Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Biological potential of extracts of the wild edible Basidiomycete mushroom Grifola frondosa
    Klaus, A. ; Kozarski, M. ; Vunduk, N. ; Todorovic, N. ; Jakovlejevic, D. ; Zizak, Z. ; Pavlovic, V. ; Levic, S. ; Niksic, M. ; Griensven, L.J.L.D. van - \ 2015
    Food Research International 67 (2015). - ISSN 0963-9969 - p. 272 - 283.
    rapid colorimetric assay - antimicrobial properties - chemical-characterization - plant-extracts - immunomodulating activities - antioxidative activities - polysaccharide extracts - antibacterial activity - ganoderma-lucidum - agaricus-bisporus
    Partially purified polysaccharides (FP) and hot alkali extract (FNa) obtained from fruiting bodies of the wild basidiomycete Grifola frondosa were examined for their antimicrobial, antioxidant and cytotoxic activity. The structural properties of FP and FNa samples were investigated by FT-IR and high resolution 1H- and 13C-NMR spectroscopy. From a group of various G - and G + bacteria the antibacterial effects were highest against the G + B. cereus. FNa was the better antioxidant shown by the lower EC50 values of DPPH scavenging ability, ferric-reducing antioxidant power and ferrous ion-chelating ability. Ferric-reducing antioxidant power and ferrous ion-chelating ability were mostly linked to total polysaccharides, total- and ß-glucan content, as well as total protein content. Both extracts displayed a moderate dose dependent antiproliferative action towards malignant human breast cancer MDA-MB-453, cervical adenocarcinoma HeLa and myelogenous leukemia K562 cells not observed in the non cancer derived MRC-5 fibroblasts. The highest effect was found in HeLa cells for FP extract. The mean diameter of Ca-alginate bead loading FP was 960.7 µm while the mean diameter of beads encapsulating FNa extract was 1051.7 µm
    Isolation, identification and activity of natural antioxidants from horehound (Marrubium vulgare L.) cultivated in Lithuania
    Pukalskas, A. ; Venskutonis, P.R. ; Salido, S. ; Waard, P. de; Beek, T.A. van - \ 2012
    Food Chemistry 130 (2012)3. - ISSN 0308-8146 - p. 695 - 701.
    plant-extracts - liquid-chromatography - glycosides - online - leaves - iran - oils
    In an earlier screening of Lithuanian plants, horehound (Marrubium vulgare) showed good antioxidant activity and as this species is used in herbal teas and cough pastilles it was selected for further investigation. Some fractions of the aerial parts were strong scavengers of the model free radicals DPPH and ABTS'. Activity in the beta-carotene bleaching assay and the rapeseed oil oxidation assay was lower. Several active compounds were observed in the crude methanol-water extract, and in butanol and methyl tert-butyl ether fractions using HPLC with on-line radical scavenging detection. After multi-step fractionation of these fractions five compounds possessing radical scavenging activity were purified and their structures were elucidated by NMR and MS as 5,6-dihydroxy-7,4'-dimethoxyflavone (syn. ladanein), 7-O-beta-glucopyranosyl luteolin, 7-O-beta-glucuronyl luteolin, verbascoside and forsythoside B. Their activities were tested in off-line DPPH and ABTS(+) free radical scavenging assays, and compared with the antioxidants rosmarinic acid and Trolox. (C) 2011 Elsevier Ltd. All rights reserved.
    Antioxidant activity assays on-line with liquid chromatography
    Niederländer, H.A.G. ; Beek, T.A. van; Barsatute, A. ; Koleva, I. - \ 2008
    Journal of Chromatography. A, Including electrophoresis and other separation methods 1210 (2008)2. - ISSN 0021-9673 - p. 121 - 134.
    radical scavenging compounds - coulometric array detection - flow-injection system - dpph screening method - dad-spe-nmr - phenolic-compounds - electrochemical detection - natural-products - plant-extracts - chemiluminescence detection
    Screening for antioxidants requires simple in vitro model systems to investigate antioxidant activity. High resolution screening (HRS), combining a separation technique like HPLC with fast post-column (bio)chemical detection can rapidly pinpoint active compounds in complex mixtures. In this paper both electrochemical and chemistry-based assays are reviewed and discussed. The focus is on the mechanisms involved and differences between the assays, rather than on the matrix or analytes. With 45 applications high resolution antioxidant screening has now become an almost routine tool for the rapid identification of antioxidants in plant extracts, foods and beverages. The methods based on true reactive oxygen species (ROS) provide the most realistic measure of antioxidant activity. Unfortunately these methods are difficult to set up and control and have not been applied since they were reported. The methods based on electrochemical detection are more practical, but have still received only limited attention for practical screening purposes. The methods based on a single relatively stable reagent such as DPPH and ABTS+ have become most popular, because of their simple set-up and ease of control. The methods have been combined with on-line DAD, MS and NMR detection for rapid identification of active constituents.
    Evaluation of antioxidative properties of Geranium macrorrhizum and Potentilla fructiosa extracts in Dutch style fermented sausages
    Miliauskas, G. ; Mulder, E. ; Linssen, J.P.H. ; Houben, J.H. ; Beek, T.A. van; Venskutonis, P.R. - \ 2007
    Meat Science 77 (2007)4. - ISSN 0309-1740 - p. 703 - 708.
    plant-extracts - emulsions - spices - oils
    Antioxidative properties of Geranium macrorrhizum, Potentilla fruticosa and Rosmarinus officinalis (as a reference) extracts were evaluated in Dutch style fermented sausages. Extracts were incorporated into sausages during preparation. The sausages were subsequently fermented, tested and compared to a standard spices mix, traditionally used for the production of such sausages. Formation of the primary oxidation products ¿ peroxides, and secondary ¿ TBARS and hexanal was monitored. The polar extracts from Potentilla showed some antioxidant activity, especially in combination with ascorbate, however the activity was low compared to the standard spices mix. Polar extracts from Geranium showed only negligible antioxidant activity.
    Identification of the major constituents of Hypericum perforatum by LC/SPE/NMR and/or LC/MS.
    Tatsis, E.C. ; Boeren, J.A. ; Exarchou, V. ; Troganis, A.N. ; Vervoort, J.J.M. ; Gerothanassis, I.P. - \ 2007
    Phytochemistry 68 (2007)3. - ISSN 0031-9422 - p. 383 - 393.
    st-johns-wort - performance liquid-chromatography - nuclear-magnetic-resonance - solid-phase extraction - dad-spe-nmr - mass-spectrometry - phenolic composition - array detection - plant-extracts - greek oregano
    The newly established hyphenated instrumentation of LC/DAD/SPE/NMR and LC/UV/(ESI)MS techniques have been applied for separation and structure verification of the major known constituents present in Greek Hypericum perforatum extracts. The chromatographic separation was performed on a C18 column. Acetonitrile-water was used as a mobile phase. For the on-line NMR detection, the analytes eluted from column were trapped one by one onto separate SPE cartridges, and hereafter transported into the NMR flow-cell. LC/DAD/SPE/NMR and LC/UV/MS allowed the characterization of constituents of Greek H. perforatum, mainly naphtodianthrones (hypericin, pseudohypericin, protohypericin, protopseudohypericin), phloroglucinols (hyperforin, adhyperforin), flavonoids (quercetin, quercitrin, isoquercitrin, hyperoside, astilbin, miquelianin, I3,II8-biapigenin) and phenolic acids (chlorogenic acid, 3-O-coumaroylquinic acid). Two phloroglucinols (hyperfirin and adhyperfirin) were detected for the first time, which have been previously reported to be precursors in the biosynthesis of hyperforin and adhyperforin
    Comparison of analytical and semi-preparative columns for high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance
    Miliauskas, G. ; Beek, T.A. van; Waard, P. de; Venskutonis, R.P. ; Sudhölter, E.J.R. - \ 2006
    Journal of Chromatography. A, Including electrophoresis and other separation methods 1112 (2006)1-2. - ISSN 0021-9673 - p. 276 - 284.
    natural-products research - hplc-spe-nmr - plant-extracts - identification - hyphenation - ms - spectroscopy - probe - technology - system
    The application of analytical and semi-preparative columns in reversed-phase liquid chromatography-solid-phase extraction-nuclear magnetic resonance (HPLC-SPE-NMR) was compared. The work was aiming at separating a higher sample amount in a single run and in this way to reduce the necessary NMR measurement time of separated compounds. Several parameters for compound separation and trapping procedures were optimised: flow rate of HPLC and make-up water pumps, choice of stationary phase cartridges and drying time. The separation and loadability of nine model compounds on analytical and semi-preparative columns was determined, as well as the focussing capacity of SH-type SPE cartridges. It was found that a semi-preparative column-or multiple peak trapping on analytical columns-gave better results than a standard 4.6mm analytical column for non-polar compounds (e.g. flavonoid aglycones, sesquiterpene lactones, non-polar terpenes, logP>2), but for polar compounds (logP
    Effect of aqueous extract of Acacia nilotica ssp adansonii on milk production and prolactin release in the rat
    Lompo, Z. ; Heide, D. van der; Beek, E.M. van der; Swarts, J.J.M. ; Mattheij, J.A.M. ; Sawadogo, L. - \ 2004
    Journal of Endocrinology 182 (2004)2. - ISSN 0022-0795 - p. 257 - 266.
    mammary-gland development - growth-hormone secretion - plant-extracts - casein synthesis - lactation - induction - protease
    In view of the traditional belief that Acacia nilotica ssp adansonii (AN) can stimulate milk production in lactating women, experiments were performed to determine the effect of an aqueous extract of AN on milk production in rats. Female rats that received oral doses of aqueous extract of this plant during their first lactation produced about 59% more milk than controls (P
    Antioxidant activity of Potentilla fruticosa
    Miliauskas, G. ; Beek, T.A. van; Venskutonis, P.R. ; Linssen, J.P.H. ; Waard, P. de; Sudhölter, E.J.R. - \ 2004
    Journal of the Science of Food and Agriculture 84 (2004)15. - ISSN 0022-5142 - p. 1997 - 2009.
    radical scavenging activity - plant-extracts - flavonoids - lithuania - pomace - herbs
    The molecular structures of the radical scavenging compounds present in extracts of Potentilla fruticosa blossoms were elucidated and the antioxidant activities of various extracts were determined. The activities of the different fractions were monitored by off-line and on-line RP-HPLC DPPH. and ABTS(.+) scavenging methods. Twelve compounds were isolated and identified, namely ellagic acid, catechin, quercetin-3-beta-glucopyranoside, quercetin-3-beta-galactopyranoside, quercetin-3-beta-rutinoside, quercetin-3-beta-glucuronopyranoside, quercetin-3-alpha-arabinofuranoside, kaempferol-3-beta-rutinoside, kaempferol-3-O-beta-(6"-O-(E)-p-coumaroyl)glucopyranoside, rhamnetin-3-beta-glucopyranoside and rhamnetin-3-beta-galactopyranoside. The radical scavenging activity of each isolated compound was measured using DPPH. and ABTS(.+) assays and compared with the activity of rosmarinic acid. Catechin and ellagic acid were found to be the most active radical scavengers. The antioxidant properties of plant fractions were assessed in model systems by measuring superoxide anion and hydrogen peroxide scavenging, beta-carotene bleaching, hexanal production in edible oil, peroxide formation, and the increase in UV absorbance in the course of oxidation. (C) 2004 Society of Chemical Industry.
    Different arabinogalactan proteins (AGPs) are present in carrot (Daucus carota L.) cell culture medium and in seeds
    Immerzeel, P. ; Schols, H.A. ; Voragen, A.G.J. ; Vries, S.C. de - \ 2004
    Physiologia Plantarum 122 (2004)2. - ISSN 0031-9317 - p. 181 - 189.
    somatic embryogenesis - plant-extracts - polysaccharides - chromatography - sugars - wall
    Arabinogalactan proteins (AGPs) were isolated by Yariv phenylglycoside precipitation from the medium of carrot (Daucus carota L.) cell cultures and from carrot seeds. The isolates showed a different composition of AGPs. The medium AGPs contained an arabinose poor AGP fraction that had relatively high levels of glucuronic acid and rhamnose. In contrast the seed AGPs only contained arabinose and galactose-rich AGP fractions that had low levels of glucuronic acid. Linkage analysis on all fractions showed that most of the arabinose residues were terminally linked and that almost all galactose was present in the 1,3-, 1,6- and 1,3,6- form. The strongly branched type II arabinogalactans are characteristic of the carbohydrate part of AGPs. AGP characteristic amino acid residues as Hyp, Pro, Glx, Ser, Gly, Asx, Ala, Leu and Thr were detected in three different fractions.
    Antioxidative activity of Geranium macrorrhizum
    Miliauskas, G. ; Beek, T.A. van; Venskutonis, P.R. ; Linssen, J.P.H. ; Waard, P. de - \ 2004
    European Food Research and Technology 218 (2004)3. - ISSN 1438-2377 - p. 253 - 261.
    radical scavenging activity - plant-extracts - rapeseed oil - flavonoids - l. - identification - lithuania - tannins - leaves - pomace
    The composition of radical-scavenging compounds from Geranium macrorrhizum leaves was analyzed and the antioxidative activities of various extracts was determined. Seven compounds, namely gallic acid, ellagic acid, 4-galloyl quinic acid, the flavonoid quercetin and three of its glycosides, quercetin-3-beta-glucopyranoside, quercetin-3-beta-galactopyranoside and quercetin-4'-beta-glucopyranoside were isolated and identified in the various fractions. The radical-scavenging activity of the isolated compounds was measured using DPPHcircle and ABTS(circle+) scavenging assays and compared with the activity of rosmarinic acid. Quercetin-3-glucopyranoside and quercetin-3-galactopyranoside showed the highest antioxidative capacities. Antioxidative activities of all plant fractions were assessed by model system tests (superoxide anion and hydrogen peroxide scavenging) and by oxidation tests (beta-carotene bleaching, peroxide value, UV absorbance and headspace-gas chromatography hexanal determination). The ethanol-butanol fraction of the plant possessed the highest activity in most of the tests.
    LC-UV-solid-phase extraction-NMR-MS combined with a cryogenic flow probe and its application to the identification of compounds present in Greek oregano
    Exarchou, V. ; Godejohann, M. ; Beek, T.A. van; Gerothanassis, I.P. ; Vervoort, J.J.M. - \ 2003
    Analytical Chemistry 75 (2003)22. - ISSN 0003-2700 - p. 6288 - 6294.
    magnetic-resonance-spectroscopy - performance liquid-chromatography - high-resolution nmr - tandem mass-spectrometry - to-noise ratio - hplc-nmr - solvent-suppression - natural-products - plant-extracts - constituents
    Structure elucidation of natural products usually relies on a combination of NMR spectroscopy with mass spectrometry whereby NMR trails MS in terms of the minimum sample amount required. In the present study, the usefulness of on-line solid-phase extraction (SPE) in LC-NMR for peak storage after the LC separation prior to NMR analysis is demonstrated. The SPE unit allows the use of normal protonated solvents for the LC separation and fully deuterated solvents for flushing the trapped compounds to the NAIR probe. Thus, solvent suppression is no longer necessary. Multiple trapping of the same analyte from repeated LC injections was utilized to solve the problem of low concentration and to obtain 2D heteronuclear NMR spectra. In addition, a combination of the SPE unit with a recently developed cryoflow NMR probe and an MS was evaluated. This on-line LC-UV-SPE-NMR-MS system was used for the automated analysis of a Greek oregano extract. Combining the data provided by the UV, MS, and NMR spectra, the flavonoids taxifolin, aromadendrin, eriodictyol, naringenin, and apigenin, the phenolic acid rosmarinic acid, and the monoterpene carvacrol were identified. This automated technique is very useful for natural product analysis, and the large sensitivity improvement leads to significantly reduced NAIR acquisition times.
    Antioxidant activity screening of extracts from Sideritis species (Labiatae) grown in Bulgaria
    Koleva, I. ; Linssen, J.P.H. ; Beek, T.A. van; Evstatieva, L.N. ; Kortenska, V. ; Handjieva, N. - \ 2003
    Journal of the Science of Food and Agriculture 83 (2003)8. - ISSN 0022-5142 - p. 809 - 819.
    radical-scavenging activity - oxidative stability - plant-extracts - oil - flavonoids - glycosides - emulsions
    Plant samples from several species and populations of the genus Sideritis (Labiatae) grown in Bulgaria (S scardica, S syriaca and S montana) were extracted with different solvents. Their antioxidant activities were determined by the -carotene bleaching test (BCBT), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method and static headspace gas chromatography (HS-GC) and compared with the antioxidant activity of two reference compounds of different polarity, viz butylated hydroxytoluene (BHT) and rosmarinic acid. The pure reference compounds were applied in a ten-times lower concentration than the plant extracts. The highest antioxidant activity in the BCBT, close to that of BHT, was observed for the more apolar extracts. The inhibitory effect on -carotene bleaching of the polar extracts and rosmarinic acid was much lower than that of BHT. The inhibition of hexanal formation in bulk safflower oil by most of S syriaca and S scardica extracts was as effective as BHT but less so than rosmarinic acid. S montana extracts showed weak antioxidant or even pro-oxidant properties. Extracts from butanol and from ethyl acetate and the total methanol extracts from all Sideritis plants studied showed a strong radical scavenging activity against DPPH, close to that of rosmarinic acid. S montana extracts were, as a whole, slightly weaker radical inhibitors than the extracts from the other two species. The antioxidant activity of Sideritis extracts was attributed to the presence of flavonoid and phenylpropanoid glycosides
    Identification of Radical Scavengers in Sweet Grass (Hierochloe odorata)
    Pukalskas, A. ; Beek, T.A. van; Venskutonis, R.P. ; Linssen, J.P.H. ; Veldhuizen, A. van; Groot, Æ. de - \ 2002
    Journal of Agricultural and Food Chemistry 50 (2002)10. - ISSN 0021-8561 - p. 2914 - 2919.
    antioxidant activity - plant-extracts - oil
    Extracts from aerial parts of sweet grass (Hierochloe odorata) were active DPPH free radical scavengers, The active compounds were detected in extract fractions using HPLC with on-line radical scavenging detection. After multistep fractionation of the extract, two new natural products possessing radical scavenging activity were isolated, and their structures were elucidated by NMR and MS. They were identified as 5,8-dihydroxybenzopyranone and 5-hydroxy-8-O-beta-D-glucopyranosyl-benzopyranone. Activities of the compounds isolated were tested by DPPH and ABTS free radical scavenging assays, and compared with the known natural antioxidant rosmarinic acid and Trolox.
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