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Phytochemical Analysis - Current Research Articles

Current research articles: Phytochemistry

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Phytochemical Analysis - published by Wiley

Phytochemical Analysis 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

Current articles of the journal:

In Situ Detection and Identification of Hesperidin Crystals in Satsuma Mandarin (Citrus unshiu) Peel Cells

Introduction Hesperidin, a flavonoid known to have important pharmacological effects, accumulates particularly in the peels of satsuma mandarin (Citrus unshiu). Although histochemical studies have suggested that hesperidin forms crystals in some tissues of the Rutaceae and Umbelliferae, there has been no rigorous in situ detection or identification of hesperidin crystals in C. unshiu. Objective To characterise the chemical component of the crystals found in C. unshiu peels using Raman microscopy. Methods Sections of C. unshiu peels were made. The distribution and morphology of crystals in the sections were analysed microscopically. Raman microscopy was used to detect hesperidin in the sections directly. Results The crystals were more abundant in immature peel and were observed particularly in areas surrounding vascular bundles, around the border between the flavedo and albedo layers and just below the epidermal cells. In the morphological analysis by scanning electron microscopy, needle-shaped crystals aggregated and formed clusters of spherical crystals. Spectra obtained by Raman microscopy of the crystals in the peel sections were consistent with those of the hesperidin standard. Conclusion This study showed the detailed distribution of crystals in C. unshiu peels and their main component was identified using Raman microscopy to be hesperidin for the first time. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 6 November 2014 | 10:18 am

Ultrahigh-performance Liquid Chromatography and Mass Spectrometry (UHPLC–LTQ/Orbitrap/MS/MS) Study of Phenolic Profile of Serbian Poplar Type Propolis

Introduction Propolis is a resinous natural substance collected by honeybees from different plant sources. Due to the presence of various phytochemicals, this bee-product exhibits numerous biological activities, including anti-bacterial, anti-viral, anti-inflammatory, anti-oxidant, immunostimulating and anti-tumour effects. As the chemical composition and biological activity of propolis depend on its botanical and geographical origin, searching for new bioactive substances in various types of propolis from unexplored regions is of great importance. Objective The aim of this study is the evaluation of the phenolic profile of poplar propolis samples in order to characterise Serbian propolis, to identify possible new constituents and to specify the phenolic components relevant for differentiation of poplar propolis samples into two subgroups through simultaneous analysis of poplar bud extracts. Methods Ethanolic extracts of propolis and poplar buds were comprehensively analysed using ultrahigh-performance liquid chromatography coupled with hybrid mass spectrometry, which combines the linear trap quadrupole and Orbitrap MS/MS mass analyser together with chemometric methods. Results Extensive fingerprint analysis of Serbian propolis was achieved for the first time. Seventy-five phenolic compounds were detected. Eight of them were identified in propolis for the first time. Pattern-recognition methods applied to the content of ten quantified phenolics verified the existence of two subgroups of propolis, with galangin, chrysin and pinocembrin as the most influential distinguishing factors. Conclusion The phenolic composition of the analysed propolis samples confirm their affiliation to the European poplar type propolis and the existence of two subgroups according to botanical origin. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 6 November 2014 | 10:17 am

Revealing Metabolomic Variations in Cortex Moutan from Different Root Parts using HPLC–MS method

Introduction The distribution of metabolites in the different root parts of Cortex Moutan (the root bark of Paeonia suffruticosa Andrews) is not well understood, therefore, scientific evidence is not available for quality assessment of Cortex Moutan. Objective To reveal metabolomic variations in Cortex Moutan in order to gain deeper insights to enable quality control. Methods Metabolomic variations in the different root parts of Cortex Moutan were characterised using high-performance liquid chromatography combined with mass spectrometry (HPLC–MS) and multivariate data analysis. The discriminating metabolites in different root parts were evaluated by the one-way analysis of variance and a fold change parameter. Results The metabolite profiles of Cortex Moutan were largely dominated by five primary and 41 secondary metabolites . Higher levels of malic acid, gallic acid and mudanoside-B were mainly observed in the second lateral roots, whereas dihydroxyacetophenone, benzoyloxypaeoniflorin, suffruticoside-A, kaempferol dihexoside, mudanpioside E and mudanpioside J accumulated in the first lateral and axial roots. The highest contents of paeonol, galloyloxypaeoniflorin and procyanidin B were detected in the axial roots. Accordingly, metabolite compositions of Cortex Moutan were found to vary among different root parts. Conclusion The axial roots have higher quality than the lateral roots in Cortex Moutan due to the accumulation of bioactive secondary metabolites associated with plant physiology. These findings provided important scientific evidence for grading Cortex Moutan on the general market. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 17 September 2014 | 1:41 pm

Comparison of Soxhlet, Accelerated Solvent and Supercritical Fluid Extraction Techniques for Volatile (GC–MS and GC/FID) and Phenolic Compounds (HPLC–ESI/MS/MS) from Lamiaceae Species

Introduction Plants from the Lamiaceae family have been known traditionally for their beneficial health-promoting properties, attributed to their anti-inflammatory, anaesthetic and anti-microbial effects. Objective The purposes of this study was to characterise the essential oils from four Lamiaceae plants by applying different extraction techniques. Methods Accelerated solvent (ASE), Soxhlet and supercritical fluid (SFE) extraction methods were compared for their efficiency in obtaining the essential oils from plants. The volatile compounds were identified by GC–MS and the main chemotype was quantified by GC with flame ionisation detection (FID). Phenolic compounds were identified and quantified by HPLC and electrospray ionisation (ESI) with MS/MS. Results The essential oils Mentha piperita (ct. menthol/menthone), Rosmarinus officinalis L. (ct. eucalyptol/camphor) and Origanum vulgare (ct. carvacrol/thymol), whereas Thymus vulgaris L. was found to be a pure chemotype (ct. thymol). All three extracts also contained six phenolic compounds. The highest extraction yields were achieved by the Soxhlet and ASE techniques, with M. piperita and R. officinalis L. producing the highest concentrations of rosmarinic and carnosic acids. Finally, it was observed that M. piperita and O. vulgare produced the highest total phenolic content, whereas R. officinalis L. and T. vulgaris L. produced the highest anti-oxidant activity. Conclusion The ASE and Soxhlet extraction techniques presented the highest yields of volatile and phenolic compounds, showing their suitability to characterise the chemical profile of aromatic plants. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 4 September 2014 | 4:07 pm

Enantiomeric Determination of Four Diastereoisomeric Oxyneolignans from Bambusa tuldoides Munro

Introduction Bambusa tuldoides Munro, a bamboo species, is used as a health food, dietary supplement and folk medicine in China, and produces lignans that can be used to supplement other natural sources. Objective To simultaneously separate eight stereoisomers of a particular type of oxyneolignan by chiral chromatography. Methods Ninety-five per cent ethanol extracts of B. tuldoides Munro were analysed using HPLC/UV with a chiral column. The structures and configurations of isolated compounds were elucidated using NMR and circular dichroism (CD). Results Four diastereoisomers were characterised and given the names oxyneolignans A, B, C and D. Furthermore, each oxyneolignan occurred as a pair of enantiomers. The oxyneolignans A–D consisted of the erythro-diastereoisomer of oxyneolignan at C7 and C8. Conclusion The chiral chromatography combined with the analysis techniques of NMR and CD reported here were reliable methods for discovering and separating the enantiomers. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 4 September 2014 | 1:56 pm

Identification and Characterisation of Phenolics from Ixora coccinea L. (Rubiaceae) by Liquid Chromatography Multi-stage Mass Spectrometry

Introduction Ixora coccinea L. leaves and stem are used in traditional Sudanese and Ayurvedic medicinal systems for the treatment of diarrhoea, fever, headache, skin diseases, eye trouble, wounds, sores and ulcers. Recent studies show that I. coccinea has anti-oxidant, anti-bacterial, anti-cancer, anti-inflammatory, analgaesic, anti-diarrhoeal, hepatoprotective, cardioprotective, anti-mutagenic, wound healing and anti-tumour activities. Ixora coccinea is a rich source of polyphenols such as proanthocyanidins, flavonoids, flavonoids glycosides and tannins. Objectives To develop a LC–MSn method for the identification and characterisation of phenolic compounds of I. coccinea L. leaves and stem. Methods Aqueous methanolic (70% methanol) extracts of I. coccinea leaves and stem were used for LC–MSn to ensure efficient extraction of phenolics. A C18 amide reverse-phase HPLC column allowed separation of the phenolic compounds, including different isomers. For the LC–MS measurements, negative ion mode was used in order to obtain better tandem mass spectra and high-resolution mass spectra. Results The phenolics were identified by their typical UV absorptions at 254, 280 and 320?nm. All the flavonol glycosides showed a neutral loss of the glycan part; hydroxycinnamates showed loss of the cinnamoyl/cinnamic acid part; while proanthocyanidins showed a Diels-Alder fragment in negative ion mode mass spectra. Conclusion It was possible to identify C-3 and C-7 flavonol glycosides by their order of elution and it was also possible to predict the glycosylation position in flavonol diglycosides from their tandem mass spectra. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 4 September 2014 | 12:37 pm

Purification of Active Myrosinase from Plants by Aqueous Two-Phase Counter-Current Chromatography

Introduction Myrosinase (thioglucoside glucohydrolase; E.C., is a plant enzyme of increasing interest and importance to the biomedical community. Myrosinase catalyses the formation of isothiocyanates such as sulforaphane (from broccoli) and 4-(?-l-rhamnopyranosyloxy)benzyl isothiocyanate (from moringa), which are potent inducers of the cytoprotective phase-2 response in humans, by hydrolysis of their abundant glucosinolate (?-thioglucoside N-hydroxysulphate) precursors. Objective To develop an aqueous two-phase counter-current chromatography (CCC) system for the rapid, three-step purification of catalytically active myrosinase. Methods A high-concentration potassium phosphate and polyethylene glycol biphasic aqueous two-phase system (ATPS) is used with a newly developed CCC configuration that utilises spiral-wound, flat-twisted tubing (with an ovoid cross-section). Results Making the initial crude plant extract directly in the ATPS and injecting only the lower phase permitted highly selective partitioning of the myrosinase complex before a short chromatography on a spiral disk CCC. Optimum phase retention and separation of myrosinase from other plant proteins afforded a 60-fold purification. Conclusion Catalytically active myrosinase is purified from 3-day broccoli sprouts, 7-day daikon sprouts, mustard seeds and the leaves of field-grown moringa trees, in a CCC system that is predictably scalable. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 7 August 2014 | 11:27 am

Advances in Isoflavone Profile Characterisation using Matrix Solid-phase Dispersion Coupled to HPLC/DAD in Medicago Species

Introduction Analytical methods used in phytochemistry analysis are limited by the sample preparation step, which should ideally be fast, accurate, ecofriendly and achievable using low quantities of the sample. Matrix solid-phase dispersion (MSPD) may be a good alternative for combining extraction and purification procedures, thereby reducing the indicated limitations. Objective Applying an MSPD extraction procedure coupled to high-performance liquid chromatography diode-array detection (HPLC/DAD) as an alternative methodology to evaluate isoflavone profiles. Methods Isoflavone profiles were determined for the leaves of nine species of Medicago in the late flower phenological stage (one or more nodes with 50% open flowers, no seed pods). Extraction was performed following MSPD, and isoflavone profiles were characterised using HPLC/DAD. The quantified amounts were compared with previous results in different species commonly recognised as good sources of isoflavones. Results Formononetin was the major isoflavone in most species, except M. polymorpha and M. truncatula. The isoflavone amounts were significantly different among the assayed species, with M. orbicularis and M. arabica as the major isoflavone sources, while M. rigidula presented the lowest contents. Furthermore, the detected differences allow electing the best species as a primary source of a specific isoflavone. Conclusion The MSPD allowed good extraction efficiency, reproducibility and recovery. Some of the species showed relevant isoflavone contents, even when compared with acknowledged plant sources such as soy or red clover. To the best of our knowledge the results presented are reported for the first time in these species. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 7 August 2014 | 10:59 am

Identification of Phenanthrene Derivatives in Aerides rosea (Orchidaceae) Using the Combined Systems HPLC–ESI–HRMS/MS and HPLC–DAD–MS–SPE–UV–NMR

Introduction In our continued efforts to contribute to the general knowledge on the chemical diversity of orchids, we have decided to focus our investigations on the Aeridinae subtribe. Following our previous phytochemical study of Vanda coerulea, which has led to the identification of phenanthrene derivatives, a closely related species, Aerides rosea Lodd. ex Lindl. & Paxton, was chosen for investigation. Objective To identify new secondary metabolites, and to avoid isolation of those already known, by means of the combined systems HPLC–DAD(diode-array detector) with high-resolution tandem mass spectrometry (HRMS/MS) and HPLC–DAD–MS–SPE(solid-phase extraction)–UV–NMR. Methods A dereplication strategy was developed using a HPLC–DAD–HRMS/MS targeted method and applied to fractions from A. rosea stem extract. Characterisation of unknown minor compounds was then performed using the combined HPLC–DAD–MS–SPE–UV–NMR system. Results The dereplication method allowed the characterisation of four compounds (gigantol, imbricatin, methoxycoelonin and coelonin), previously isolated from Vanda coerulea stem extract. The analyses of two fractions permitted the identification of five additional minor constituents including one phenanthropyran, two phenanthrene and two dihydrophenanthrene derivatives. The full set of NMR data of each compound was obtained from microgram quantities. Conclusion Nine secondary metabolites were characterised in A. rosea stems, utilising HPLC systems combined with high-resolution analytical systems. Two of them are newly described phenanthrene derivatives: aerosanthrene (5-methoxyphenanthrene-2,3,7-triol) and aerosin (3-methoxy-9,10-dihydro-2,5,7-phenanthrenetriol). Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 6 August 2014 | 2:40 pm

Qualitative and Spatial Metabolite Profiling of Lichens by a LC–MS Approach Combined With Optimised Extraction

Introduction Lichens are self-sustaining partnerships comprising fungi as shape-forming partners for their enclosed symbiotic algae. They produce a tremendous diversity of metabolites (1050 metabolites described so far). Objectives A comparison of metabolic profiles in nine lichen species belonging to three genera (Lichina, Collema and Roccella) by using an optimised extraction protocol, determination of the fragmentation pathway and the in situ localisation for major compounds in Roccella species. Methods Chemical analysis was performed using a complementary study combining a Taguchi experimental design with qualitative analysis by high-performance liquid chromatography coupled with mass spectrometry techniques. Results Optimal conditions to obtain the best total extraction yield were determined as follows: mortar grinding to a fine powder, two successive extractions, solid:liquid ratio (2:60) and 700 rpm stirring. Qualitative analysis of the metabolite profiling of these nine species extracted with the optimised method was corroborated using MS and MS/MS approaches. Nine main compounds were identified: 1 ?-orcinol, 2 orsellinic acid, 3 putative choline sulphate, 4 roccellic acid, 5 montagnetol, 6 lecanoric acid, 7 erythrin, 8 lepraric acid and 9 acetylportentol, and several other compounds were reported. Identification was performed using the m/z ratio, fragmentation pathway and/or after isolation by NMR analysis. The variation of the metabolite profile in differently organised parts of two Roccella species suggests a specific role of major compounds in developmental stages of this symbiotic association. Conclusion Metabolic profiles represent specific chemical species and depend on the extraction conditions, the kind of the photobiont partner and the in situ localisation of major compounds. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 6 August 2014 | 2:39 pm

Rapid Determination of Oligopeptides and Amino Acids in Soybean Protein Hydrolysates using High-Resolution Mass Spectrometry

Introduction Soybean protein hydrolysates (SPHs), especially oligopeptides, have shown a variety of functional properties, including immunomodulatory and anti-oxidant effects. Soybean protein hydrolysate products have been used as functional ingredients in food, sports nutrition or clinical nutrition. However, the mixture is mostly undefined due to its complex nature, containing peptides and minor amino acids as well as small proteins. Objectives To develop a specific and efficient method for the identification and structural characterisation of oligopeptides in SPHs, and to determine free amino acids in SPHs in the same analytical run, for evaluation of the chemical profile of SPH products. Methods Accurate mass spectrometry (MS) datasets of SPH samples were recorded on a high-performance liquid chromatography (HPLC) tandem high-resolution (HR) MS system. Potential oligopeptides were tentatively characterised based on their elemental compositions and ring double bond equivalent (RDBE) values, as well as HRMS/MS data. The analytical method to determine amino acids was evaluated in terms of linearity, precision, apparent recovery and limits of detection and quantitation. Results In total, 186 oligopeptides spanning the mass range of m/z 200–1500 and three major free amino acids could be determined in SPH samples in a single sample injection. Ninety-nine oligopeptides were tentatively characterised. The sensitive and specific instrumental performances also permitted the determination of 19 amino acids with a limit of quantitation of???0.1??g/mL. Conclusion The HPLC–HRMS technique has proven to be an advantageous tool for the rapid characterisation of oligopeptides and determination of amino acids in soybean protein hydrolysates. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 7 July 2014 | 6:28 am

Box–Behnken Design for Optimum Extraction of Biogenetic Chemicals from P. lanceolata with an Energy Audit (Thermal?×?Microwave?×?Acoustic): A Case Study of HPTLC Determination with Additional Specificity Using On-line/Off-line Coupling with DAD/NIR/ESI-MS

Introduction The genus Pluchea comprises about 80 species distributed worldwide, out of them, only Pluchea lanceolata (DC.) Oliv. & Hiern, is used extensively in the traditional system of India. No chromatographic method is available for its quality. Objectives To perform the energy audit for the extraction of biogenetic pentacyclic triterpene, its acetate and sterol from P. lanceolata utilising organic and four alternative solvents. Additionally to resolve the uncertainty of TLC determination, on-line/off-line coupling with a diode-array detector (DAD), and near-infrared (NIR) and electrospray ionisation (ESI) MS was introduced. Methods The extraction of taraxasterol (Tx), taraxasterol acetate (TxAc) and stigmasterol (St) from P. lanceolata was performed using three energy modes. The effects of different operating parameters were studied for optimum extraction yield using the design of experiments, that is, the central composite design and Box–Behnken design. In addition to the retention factor (Rf) and visible spectral matching, two additional optical spectroscopic techniques, that is, NIR and ESI-MS, were applied for extended specificity. Results The method was developed for Tx, TxAc and St determination using HPTLC at 645 nm. The optimum extraction yield of targeted compounds was found to be higher with organic solvents than eco-friendly surfactants. The pulse ultrasonic assisted extraction (PUAE) has resulted in optimum extraction of compounds comparable to hot extraction. Both NIR and ESI-MS provided extended specificity in determination. Conclusion The 5/1-PUAE was determined to be effective, reproducible, simple and energy efficient for the determination of Tx, TxAc and St in P. lanceolata. The offline coupling of NIR and ESI-MS with HPTLC led to considerable improvement in specificity. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 7 July 2014 | 6:28 am

Aroma Evaluation of Setonojigiku (Chrysanthemum japonense var. debile) by Hydrodistillation and Solvent-assisted Flavour Evaporation

Introduction The Chrysanthemum genus consisting of about 200 species is mainly distributed over the Northern Hemisphere. Despite the pleasant odour of C. japonense var. debile (setonojigiku), no detailed analysis of the aroma-active compounds has been reported using sensory evaluation. Objectives Using a hydrodistillation (HD) and a solvent-assisted flavour evaporation (SAFE) method to obtain the volatile oil from the leaf parts. Methods To clarify odorants contributing to the characteristic aroma-active compounds, the aroma-extract dilution analysis (AEDA) method was performed through gas chromatography olfactometry (GC/O) analysis. In addition, the odour activity value (OAV) was calculated in order to determine the relative contribution of each compound to the aroma-active compounds. Results A total of 42 components by HD oil were identified by GC–MS, whereas 34 components were identified in SAFE oil. Thirteen compounds were identified by GC/O analysis in HD and SAFE oils respectively. Conclusion Each extraction method has its own advantages and disadvantages, and they are generally complementary to each other. On the basis of AEDA, OAV and sensory evaluations, [2.2.1] bicyclic monoterpenes (borneol, bornyl acetate and camphor) and ?-caryophyllene are considered to be the main aroma-active compounds of both extraction methods. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 30 June 2014 | 5:59 pm

A Universal Quantitative 1H Nuclear Magnetic Resonance (qNMR) Method for Assessing the Purity of Dammarane-type Ginsenosides

IntroductionQuantitative 1H-NMR (qNMR) is a well-established method for quantitative analysis and purity tests. Applications have been reported in many areas, such as natural products, foods and beverages, metabolites, pharmaceuticals and agriculture. The characteristics of quantitative estimation without relying on special target reference substances make qNMR especially suitable for purity tests of chemical compounds and natural products. Ginsenosides are a special group of natural products drawing broad attention, and are considered to be the main bioactive principles behind the claims of ginsengs efficacy. The purity of ginsenosides is usually determined by conventional chromatographic methods, although these may not be ideal due to the response of detectors to discriminate between analytes and impurities and the long run times involved. ObjectiveTo establish a qNMR method for purity tests of six dammarane-type ginsenoside standards. MethodsSeveral experimental parameters were optimised for the quantification, including relaxation delay (D1), the transmitter frequency offset (O1P) and power level for pre-saturation (PL9). The method was validated and the purity of the six ginsenoside standards was tested. Also, the results of the qNMR method were further validated by comparison with those of high performance liquid chromatography. ConclusionThe qNMR method was rapid, specific and accurate, thus providing a practical and reliable protocol for the purity analysis of ginsenoside standards. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 9 June 2014 | 8:07 pm

A Rapid Extraction and Analysis Method for the Simultaneous Determination of 26 Bioflavonoids in Portulaca Oleracea L.

Introduction Portulaca oleracea L. (P. oleracea, purslane) is an edible plant that is widely distributed around the world, and flavonoids are its main bioactive constituents. Therefore, the detection of flavonoids is very important for a better understanding of its pharmacological actions and to monitor the product quality control of P. oleracea. Objective To develop a rapid method to extract and determine 26 bioflavonoids in P. oleracea, based on microwave extraction (MWE) and triple quadrupole-linear ion trap mass spectrometry. Methods The optimal conditions of MWE for the extraction of flavonoids from P. oleracea involved the use of methanol as the extraction solvent, a microwave power of 300 W, an extraction time of 450 s, and a solvent-to-solid ratio of 30 mL/g. The samples were analysed using an ultra-performance liquid chromatograph coupled with a triple quadrupole-linear ion trap mass spectrometer (UPLC–MS/MS) system. Results The calibration curves of all 26 analytes showed good linearity (r ? 0.999) and the intra- and interday precisions and repeatability were all within required limits. The mean recoveries measured at three concentrations were higher than 94.2%, with RSDs lower than 2.94% for the targets. Conclusion The established MWE/UPLC–MS/MS method is a rapid and effective method for quality evaluation of P. oleracea from different production regions and different harvest periods. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 29 May 2014 | 4:55 pm

Phenolic Compounds Involved in Grafting Incompatibility of Vitis spp: Development and Validation of an Analytical Method for their Quantification

Introduction Graft incompatibility of Vitis spp is an unresolved worldwide problem with important economic consequences. Grafting comprises a complex set of morphological and physiological alterations, in which the phenolic compounds seem to be strongly involved. Therefore, a detailed analysis and recognition of structural phenolic compounds diversity in the two partners of a Vitis graft is of great importance to evaluate their role as markers of graft establishment. Objective To optimise a sample extraction method, and to develop and validate a high-performance liquid chromatography (HPLC) method for the simultaneous determination of phenolic acids and flavonols in the graft union so as to understand their behaviour in the metabolism of the scion–rootstock system, using compatible and incompatible combinations of a Syrah cultivar and two rootstocks (R110 and SO4). Methods Sixty extracts of Vitis grafting tissues were prepared and analysed by HPLC for the qualitative and quantitative determination of their phenolic profile. Results Among the phenolic compounds identified in the samples, one benzoic acid (gallic acid), three cinnamic acids (caffeic acid, ferulic acid and sinapic acid) and two flavonols (catechin and epicatechin) are potentially suitable as markers of graft incompatibility. Conclusion The method developed presents good performance and lends itself readily for application in routine analysis of the phenolic composition of Vitis grafting tissues to distinguish compatible and incompatible combinations in the graft callusing stage. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 29 May 2014 | 4:55 pm

Evaluation of Salacia Species as Anti-diabetic Natural Resources Based on Quantitative Analysis of Eight Sulphonium Constituents: A New Class of ?-Glucosidase Inhibitors

Introduction Stems and roots of Salacia genus plants have been used in Ayurveda as a specific remedy for early stage diabetes. Previous investigations identified four sulphonium sulphates, that is, salacinol (1), kotalanol (3), ponkoranol (5) and salaprinol (7), as the compounds responsible for the anti-diabetic activity. Their desulphonates (2, 4, 6 and 8) were also isolated as active constituents. Two separate quantitative analytical protocols, that is, for 1 and 3 and for 2 and 4, have been developed recently. Objective To: validate the two analytical protocols with respect to all eight sulphoniums; evaluate the quality of a variety of Salacia samples collected in different geographical regions, that is, Thailand, Sri Lanka and India; and determine their distribution in each part of the plant, that is, stems/roots, leaves and fruits. Methods Analyses of four sulphonium sulphates in 32 Salacia extracts were carried out on an Asahipak NH2P-50 column, and those of the corresponding desulphonates were conducted on an Inertsil ODS-3 column. Results Neokotalanol (4) was the major constituent in Salacia samples from Thailand, whereas 1 was the primary constituent in extracts of the stems/roots of plants from Sri Lanka and India. These sulphoniums were only present in trace amounts in leaves and fruits of the plants. Conclusion Two analytical protocols were successfully applied to analyse 32 Salacia samples, and revealed that sulphoniums (1–8) had characteristic distributions due to the plant part and/or due to geographical region. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 9 May 2014 | 5:08 pm

Rapid Chemical Characterisation of Stilbenes in the Root Bark of Norway Spruce by Off-line HPLC/DAD–NMR

Introduction Stilbenes are plant secondary metabolites that have shown promising and varied biological activities. Stilbenes are presently actively studied for the exploitation of this primary raw material resource, involving the concept of biorefining. Methods for the rapid discovery of new and known stilbene structures from various plant sources are thus keenly sought. Objective To establish a simple and rapid technique of off-line HPLC with a diode-array detector (DAD) and NMR for the unambiguous structural elucidation of stilbene structures in the root bark of Norway spruce [Picea abies (L.) Karst.]. Material and methods The stilbene containing fraction was extracted from the plant bark with an ethanol:water mixture (95:5, v/v) preceded by defatting of hydrophobic compounds with n-hexane using the accelerated solvent extraction technique. A portion of the ethanol–water soluble extract was hydrolysed with ?-glucosidase to prepare stilbene aglycones. The extracts were further purified and enriched using a polymeric adsorbent. Stilbene-enriched extracts were directly characterised by off-line HPLC/DAD–NMR in conjunction with HPLC/DAD and HPLC/DAD with electrospray ionisation MSn. Results Trans-isorhapontin and trans-astringin were identified as the major, and trans-piceid as a minor, stilbene glucosides of the bark of roots of Picea abies. Not only stilbene glucosides but also the corresponding stilbene aglycones, such as trans-resveratrol, trans-piceatannol and trans-isorhapontigenin, were rapidly identified from the hydrolysed extract. The acquired heteronuclear single-quantum coherence and heteronuclear multiple bond correlation spectra were used to assign the complete carbon NMR chemical shifts of trans-isorhapontin and trans-astringin without the need of acquiring a 13C-NMR spectrum. Conclusion The off-line HPLC/DAD–NMR method is expedient for the unambiguous identication of structurally similar stilbenes in plant extracts. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 28 April 2014 | 2:48 pm

A Comparative Tissue-specific Metabolite Analysis and Determination of Protodioscin Content in Asparagus Species used in Traditional Chinese Medicine and Ayurveda by use of Laser Microdissection, UHPLC–QTOF/MS and LC–MS/MS

Introduction Asparagus is esteemed in Traditional Chinese Medicine and Ayurveda, and it is commercially one of the most important drugs in the global herbal market. Comparative metabolite profiling of different species would help in determining the similarities and ascertain their validity for being used as substitutes for each other. Laser microdissection (LMD) facilitates identification of metabolites in specific tissues, and thus it can aid in exploration of metabolic pathways in target tissues. Objective To compare tissue-specific metabolites and protodioscin content of Asparagus cochinchinensis (Lour.) Merr. and Asparagus racemosus Willd. used in China and India. Methods Metabolite analysis of laser-dissected tissues was carried out using UHPLC–QTOF/MS and LC–MS/MS. The protodioscin contents were determined and the method was validated as per the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use guidelines. Results Metabolite analysis reveals that the velamen tissue, among other tissues such as cortex, vascular bundles and pith, contained maximum components, specifically those belonging to the steroidal saponin class. Although the metabolite profiles were similar, the content of protodioscin was found to be higher in Chinese than Indian species. Conclusion The study provided a suitable methodology for metabolite profiling and protodioscin content determination of Asparagus by use of LMD, UHPLC–QTOF/MS and LC–MS/MS. The similarities in metabolite profiles indicate that Asparagus species from India and China can serve as substitute for each other in various therapeutic and pharmaceutical applications. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 16 April 2014 | 7:32 am

Identification and Quantitation of Phenolic Compounds from the Seed and Pomace of Perilla frutescens Using HPLC/PDA and HPLC–ESI/QTOF/MS/MS

Introduction Perilla frutescens (L.) Britt., an essential traditional Asian crop and Chinese medicine, potentially exerts anti-oxidation effects through its phenolic compounds. These compounds have already been reported in perilla seed, however, little is reported in Perilla pomace, the primary waste during oil production of Perilla seed. Objective To investigate major phenolic compounds in perilla seeds and pomaces in order to check whether the pomace could be an alternative resource to the seed for nutritional and medical purposes. Methods Compounds in extracts of perilla seeds and pomaces were separated by high-performance liquid chromatography and detected by photodiode array, and by electrospray ionisation with quadrupole time-of-flight tandem mass spectrometry. Herb-markers selected by principal components analysis were then quantified in both seeds and pomaces. Moreover, a fingerprinting approach and multiple discriminant analysis were applied to screen the phenolic markers in 22 samples. Results Ten phenols were tentatively identified, among which four (rosmarinic acid, luteolin, apigenin and rosmarinic acid-3-O-glucoside) were selected as herb-markers. Perilla seeds and pomaces showed similar phenol profiles, however, the pomaces contained almost two times the amount of the four herb-markers than the seeds. Conclusion The results indicated perilla pomace is a promising alternative source of phenolic compounds that could be recovered and potentially used as natural anti-oxidants. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 16 April 2014 | 7:32 am

NoSQL Data Model for Semi-automatic Integration of Ethnomedicinal Plant Data from Multiple Sources

Introduction Sharing traditional knowledge with the scientific community could refine scientific approaches to phytochemical investigation and conservation of ethnomedicinal plants. As such, integration of traditional knowledge with scientific data using a single platform for sharing is greatly needed. However, ethnomedicinal data are available in heterogeneous formats, which depend on cultural aspects, survey methodology and focus of the study. Phytochemical and bioassay data are also available from many open sources in various standards and customised formats. Objective To design a flexible data model that could integrate both primary and curated ethnomedicinal plant data from multiple sources. Materials and methods The current model is based on MongoDB, one of the Not only Structured Query Language (NoSQL) databases. Although it does not contain schema, modifications were made so that the model could incorporate both standard and customised ethnomedicinal plant data format from different sources. Results The model presented can integrate both primary and secondary data related to ethnomedicinal plants. Accommodation of disparate data was accomplished by a feature of this database that supported a different set of fields for each document. It also allowed storage of similar data having different properties. Conclusion The model presented is scalable to a highly complex level with continuing maturation of the database, and is applicable for storing, retrieving and sharing ethnomedicinal plant data. It can also serve as a flexible alternative to a relational and normalised database. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 16 April 2014 | 7:32 am

Ultra-performance LC Separation and Quadrupole Time-of-flight MS Identification of Major Alkaloids in Plumula Nelumbinis

Introduction As an essential medicine and tea source in many countries, Plumula Nelumbinis potentially exerts its major biological activities through its alkaloids. However, the activities of Plumula Nelumbinis are not fully understood due to the lack of studies on its chemical components. Objective To establish an ultra-performance liquid chromatography combined with diode-array detector (UPLC/DAD) method, coupled to an electrospray ionisation with quadrupole time-of-flight mass spectrometry (ESI/QTOF/MS) method, for the separation and identification of Plumula Nelumbinis alkaloids. Methods The eluant from an UPLC separation of an ethanol extract of Plumula Nelumbinis was directly infused into an ESI/QTOF/MS system. Both positive and negative ion modes of ESI with low and high collision energy (CE) were used to obtain sufficient MS information. Results Twenty-one alkaloids were tentatively identified based on their chromatographic characteristics, UV spectra, exact mass, MS fragments and literature reports. They consist of six bis-1-benzyltetrahydroisoquinoline, eleven benzyltetrahydroisoquinoline (including two glycoalkaloids and two quaternary ammoniums), two aporphine, one proaporphine and one indole alkaloids. Eleven were identified in Plumula Nelumbinis for the first time and seven were first reported in Nelumbo nucifera Gaertn. Five compounds, namely norcoclaurine-4?-O-glucoside, norcoclaurine-6-O-glucoside, isolotusine, 6-demethyl-4-demethylN-methylcoclaurine and N-norisoliensinine, were characterised and proposed as new compounds. Conclusion The established UPLC/DAD???ESI/QTOF/MS method is efficient for systematic identification of the alkaloids in Plumula Nelumbinis extract. Copyright © 2014 John Wiley & Sons, Ltd.

Posted on 15 April 2014 | 1:26 am

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