH was produced in adult Sprague-Dawley rats by injection of collagenase IV. Three incremental doses of QKL injection including low-(0.5 ml/kg), moderate-(1 ml/kg) and high-dosage (2 ml/kg) were administered twice, 3 and 12h following ICH. TUNEL and caspase-3 activity were measured at 1d after ICH, and apomorphine-induced rotation was evaluated at 1d, 7d, 14 d and 28 d.

RESULTS

Administration of high-dose QKL inhibited TUNEL positive cells (p<0.05) and caspase-3 activity (p<0.05) at 1d following ICH, and reduced apomorphine-induced rotation at 1d (p<0.01), 7d, 14 d and 28 d (p<0.05), compared with the controls. However, QKL in a low or moderate dose had no such effect.

CONCLUSION

QKL reduced brain damage of intracerebral hemorrhage through inhibiting apoptosis, which suggested a potential intervention for ICH patients.

Ginsenosides chemistry, biosynthesis, analysis, and potential health effects

Ginsenosides are a special group of triterpenoid saponins that can be classified into two groups by the skeleton of their aglycones, namely dammarane- and oleanane-type. Ginsenosides are found nearly exclusively in Panax species (ginseng) and up to now more than 150 naturally occurring ginsenosides have been isolated from roots, leaves/stems, fruits, and/or flower heads of ginseng. Ginsenosides have been the target of a lot of research as they are believed to be the main active principles behind the claims of ginsengs efficacy. The potential health effects of ginsenosides that are discussed in this chapter include anticarcinogenic, immunomodulatory, anti-inflammatory, antiallergic, antiatherosclerotic, antihypertensive, and antidiabetic effects as well as antistress activity and effects on the central nervous system. Ginsensoides can be metabolized in the stomach (acid hydrolysis) and in the gastrointestinal tract (bacterial hydrolysis) or transformed to other ginsenosides by drying and steaming of ginseng to more bioavailable and bioactive ginsenosides. The metabolization and transformation of intact ginsenosides, which seems to play an important role for their potential health effects, are discussed. Qualitative and quantitative analytical techniques for the analysis of ginsenosides are important in relation to quality control of ginseng products and plant material and for the determination of the effects of processing of plant material as well as for the determination of the metabolism and bioavailability of ginsenosides. Analytical techniques for the analysis of ginsenosides that are described in this chapter are thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC) combined with various detectors, gas chromatography (GC), colorimetry, enzyme immunoassays (EIA), capillary electrophoresis (CE), nuclear magnetic resonance (NMR) spectroscopy, and spectrophotometric methods.

Effect of tanshinone IIA on the noncovalent interaction between warfarin and human serum albumin studied by electrospray ionization mass spectrometry

Enhanced anticoagulation and/or even bleeding are often observed when patients on long-term warfarin (WAR) therapy consumed Danshen, a well-known medicinal herb in traditional Chinese medicine (TCM). This study demonstrates that altered WAR metabolism, arising from its interaction with the active components in Danshen, played a significant role in this curative effect. Mass spectrometric techniques including ESI-ITMS (electrospray ionization ion-trap mass spectrometry) and ESI-TOF (time-of-flight)-MS have been developed for the study of such drug-herb interactions. The experimental approach involved a detailed analysis and comparison of WAR metabolites in vivo from blood or urine of rats that had been orally administrated with WAR, either singly or together with the representative bioactive component of Danshen-lipid soluble TIIA (Tanshinon IIA), and a study of the interaction of human serum albumin (HSA), WAR, and water-soluble sodium tanshinone IIA sulfonate (STS) in vitro. Results demonstrate that TIIA accelerates the metabolic rate of WAR, whereas STS displaces WAR from the WAR-HSA complex, resulting in an increase of free WAR concentration in blood. It is suggested that the elevated level and enhanced metabolism of WAR is responsible for the over-anticoagulation effect observed.

Global detection and identification of nontarget components from herbal preparations by liquid chromatography hybrid ion trap time-of-flight mass spectrometry and a strategy

Although the current literature has recorded many reports of identifying components from herbal preparations, all of them were largely limited to target components. This paper provides a novel and generally applicable approach to identifying nontarget components from herbal preparations, based on the use of liquid chromatography ion trap time-of-flight mass spectrometry (LC/MS-IT-TOF). A simple program was originally developed for searching the common diagnostic ions from all experimentally generated ions. The components sharing the exact same ions (mass error < 5 mDa) were classified into a family. All families were then connected into a coherent network by the bridging components that are present in two or more families. With the benefit from such a network, it is feasible to sequentially characterize the structures of all diagnostic ions once a single component has been de novo identified. The structures of the diagnostic ions could then be used as "a priori" information for selecting the exact candidates containing the substructures of the corresponding diagnostic ions from the primary database hits. This strategy enables a nearly 7-fold narrowing of the database hits and thus substantially enhances the analytical efficiency and sharpness. With the use of such an approach, 43 out of 53 components incorporated into the network have been successfully identified from the test herbal preparation. For the rest, components failed to be identified using this approach; a complementary approach to screening by sequential loss of specific chemical groups, proposed from the accurate mass differences between fragments, was established to narrow the database hits. All of the 87 peaks detected have been successfully identified by combining the use of both approaches except failed to differentiate some isomers. The presently developed approach and methodology would be useful for the identifications of complicated nontarget components from various complex mixtures such as herbal preparations, biological, and environmental samples.

Comparative analysis on microbial and rat metabolism of ginsenoside Rb1 by high-performance liquid chromatography coupled with tandem mass spectrometry

Ginsenoside Rb1 is an active protopanaxadiol saponin from Panax species. In order to compare the similarities and differences of microbial and mammalian metabolisms of ginsenoside Rb1, the microbial transformation by Acremonium strictum and metabolism in rats were comparatively studied. Microbial transformation of ginsenoside Rb1 by Acremonium strictum AS 3.2058 resulted in the formation of eight metabolites. Ten metabolites (M1-M10) were detected from the in vivo study in rats and eight of them were identified as the same compounds as those obtained from microbial metabolism by liquid chromatography-tandem mass spectrometry analysis and comparison with reference standards obtained from microbial metabolism. Their structures were identified as ginsenoside Rd, gypenoside XVII, 20(S)-ginsenoside Rg3, 20(R)-ginsenoside Rg3, ginsenoside F2, compound K, 12beta-hydroxydammar-3-one-20(S)-O-beta-d-glucopyranoside, and 25-hydroxyl-(E)-20(22)-ene-ginsenoside Rg3, respectively. The structures of the additional two metabolites were tentatively characterized as 20(22),24-diene-ginsenoside Rg3 and 25-hydroxyginsenoside Rd by HPLC-MS/MS analysis. M7-M10 are the first four reported metabolites in vivo. The time course of rat metabolism of ginsenoside Rb1 was also investigated.

Fingerprint profile of Ginkgo biloba nutritional supplements by LC/ESI-MS/MS

Ginkgo biloba is one of the most popular herb nutrition supplements, with terpene lactones and flavonoids being the two major active components. A fingerprint profile method was developed using a capillary HPLC/MS method which can identify more than 70 components from the G. biloba product. The method allows the flavonoids and terpene lactones to be detected simultaneously and information of both the parent ion and its fragmentation can be obtained in just one HPLC/MS run. Targeted post-acquisition analysis allows mass spectrometric information regarding the identification of flavonoid components to be easily distinguished from other data, however the same approach for terpene lactones was less successful due to dimer formation and requires further development. The fingerprint profiles of five commercial G. biloba nutritional supplements were obtained and compared; variation of some components among the samples was observed and fortification could be detected. In the quality control analysis of the G. biloba product this method could be viewed as complementary to specific quantitative analysis of some bioactive components of the herb.

Biotransformation of isoeugenol to vanillin by a newly isolated Bacillus pumilus strain: Identification of major metabolites

A bacterial strain S-1 capable of transforming isoeugenol to vanillin was isolated. The strain was identified as Bacillus pumilus based on biochemical tests, cellular fatty acid composition, riboprint pattern and 16S rRNA gene sequence analyses. In the biotransformation of isoeugenol, vanillin was the main product. With the growing culture of B. pumilus S-1, 10g l(-1) isoeugenol was converted to 3.75g l(-1) vanillin in 150 h, with a molar yield of 40.5% that is the highest up to now. Dehydrodiisoeugenol, a dimer of isoeugenol, was separated by preparative thin layer chromatography and identified by gas chromatography-mass spectrometry. Based on the accurate masses obtained from gas chromatography-high resolution mass spectrometry, two key intermediates, isoeugenol-epoxide (IE) and isoeugenol-diol (ID), were identified by mass spectra interpretations. The biotransformation with resting cells showed that vanillin was oxidized to vanillic acid and then to protocatechuic acid before the aromatic ring was broken. These findings suggest that isoeugenol is degraded through an epoxide-diol pathway.

Characterization of environmentally friendly nicotine degradation by Pseudomonas putida biotype A strain S16

Nicotine and some related alkaloids in tobacco and tobacco wastes are harmful to health and the environment, and a major environmental requirement is to remove them from tobacco and tobacco wastes. In this study, an isolated strain, S16, identified as Pseudomonas putida biotype A, was used to investigate nicotine degradation. Possible intermediates were identified based on the results of NMR, Fourier-transform (FT)-IR and UV spectroscopy, GC-MS and high-resolution MS (HR-MS) analysis. The pathway of nicotine degradation in P. putida was proposed to be from nicotine to 2,5-dihydroxypyridine through the intermediates N-methylmyosmine, 2'-hydroxynicotine, pseudooxynicotine, 3-pyridinebutanal,C-oxo, 3-succinoylpyridine and 6-hydroxy-3-succinoylpyridine. N-Methylmyosmine, 2,5-dihydroxypyridine and succinic acid were detected and satisfactorily verified for the first time as intermediates of nicotine degradation. In addition, an alcohol compound, 1-butanone,4-hydroxy-1-(3-pyridinyl), was found to be a novel product of nicotine degradation. These findings provide new insights into the microbial metabolism of nicotine and the environmentally friendly route of nicotine degradation.

In vivo pharmacokinetic and metabolism studies of ginsenoside Rd

A high-performance liquid chromatography-electrospray ionisation-tandem mass spectrometry (LC-ESI-MS(n)) method has been developed to determine ginsenoside Rd in human plasma and to identify its metabolites in rat urine. The plasma and urine samples were pretreated by solid phase extraction (SPE) prior to analyses. In this work, gentiopicroside was used as the internal standard. The lower limit of quantification (LLOQ) for Rd in human plasma was 3 ng/ml. The average half-life time in plasma was detected as 19.29 h, when 10 mg of ginsenoside Rd was administrated intravenously to the volunteers. Seven metabolites including three oxygenated, two combined and two hydrolyzed components were identified in rat urine samples by using LC-MS and MS-MS, when ginsenoside Rd administered either orally or intravenously.

Characterization of phenolic compounds in the fruits of Forsythia suspensa by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry

Phenolic compounds are the major bioactive constituents of Forsythia suspensa, an important Chinese herbal medicine used for the treatment of various infectious diseases. Fragmentation behaviors of the phenolic compounds in F. suspensa were investigated by using a high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS(n)) method. For common phenylethanoid glycosides, the loss of the caffeoyl moiety was the first fragmentation step, then sequential losses of rhamnose, hexose and water were observed in further fragmentations. If a substituent group presented in the beta position, the fragmentation was triggered by initial loss of a substituent group to form structures such as suspensaside A. Then it underwent the common fragmentation pathways as mentioned above, or eliminated characteristic residues of masses 134 or 152 Da, respectively. The latter pathway is reported here for the first time. The fragmentation behaviors of furofuran lignans displayed a typical cleavage of the tetrahydrofuran ring. However, the presence of a hydroxyl group at C-1 led to the successive loss of 30 Da. Neutral loss of CO(2) and benzyl cleavage were characteristic for lignans with a 2,3-dibenzylbutyrolactone skeleton. A neutral loss of 30 Da was also observed in the fragmentation pattern of flavonols. These fragmentation rules were implemented to analyze phenolic compounds in the fruits of F. suspensa. A total of 51 compounds, including 24 phenylethanoid glycosides, 21 lignans and 6 flavonols, were identified or tentatively characterized based on their retention times, UV spectra and MS fragmentation patterns.