Phytochemical Analysis

Current research reports and chronological list of recent articles.

The international scientific journal Phytochemical Analysis is devoted to the publication of original articles concerning the development, improvement, validation and/or extension of application of analytical methodology in the plant sciences. The spectrum of coverage is broad, encompassing methods and techniques relevant to the detection (including bio-screening), extraction, separation, purification, identification and quantification of compounds in plant biochemistry, plant cellular and molecular biology, plant biotechnology, the food sciences, agriculture and horticulture

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Additional research articles see Current Chemistry Research Articles. Magazines with similar content (phytochemistry):

 - Phytochemistry.

 - Phytochemistry Letters.

 - Phytochemistry Reviews.

Phytochemical Analysis - Abstracts

An Enzyme-linked Immunosorbent Assay for Genistein 7-O-[α-rhamnopyranosyl-(16)]-β-glucopyranoside Determination in Derris scandens using a Polyclonal Antibody

Introduction Genistein 7-O-[α-rhamnopyranosyl-(16)]-β-glucopyranoside (GTG) is a major bioactive compound in Derris scandens. It is responsible for anti-inflammatory activity by inhibition of cyclooxygenase and lipoxygenase. There are many commercial products of D. scandens available in Thailand. Objective To develop an enzyme-linked immunosorbent assay (ELISA) for the quantitative analysis of GTG in plant material and derived products using a polyclonal antibody. Methods An immunogen was synthesised by conjugating GTG with a carrier protein. The polyclonal antibody against GTG (GTG-PAb) was produced in New Zealand white rabbits. The ELISA method was validated for specificity, sensitivity, accuracy, precision and correlation with HPLC. Results The polyclonal antibody was specific to GTG and genistin within the range of compounds tested. The GTG ELISA was applied in the range 0.04–10.00 μg/mL with a limit of detection of 0.03 μg/mL. The recovery of GTG in spiked Derris scandens extracts ranged from 100.7 to 107.0%, with a coefficient of variation less than 7.0%. The intra- and inter-assay variations were less than 5.0%. The ELISA showed a good correlation with HPLC-UV analysis for GTG determination in samples, with a coefficient of determination (r2) of 0.9880. Conclusion An ELISA was established for GTG determination in Derris scandens. The GTG-PAb can react with GTG and genistin, but genistin has not been found in the plant. Therefore, the ELISA can be used for high throughput quality control of GTG content in D. scandens and its products. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 20.07.2016

Metabolomic Fingerprinting of Romaneschi Globe Artichokes by NMR Spectroscopy and Multivariate Data Analysis

Introduction Globe artichoke (Cynara cardunculus L. var. scolymus L. Fiori) and cardoon (Cynara cardunculus L. var. altilis DC) are sources of nutraceuticals and bioactive compounds. Objectives To apply a NMR metabolomic fingerprinting approach to Cynara cardunculus heads to obtain simultaneous identification and quantitation of the major classes of organic compounds. Methodology The edible part of 14 Globe artichoke populations, belonging to the Romaneschi varietal group, were extracted to obtain apolar and polar organic extracts. The analysis was also extended to one species of cultivated cardoon for comparison. The 1H-NMR of the extracts allowed simultaneous identification of the bioactive metabolites whose quantitation have been obtained by spectral integration followed by principal component analysis (PCA). Results Apolar organic extracts were mainly based on highly unsaturated long chain lipids. Polar organic extracts contained organic acids, amino acids, sugars (mainly inulin), caffeoyl derivatives (mainly cynarin), flavonoids, and terpenes. The level of nutraceuticals was found to be highest in the Italian landraces Bianco di Pertosa zia E and Natalina while cardoon showed the lowest content of all metabolites thus confirming the genetic distance between artichokes and cardoon. Conclusion Metabolomic approach coupling NMR spectroscopy with multivariate data analysis allowed for a detailed metabolite profile of artichoke and cardoon varieties to be obtained. Relevant differences in the relative content of the metabolites were observed for the species analysed. This work is the first application of 1H-NMR with multivariate statistics to provide a metabolomic fingerprinting of Cynara scolymus. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 20.07.2016

Simultaneous Determination of Bioactive Monoterpene Indole Alkaloids in Ethanolic Extract of Seven Rauvolfia Species using UHPLC with Hybrid Triple Quadrupole Linear Ion Trap Mass Spectrometry

Introduction Rauvolfia serpentina is an endangered plant species due to its over-exploitation. It has highly commercial and economic importance due to the presence of bioactive monoterpene indole alkaloids (MIAs) such as ajmaline, yohimbine, ajmalicine, serpentine and reserpine. Objective To develop a validated, rapid, sensitive and selective ultra-high-performance liquid chromatography coupled with hybrid triple quadrupole-linear ion trap mass spectrometry (UHPLC-QqQLIT-MS/MS) method in the multiple reaction monitoring (MRM) mode for simultaneous determination of bioactive MIAs in ethanolic extract of seven Rauvolfia species and herbal formulations. Methods The separation of MIAs was achieved on an ACQUITY UPLC BEH™ C18 column (1.7 μm, 2.1 mm × 50 mm) using a gradient mobile phase (0.1% aqueous formic acid and acetonitrile) at flow rate 0.3 μL/min in 7 min. The validated method showed good linearity (r2 ≥ 0.9999), limit of detection (LOD) (0.06–0.15 ng/mL), limit of quantitation (LOQ) (0.18–0.44 ng/mL), precisions [intraday: relative standard deviation (RSD) ≤ 2.24%, interday: RSD ≤ 2.74%], stability (RSD ≤ 1.53%) and overall recovery (RSD ≤ 2.23%). Results The validated method was applied to quantitate MIAs. Root of Rauvolfia vomitoria showed a high content of ajmaline (48.43 mg/g), serpentine (87.77 mg/g) whereas high quantities of yohimbine (100.21 mg/g) and ajmalicine (120.51 mg/g) were detected in R. tetraphylla. High content of reserpine was detected in R. micrantha (35.18 mg/g) and R. serpentina (32.38 mg/g). Conclusion The encouraging results of this study may lead to easy selection of suitable Rauvolfia species according to the abundance of MIAs. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 20.07.2016

GC-MS and q-NMR based chemotaxonomic evaluation of two Leonurus species

Introduction The genus Leonurus L. (fam: Lamiaceae) is represented in Uzbekistan by two species, L. panzerioides Popov. and L. turkestanicus V. I. Krecz. & Kuprian, which are used to treat nervous disorders and also as sedative and hypotensive agents. Objectives To establish the taxonomic status of Leonurus panzerioides and L. turkestanicus based on their chemical constituents analysed by GC–MS and q-NMR. Materials and Methods Quantitative 1H-NMR (q-NMR) was used to identify and quantify known major components in the methanol extracts of these two species. Additionally, the chemical composition of the essential oils obtained from the aerial parts of these plants were analysed by GC–MS. Results The q-NMR analyses of Leonurus panzerioides and L. turkestanicus revealed the presence of 8-acetylharpagide, harpagide, leonurine and stachydrine as major components. Using the GC–MS method, overall 24 and 39 constituents were identified, respectively, from L. panzerioides and L. turkestanicus oils. The major constituents of the essential oil of L. panzerioides were eugenol (30.9%) and p-vinyl guaiacol (15.8%), whereas thymol (40.1%) and octen-3-ol (13.1%) were the principal compounds in the essential oil of L. turkestanicus. Conclusion The major components in Leonurus panzerioides and L. turkestanicus as identified by the GC–MS and q-NMR analyses, were similar to those present in other Leonurus species and thus provided chemotaxonomic evidence for the placement of these species under the genus Leonurus. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 20.07.2016

Supercritical Extraction of Scopoletin from Helichrysum italicum (Roth) G. Don Flowers

Introduction The increasing popularity of immortelle (Helichrysum italicum (Roth) G. Don) and its products, particularly in the cosmetic industry, is evident nowadays. This plant is a source of coumarins, especially scopoletin, which are highly soluble in supercritical CO2. Objective The objective of this study was to perform the supercritical CO2 extraction process of Helichrysum italicum flowers at different values of pressure and temperature and to optimise the extraction process using response surface methodology in terms of obtaining the highest extraction yield and yield of extracted scopoletin. Methodology Extraction was performed in a supercritical extraction system under different extraction conditions of pressure and temperature determined by central composite rotatable design. The mass of flowers in the extractor of 40 g, extraction time of 90 min and CO2 mass flow rate of 1.94 kg/h were kept constant during experiments. Antioxidant activity was determined using the DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging assay method. Scopoletin concentration was determined by HPLC. Results Changes in extraction conditions affect the extracting results remarkably. The greatest extraction yield (6.31%) and the highest yield of scopoletin (1.933 mg/100 g) were obtained under extraction conditions of 20 MPa and 40°C. Extracts have also proven to possess antioxidant activity (44.0–58.1% DPPH scavenging activity) influenced by both temperature and pressure applied within the investigated parameters. Conclusion The extraction conditions, especially pressure, exhibited significant influence on the extraction yield as well as the yield of extracted scopoletin and antioxidant activity of extracts. Copyright © 2016 John Wiley & Sons, Ltd. Supercritical CO2 extraction of H. italicum flowers at different values of pressure and temperature was performed in order to optimize the extraction process using response surface methodology in terms of getting higher extraction yield and yield of scopoletin. The greatest extraction yield and the highest yield of scopoletin were obtained under extraction conditions of 20 MPa and 40°C. Extracts have also proven to possess antioxidant activity influenced by both temperature and pressure applied within the investigated parameters.
Datum: 20.07.2016

Ultra-high Performance Liquid Chromatography with Photodiode Array and Chemiluminescence Detection for the Determination of Polyphenolic Antioxidants in Erigeron acris L. Extracts

Introduction The quality of herbs is directly related to the presence of polyphenolic antioxidants. This is the first report on the quantification of individual polyphenolic constituents of Erigeron acris L. Objective To develop a new method using ultra-high performance liquid chromatography with photodiode array and chemiluminescence (UHPLC-PDA-CL) detection for the separation and determination of polyphenols in Erigeron acris extracts. Methodology The methanolic extracts from leaves and inflorescences of Erigeron acris were prepared by ultrasound assisted extraction. The chromatographic separation was performed on C18 column packed with 1.7-μm particles. The post-column CL detection was based on the enhancing effect of polyphenols on the CL generated in manganese(IV)–hexametaphosphate–formaldehyde system. Results The UHPLC method allowed to separate polyphenols in a short running time (13 min), which was three times shorter compared with traditional HPLC. The CL detection was characterised by 6–48 times higher sensitivity and up to three times lower detection limits compared to PDA detection. Qualitative and quantitative differences were observed in polyphenolic composition of Erigeron acris extracts. The main components of leaves were scutellarin and chlorogenic acid, whereas in inflorescences quercetin 3-O-glucoside was predominant. Conclusion Coupling of UHPLC with CL detection has been developed for the first time. This advanced chromatographic technique coupled with sensitive CL detection is a powerful approach for the investigation of polyphenolic profiles in natural products. The shorter analysis time and diminished waste generation makes the UHPLC method more environmentally friendly and more cost-effective in comparison with conventional HPLC. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 20.07.2016

Comparison of Analytical Methods in Chemometric Fingerprinting of Metallicolous and Non-metallicolous Populations of Echium vulgare L.

Introduction Adverse environmental conditions usually change plant biochemical pathways resulting in accumulation or decreased content of both primary and secondary metabolites. The chemometric fingerprinting analysis proves to be a useful tool to reveal phytochemical differentiation between plants inhabiting heavy metal-contaminated and uncontaminated areas. Objective Development and assessment of four analytical techniques – high performance capillary electrophoresis (HPCE), thin-layer chromatography (TLC), mass spectrometry (MS), and Fourier transform infrared (FTIR) spectroscopy in chemometric fingerprinting of metallicolous and non-metallicolous populations of Echium vulgare L. Material and Methods – Twenty-one crude methanol extracts of shoot samples representing three populations of Echium vulgare L., two originating from highly metal polluted areas and one from an unpolluted area, were investigated using four analytical methods: HPCE, TLC, MS, and FTIR spectroscopy. Data pre-processing (denoising, background subtracting, horizontal alignment) followed by principal component analysis (PCA), hierarchical clustering analysis (HCA), and phytochemical difference index (DI) calculations facilitated exploration of the differences and similarities between the populations. Results Clear phytochemical divergence between metallicolous and non-metallicolous populations of Echium vulgare was found. The suitability of the analytical techniques for revealing phytochemical markers and discrimination of individuals originating from different populations differed and in general increased in the order: TLC < MS = HPCE < FTIR. Conclusion The chemometric methods applied were successful in discrimination between samples from polluted and unpolluted areas, showing a potential perspective for environmental quality control. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 20.07.2016

Profiling and Simultaneous Quantitative Determination of Anthocyanins in Wild Myrtus communis L. Berries from Different Geographical Areas in Sardinia and their Comparative Evaluation

Introduction Myrtus communis L. (Myrtaceae) is a self-seeded shrub, widespread in Sardinia, with anti-inflammatory, antiseptic, antimicrobial, hypoglycemic and balsamic properties. Its berries, employed for the production of sweet myrtle liqueur, are characterised by a high content of bioactive polyphenols, mainly anthocyanins. Anthocyanin composition is quite specific for vegetables/fruits and can be used as a fingerprint to determine the authenticity, geographical origin and quality of raw materials, products and extracts. Objective To rapidly analyse and determine anthocyanins in 17 samples of Myrtus communis berries by developing a platform based on the integration of UHPLC–MS/MS quantitative data and multivariate analysis with the aim of extracting the most information possible from the data. Methodology UHPLC-ESI-MS/MS methods, working in positive ion mode, were performed for the detection and determination of target compounds in multiple reaction monitoring (MRM) mode. Optimal chromatographic conditions were achieved using an XSelect HSS T3 column and a gradient elution with 0.1% formic acid in water and 0.1% formic acid in acetonitrile. Principal component analysis (PCA) was applied to the quantitative data to correlate and discriminate 17 geographical collections of Myrtus communis. Results The developed quantitative method was reliable, sensitive and specific and was successfully applied to the quantification of 17 anthocyanins. Peonidin-3-O-glucoside was the most abundant compound in all the extracts investigated. Conclusion The developed methodology allows the identification of quali-quantitative differences among M. communis samples and thus defines the quality and value of this raw material for marketed products. Moreover, the reported data have an immediate commercial value due to the current interest in developing antioxidant nutraceuticals from Mediterranean plants, including Sardinian Myrtus communis. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 20.07.2016

Pro-toxic 1,2-Dehydropyrrolizidine Alkaloid Esters, Including Unprecedented 10-Membered Macrocyclic Diesters, in the Medicinally-used Alafia cf. caudata and Amphineurion marginatum (Apocynaceae: Apocynoideae: Nerieae and Apocyneae)

Introduction Within the Apocynoideae (Apocynaceae) pro-toxic dehydropyrrolizidine alkaloids have been reported only in Echiteae. However, attraction of pyrrolizidine alkaloid-pharmacophagous insects suggested their presence in Alafia cf. caudata Stapf (Nerieae: Alafiinae) and Amphineurion marginatum (Roxb.) D.J. Middleton (Apocyneae: Amphineuriinae), both used as medicinal plants. Objective To confirm the presence of dehydropyrrolizidine alkaloids in Alafia cf. caudata and Amphineurion marginatum and identify their structures. Methods Methanol extracts of air-dried roots, stems and leaves of non-flowering plants were analysed using HPLC-ESI(+)MS and MS/MS or collision-induced dissociation MS in low and/or high resolution modes. Pyrrolizidine alkaloids were tentatively identified based on the mass spectrometry data. Solid phase extraction combined with semi-preparative HPLC were used to isolate major alkaloids. Structures were elucidated using NMR spectroscopy. Results Monoesters of retronecine with senecioic, hydroxysenecioic or syringic acids were identified in roots of Alafia cf. caudata. Two unprecedented 10-membered macrocyclic dehydropyrrolizidine alkaloid diesters were isolated from roots of Amphineurion marginatum. Pyrrolizidine alkaloids were detected in root and leaf material of Alafia cf. caudata at 0.34 and 0.01% dry weight (DW), and 0.13, 0.02 and 0.09% DW in root, leaf and stem material of Amphineurion marginatum. Conclusions The presence of pro-toxic dehydropyrrolizidine alkaloids suggests that medical preparations of these plants pose potential health risks to consumers. Dehydropyrrolizidine alkaloids are evidently more widespread in Apocynoideae than previously assumed, and it would seem rewarding to study other members of this family for the presence of pyrrolizidines, dehydropyrrolizidines and dihydropyrrolizines. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 19.07.2016

Rapid Detection and Characterisation of Triterpene Saponins from the Root of Pulsatilla chinensis (Bunge) Regel by HPLC-ESI-QTOF-MS/MS

Introduction Triterpene saponins are the major bioactive components in the root of Pulsatilla chinensis (Bunge) Regel (RPC), and have been reported to possess antitumor and immunological adjuvant activities. However, the isolation, purification and elucidation procedures of triterpene saponins from RPC are difficult and time consuming due to high polarity and structural similarity. Objectives To develop an analytical strategy for discovering and elucidating triterpene saponins in RPC. Methods Methanolic extract of RPC is analysed by high-performance liquid chromatography coupled to electrospray ionisation and quadrupole time-of-flight-mass spectrometry (HPLC-ESI-QTOF-MS/MS). The MS and MS/MS experiments are conducted using the negative-ionisation mode, in order to provide molecular-mass information and production spectra for the structural elucidation of compounds. Results Based on retention times, accurate mass and mass spectrometric fragmentation, 24 triterpene saponins are identified or tentatively elucidated from RPC, of which nine triterpene saponins were not reported previously. Conclusion The HPLC-ESI-QTOF-MS/MS could be employed as a rapid, effective technique to screen and identify triterpene saponins in RPC without tedious and time-consuming isolation of pure constituents. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 17.06.2016

Issue Information

No abstract is available for this article.
Datum: 17.06.2016

Facile Separation of 5-O-Galloylquinic Acid from Chinese Green Tea Extract using Mesoporous Zirconium Phosphate

Introduction 5-O-Galloylquinic acid from green tea and other plants is attracting increasing attention for its antioxidant and antileishmanial bioactivities. It is always isolated using a silica column, a Sephadex column and high-performance liquid chromatography (HPLC) methods, which are either laborious or instrument dependent. Objective To develop a new method to easily separate 5-O-galloylquinic acid. Methodology Mesoporous zirconium phosphate (m-ZrP) was prepared to conveniently separate 5-O-galloylquinic acid from Chinese green tea extract, and the target compound was easily obtained by simple steps of adsorption, washing and desorption. The effects of the green tea extraction conditions, extract concentrations, and m-ZrP adsorption/desorption dynamics on the 5-O-galloylquinic acid separation were evaluated. Results 5-O-Galloylquinic acid that was separated from a 70% ethanol extract of green tea was of moderate HPLC purity (92%) and recovery (88%), and an increased non-specific binding of epigallocatechin gallate (EGCG) on m-ZrP was observed in the diluted tea extract. The times for maximal adsorption of 5-O-galloylquinic acid in 70% ethanol extract and maximal desorption of 5-O-galloylquinic acid in 0.4% phosphoric acid solution were confirmed as 7 h and 5 h, respectively. Conclusion A facile method to separate 5-O-galloylquinic acid from Chinese green tea extract using m-ZrP was established. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 17.06.2016

Application of a Smartphone Metabolomics Platform to the Authentication of Schisandra sinensis

Introduction Herbal medicines have been used for a long time all around the world. Since the quality of herbal preparations depends on the source of herbal materials, there has been a strong need to develop methods to correctly identify the origin of materials. Objective To develop a smartphone metabolomics platform as a simpler and low-cost alternative for the identification of herbal material source. Methodology Schisandra sinensis extracts from Korea and China were prepared. The visible spectra of all samples were measured by a smartphone spectrometer platform. This platform included all the necessary measures built-in for the metabolomics research: data acquisition, processing, chemometric analysis and visualisation of the results. The result of the smartphone metabolomics platform was compared to that of NMR-based metabolomics, suggesting the feasibility of smartphone platform in metabolomics research. Results The smartphone metabolomics platform gave similar results to the NMR method, showing good separation between Korean and Chinese materials and correct predictability for all test samples. Conclusion With its accuracy and advantages of affordability, user-friendliness, and portability, the smartphone metabolomics platform could be applied to the authentication of other medicinal plants. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 17.06.2016

Antitrypanosomal Activity of a Novel Taccalonolide from the Tubers of Tacca leontopetaloides

Introduction Several taccalonolides with various bioactivities have been isolated from Tacca species but no studies to isolate taccalonolides with anti-trypanosomal activity from Tacca leontopetaloides have been reported. Objectives To analyse extracts of the roots of Tacca leontopetaloides, purify the extracts by column chromatography and identify isolated compounds by spectroscopic methods. The compounds and fractions will be tested for antitrypanosomal activity in vitro against Trypanosoma brucei brucei. Material and methods Dried roots or tubers of Tacca leontopetaloides, chromatographic separation and spectroscopic identification. Results A novel taccalonolide A propanoate and some known taccalonolides were isolated and their structures were determined by NMR and mass spectrometry Conclusion Several taccalonolides were isolated from Tacca leontopetaloides and were found to have in vitro antitrypanosomal activity against Trypanosoma brucei brucei and EC50 values for the isolated compounds were from 0.79 µg/mL. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 17.06.2016

Issue Information

No abstract is available for this article.
Datum: 17.06.2016

Direct Coupling of HPTLC with MALDI-TOF MS for Qualitative Detection of Flavonoids on Phytochemical Fingerprints

Introduction Thin layer chromatographic fingerprints of plant raw materials and extracts for food and pharma applications often focus on phenol carbonic acids and flavonoids. The visual detection and comparison of Rf values of applied reference substances only renders limited phytochemical information. Recently, direct coupling of TLC with MALDI-TOF MS has been successfully applied for analysis of biologically relevant compounds such as lipids. The mass analysis of low molecular weight TLC or HPTLC fingerprints of flavonoids has, to our knowledge, not yet been investigated. Objectives In this study, the feasibility of direct coupling of HPTLC with UV-MALDI-TOF MS for determination of molecular mass of the ubiquitously present flavonol glycoside, rutin, and flavone glycoside, luteolin-7-O-glucoside, as well as their corresponding aglycones, quercetin and luteolin, is demonstrated. Methodology HPTLC plate suitable for combination with a MALDI MS adapter was used for chromatographic separation of compounds of interest. After separation, the plate was sprayed with 2,5 dihydroxybenzoic acid as a MALDI matrix using an automated spraying device. After drying, the developed chromatograms were scanned by UV-MALDI-TOF MS in positive mode with a spatial resolution of 0.2 mm. Results All compounds studied were distinctly detected in MALDI-TOF mass spectra. This is particularly pertinent for the co-eluted aglycones luteolin and quercetin, which could not have been distinguished by the common visual HPTLC derivatisation and evaluation. Conclusion This study demonstrates the potential of MALDI-TOF MS for the analysis of low molecular weight fingerprints of flavonoids directly from their HPTLC chromatogram. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 17.06.2016

In situ Identification of Labile Precursor Compounds and their Short-lived Intermediates in Plants using in vivo Nanospray High-resolution Mass Spectrometry

Introduction Many secondary metabolites in plants are labile compounds which under environmental stress, are difficult to detect and track due to the lack of rapid in situ identification techniques, making plant metabolomics research difficult. Therefore, developing a reliable analytical method for rapid in situ identification of labile compounds and their short-lived intermediates in plants is of great importance. Objective To develop under atmospheric pressure, a rapid in situ method for effective identification of labile compounds and their short-lived intermediates in fresh plants. Methodology An in vivo nanospray high-resolution mass spectrometry (HR-MS) method was used for rapid capture of labile compounds and their short-lived intermediates in plants. A quartz capillary was partially inserted into fresh plant tissues, and the liquid flowed out through the capillary tube owing to the capillary effect. A high direct current (d.c.) voltage was applied to the plant to generate a spray of charged droplets from the tip of the capillary carrying bioactive molecules toward the inlet of mass spectrometer for full-scan and MS/MS analysis. Results Many labile compounds and short-lived intermediates were identified via this method: including glucosinolates and their short-lived intermediates (existing for only 10 s) in Raphanus sativus roots, alliin and its conversion intermediate (existing for 20 s) in Allium sativum and labile precursor compound chlorogenic acid in Malus pumila Mill. Conclusion The method is an effective approach for in situ identification of internal labile compounds and their short-lived intermediates in fresh plants and it can be used as an auxiliary tool to explore the degradation mechanisms of new labile plant compounds. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 17.06.2016

Identification of Alkaloids in Stephania hainanensis by Liquid Chromatography Coupled with Quadrupole Time-of-flight Mass Spectrometry

Introduction Plants in the genus Stephania can produce diverse bioactive alkaloids. Stephania hainanensis is a medicinal plant that contains effective alkaloids. However, only 10 alkaloids have been reported in this species. Objective To characterise the alkaloids in Stephania hainanensis using liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (LC-QTOF-MS/MS). Methods An LC-QTOF-MS/MS method was developed for structural characterisation of the alkaloids in Stephania hainanensis. The chromatographic separation was performed on a phenyl column with gradient elution, and the tandem mass spectra were obtained by using an electrospray ionisation (ESI) interface in positive ionisation mode. Compound identification was based on the exact masses, fragmentation pathways, retention behaviours and related botanical biogenesis. Results A total of 37 tetrahydroprotoberberine-, quaternary protoberberine-, aporphine-, proaporphine-, benzylisoquinoline- or bisbenzylisoquinoline-type alkaloids were identified or tentatively identified in a single LC run. Twenty-seven of these alkaloids, including the benzylisoquinoline-type of alkaloids, have not been previously reported in Stephania hainanensis. The possible fragmentation pathways of different types of alkaloids were proposed. Besides the general fragmentations, the characteristic losses of CH3N = CH2 were observed for the benzylisoquinoline and aporphine alkaloids with two methyl groups on the nitrogen. Conclusion The LC-QTOF-MS/MS method enabled profiling and rational, but tentative, identification of diverse alkaloids in Stephania hainanensis. The results obtained may be helpful for understanding the bioactivity of S. hainanensis and evaluating the quality of this plant. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 17.06.2016

Simultaneous Quantification of Seven Bioactive Flavonoids in Citri Reticulatae Pericarpium by Ultra-Fast Liquid Chromatography Coupled with Tandem Mass Spectrometry

Introduction Citri Reticulatae Pericarpium (CRP) is a commonly-used traditional Chinese medicine with flavonoids as the major bioactive components. Nevertheless, the contents of the flavonoids in CRP of different sources may significantly vary affecting their therapeutic effects. Thus, the setting up of a reliable and comprehensive quality assessment method for flavonoids in CRP is necessary. Objective To set up a rapid and sensitive ultra-fast liquid chromatography coupled with tandem mass spectrometry (UFLC-MS/MS) method for simultaneous quantification of seven bioactive flavonoids in CRP. Methods A UFLC-MS/MS method coupled to ultrasound-assisted extraction was developed for simultaneous separation and quantification of seven flavonoids including hesperidin, neohesperidin, naringin, narirutin, tangeretin, nobiletin and sinensetin in 16 batches of CRP samples from different sources in China. Results The established method showed good linearity for all analytes with correlation coefficient (R) over 0.9980, together with satisfactory accuracy, precision and reproducibility. Furthermore, the recoveries at the three spiked levels were higher than 89.71% with relative standard deviations (RSDs) lower than 5.19%. The results indicated that the contents of seven bioactive flavonoids in CRP varied significantly among different sources. Among the samples under study, hesperidin showed the highest contents in 16 samples ranged from 27.50 to 86.30 mg/g, the contents of hesperidin in CRP-15 and CRP-9 were 27.50 and 86.30 mg/g, respectively, while, the amount of narirutin was too low to be measured in some samples. Conclusion This study revealed that the developed UFLC-MS/MS method was simple, sensitive and reliable for simultaneous quantification of multi-components in CRP with potential perspective for quality control of complex matrices. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 17.06.2016

Myrosinase Compatible Simultaneous Determination of Glucosinolates and Allyl Isothiocyanate by Capillary Electrophoresis Micellar Electrokinetic Chromatography (CE-MEKC)

Introduction The functional food Cruciferous vegetables contain glucosinolates which are decomposed by the myrosinase enzyme upon tissue damage. The isothiocyanates are the most frequent decomposition products. Because of their various bioactivities, these compounds and the myrosinase is of high interest to many scientific fields. Objective Development of a capillary electrophoresis method capable of myrosinase-compatible, simultaneous quantification of glucosinolates and isothiocyanates. Methods Capillary electrochromatography parameters were optimised, followed by optimisation of a myrosinase-compatible derivatisation procedure for isothiocyanates. Vegetable extracts (Brussels sprouts, horseradish, radish and watercress) were tested for myrosinase activity, glucosinolate content and isothiocyanate conversion rate. Allyl isothiocyanate was quantified in some food products. Results The method allows quantification of sinigrin, gluonasturtiin and allyl isothiocyanate after myrosinase compatible derivatisation in-vial by mercaptoacetic acid. The chromatograhpic separation takes 2.5 min (short-end injection) or 15 min (long-end injection). For the tested vegetables, measured myrosinase activity was between 0.960–27.694 and 0.461–26.322 µmol/min/mg protein, glucosinolate content was between 0–2291.8 and 0–248.5 µg/g fresh weight for sinigrin and gluconastrutiin, respectively. The possible specificity of plants to different glucosinolates was also shown. Allyl isothiocyanate release rate was different in different vegetables (73.13 − 102.13%). The method could also be used for quantification of allyl isothiocyanate from food products. Conclusions The presented capillary electrophoresis method requires a minimal amount of sample and contains only a few sample preparation steps, and can be used in several applications (glucosinolate determination, myrosinase activity measurement, isothiocyanate release estimation). Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 17.06.2016

Chemotaxonomic Studies of Nine Gentianaceae Species from Western China Based on Liquid Chromatography Tandem Mass Spectrometry and Fourier Transform Infrared Spectroscopy

Introduction Gentianaceae species which widely occur all over the world are used as folk medicine and raw food material with bitter properties. Although comparative analysis on metabolites in several Gentianaceae species has been reported, metabolic similarities used for chemotaxonomic studies are not yet clear. Objective To systematically characterise the variations of holistic metabolome and characteristic metabolites (iridoid glycosides and phenols) in nine Gentianaceae species from western China. Methodology Fourier transform infrared (FT-IR) spectroscopy was applied to determine the variations of holistic metabolome. A targeted metabolic profiling using liquid chromatography with tandem mass spectrometry (LC–MS/MS) was established for determination of seven characteristic metabolites and identification of their derivatives. Both FT-IR and LC–MS/MS data were subjected to chemometrics analysis for exploring variations in iridoid glycosides and phenols within these species. Results Holistic metabolome in genera Gentiana and Swertia was largely different. Diversity of the biosynthetic pathway of iridoid glycosides was also observed in these species. Principal component analysis (PCA) showed a clear separation according to infrageneric classifications of genus Gentiana. Some secondary metabolites, such as mangiferin, rhodenthoside A-C, isoorientin, isovitexin, amarogentin, and swertianolin would serve as potential chemotaxonomic markers to differentiate Gentianaceae species. Furthermore, the accumulation of the six major metabolites seems to depend on geographical regions in Sect. Monopodiae and Sect. Cruciata. Conclusions The combination of LC–MS/MS and FT-IR would provide some potential evidence on chemotaxonomic studies of Gentianaceae. Copyright © 2016 John Wiley & Sons, Ltd.
Datum: 26.02.2016

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