Bernd Schneider

Thompson Institute, Итак, New York, United States

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Publications (241)643.34 Total impact

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    ABSTRACT: Infrared-guided chromatographic fractionation of sesquiterpene lactones from the extracts of Cousinia aitchisonii and Cousinia concolor led to the isolation of five pure compounds. A new sesquiterpene lactone, namely, aitchisonolide, and two known sesquiterpene lactones (desoxyjanerin and rhaserolide) were isolated from C. aitchisonii and two known lignans (arctiin and arctigenin) from C. concolor. The structures of these compounds were elucidated by one-dimensional and two-dimensional nuclear magnetic resonance techniques, as well as high-resolution mass spectrometry. The purified and characterized compounds were subjected to cytotoxicity assay. The sesquiterpene lactones desoxyjanerin and rhaserolide showed significant cytotoxic activities against five different cancer cell lines and the normal human embryonic kidney cell line. Rhaserolide was chosen to evaluate the possible mechanism of action. Western blot analysis revealed that rhaserolide could induce apoptosis in Jurkat cells via the activation of c-Jun n-terminal kinase phosphorylation. Copyright © 2015 John Wiley & Sons, Ltd.
    Phytotherapy Research 11/2015; DOI:10.1002/ptr.5519 · 2.66 Impact Factor
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    ABSTRACT: The acyclic monoterpene alcohol linalool is one of the most frequently encountered volatile compounds in floral scents. Various linalool oxides are usually emitted along with linalool, some of which are cyclic, such as the furanoid lilac compounds. Recent work has revealed the coexistence of two flower-expressed linalool synthases that produce the (S)- or (R)-linalool enantiomers and the involvement of two P450 enzymes in the linalool oxidation in the flowers of Arabidopsis thaliana. Partially redundant enzymes may also contribute to floral linalool metabolism. Here, we provide evidence that CYP76C1 is a multifunctional enzyme that catalyzes a cascade of oxidation reactions and is the major linalool metabolizing oxygenase in Arabidopsis flowers. Based on the activity of the recombinant enzyme and mutant analyses, we demonstrate its prominent role in the formation of most of the linalool oxides identified in vivo, both as volatiles and soluble conjugated compounds, including 8-hydroxy, 8-oxo, and 8-COOH-linalool, as well as lilac aldehydes and alcohols. Analysis of insect behavior on CYP76C1 mutants and in response to linalool and its oxygenated derivatives demonstrates that CYP76C1-dependent modulation of linalool emission and production of linalool oxides contribute to reduced floral attraction and favor protection against visitors and pests.
    The Plant Cell 10/2015; 27(10). DOI:10.1105/tpc.15.00399 · 9.34 Impact Factor
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    Oliver Kayser · Nizar Happyana · Bernd Schneider ·

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    ABSTRACT: The evolutionary plant-herbivore arms race sometimes gives rise to remarkably unique adaptation strategies. Here we report one such strategy in the lepidopteran herbivore Manduca sexta against its hostplant Nicotiana attenuataa € s major phytotoxins, 17-hydroxygeranyllinalool diterpene glycoside, lyciumoside IV and its malonylated forms. We show that alkalinity of larval regurgitant non-enzymatically demalonylates the malonylated forms to lyciumoside IV. Lyciumoside IV is then detoxified in the midgut by β-glucosidase 1-catalysed deglycosylation, which is unusual, as typically the deglycosylation of glycosylated phytochemicals by insects results in the opposite: toxin activation. Suppression of deglucosylation by silencing larval β-glucosidase 1 by plant-mediated RNAi causes moulting impairments and mortality. In the native habitat of N. attenuata, β-glucosidase 1 silencing also increases larval unpalatability to native predatory spiders, suggesting that the defensive co-option of lyciumoside IV may be ecologically advantageous. We infer that M. sexta detoxifies this allelochemical to avoid its deleterious effects, rather than co-opting it against predators. © 2015 Macmillan Publishers Limited. All rights reserved.
    Nature Communications 10/2015; 6:8525. DOI:10.1038/ncomms9525 · 11.47 Impact Factor
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    ABSTRACT: Apple proliferation (AP) is caused by a psyllid‐transmitted phytoplasma and is one of the most economically important diseases on apple in Europe. AP was first reported in northern Italy and in the following years from many European countries. Previous research on phytoplasma‐ induced diseases of rosaceous fruit trees (mainly AP, pear decline and European stone fruit yellows), exhibits strong evidence that phloem injuries play a central and probably universal role in phytoplasma pathogenicity. The effect of phytoplasma infections on phloem function and the resulting diseases received little attention in the past. Phytoplasma infection severely impairs assimilate translocation in host plants and might be responsible for massive changes in phloem physiology including signalling components. As shown for other phytoplasma species, infection brings about Ca2+ influx into sieve tubes, leading to sieve‐tube occlusion by callose deposition or protein plugging, which is assumed also for AP phytoplasma. Effectors may cause gating of sieve‐element Ca2+ channels leading to sievetube occlusion with presumptive dramatic effects on phytoplasma spread, photoassimilate distribution and the whole phloem physiology. However, there is indication that phloem loading is affected by phytoplasma infection. As sieve elements need a permanent input of energy to ensure their viability, sugar metabolism and the associate energy production of the companion cells have a dramatic impact on the physiological fitness of phloem function. It is presumptive that signalling substances are produced prior sieve‐element occlusion to ensure the spread throughout the plant body. Analyses of diverse phytohormones in response to challenge with AP phytoplasma show a strong increase of salicylic acid accompanied by a decrease of jasmonic acid. This supports the idea that phytohormones have a role in plant defence signalling against phytoplasma infection. It is a matter of debate whether mechanisms involved in phloem impairment could differ between pathosystems and vary with the plant susceptibility to infection.
    Endocytobiosis and Cell Research 10/2015; 26:67-75.
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    William Hidalgo · Marco Kai · Bernd Schneider ·
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    ABSTRACT: In vitro root cultures of Anigozanthos preissii and Wachendorfia thyrsiflora (Haemodoraceae) are suitable biological systems for studying the biosynthesis of phenylphenalenones. Here we report how we used these root cultures to investigate precursor-product relationships between phenylpropanoids and phenylphenalenones whose phenyl rings share identical substitution patterns. Four phenylpropanoic acids, including ferulic acid and the unusual 4-methoxycinnamic acid, were used in (13)C-labeled form as substrates to study their incorporation into phenylphenalenones. In addition to the previously reported 2-hydroxy-9-(4'-hydroxy-3'-methoxyphenyl)-1H-phenalen-1-one (trivial name musanolone F), 2-hydroxy-9-(4'-methoxyphenyl)-1H-phenalen-1-one (proposed trivial name 4'-methoxyanigorufone) was found as a biosynthetic product in A. preissii. The carbon skeleton of 4'-methoxycinnamic acid was biosynthetically incorporated as an intact unit including its 4'-O-methyl substituent at the lateral phenyl ring. 4'-Methoxyanigorufone is reported here for the first time as a natural product. Copyright © 2015. Published by Elsevier Ltd.
    Phytochemistry 09/2015; 13. DOI:10.1016/j.phytochem.2015.07.017 · 2.55 Impact Factor
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    ABSTRACT: Phenylphenalenones, polycyclic aromatic natural products from some monocotyledonous plants, are known as phytoalexins in banana (Musa spp.). In this study, (1) H NMR-based metabolomics along with liquid chromatography and mass spectrometry were used to explore the chemical responses of the susceptible 'Williams' and the resistant 'Khai Thong Ruang' Musa varieties to the ascomycete fungus Mycosphaerella fijiensis, the agent of the Black Leaf Sigatoka Disease. Principal component analysis discriminated strongly between infected and non-infected plant tissue, mainly due to specialized metabolism induced in response to the fungus. Phenylphenalenones are among the major induced compounds, and the resistance level of the plants was correlated with the progress of the disease. However, a virulent strain of M. fijiensis was able to overcome plant resistance by converting phenylphenalenones to sulfate conjugates. Here we report the first metabolic detoxification of fungitoxic phenylphenalenones to evade the chemical defense of Musa plants. This article is protected by copyright. All rights reserved.
    Plant Cell and Environment 08/2015; DOI:10.1111/pce.12630 · 6.96 Impact Factor
  • Alexander V Baranovsky · Dmitry A Bolibrukh · Bernd Schneider ·
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    ABSTRACT: The ethanol solvolysis of 3-methoxy-14,17-etheno-16α-nitroestra-1,3,5(10)-trien-17β-yl acetate in the presence of NaHCO3 was studied by means of real-time NMR experiments, LC-SPE-NMR, and LC-MS. The pathway to form 3-methoxy-2'-oxopyrrolidino-[4',5':14β,15β]-estra-1,3,5(10)-trien-17-one was disclosed. The intermediacy of nitrile oxide and alkoxynitrone was postulated based on the analysis of the reaction products. The proposed mechanism of cleaving the bridge in the nitro compound is legal for the formation of N-acetoxylactams, nitriles, isoxazoles and isoxazolines. Copyright © 2015. Published by Elsevier Inc.
    Steroids 08/2015; DOI:10.1016/j.steroids.2015.08.009 · 2.64 Impact Factor
  • Katharina Zenger · Sara Agnolet · Bernd Schneider · Birgit Kraus ·
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    ABSTRACT: The in vitro metabolism of flavokawain A, B and C (FKA, FKB, FKC), methoxylated chalcones from Piper methysticum, was examined using human liver microsomes. Phase I and phase II (glucuronidation) metabolism as well as combined phase I+II metabolism were studied. For identification and structure elucidation of microsomal metabolites, LC-HRESIMS and NMR techniques were applied. Major phase I metabolites were generated by demethylation in position C-4 or C-4' and hydroxylation predominantly in position C-4, yielding FKC as phase I metabolite of FKA and FKB, helichrysetin as metabolite of FKA and FKC, and cardamonin as metabolite of FKC. To an even greater extent, flavokawains were metabolized in presence of uridine diphosphate (UDP) glucuronic acid by microsomal UDP-glucuronosyl transferases. For all flavokawains, monoglucuronides (FKA-2'-O-glucuronide, FKB-2'-O-glucuronide, FKC-2'-O-glucuronide, FKC-4-O-glucuronide) were found as major phase II metabolites. The dominance of generated glucuronides suggests a role of conjugated chalcones as potential active compounds in vivo.
    Journal of Agricultural and Food Chemistry 06/2015; 63(28). DOI:10.1021/acs.jafc.5b01858 · 2.91 Impact Factor
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    ABSTRACT: Evaluation of 4-phenylphenalenones and structural analogues against the fungal pathogen Mycosphaerella fijiensis (causal agent of black sigatoka disease in bananas) under light-controlled conditions uncovered some key structural features for the design of photodynamic compounds. SAR analysis revealed the importance of a chromophoric aryl-ketone and a "steroidomimetic" structural motif in the activity of the assayed compounds. The results pointed to the evaluation of 1,2-dihydro-3H-naphtho[2',1':3,4]cyclohepta[1,2-b]furan-3-one which displayed an activity in the range of propiconazole but with photodynamic behavior. The present work demonstrates that 1,2-dihydro-3H-naphtho[2',1':3,4]cyclohepta[1,2-b]heterocyclic-3-one derivatives can be used as potential lead compounds for the development of fungicides which relies on a dual mode of action. This article is protected by copyright. All rights reserved.
    Pest Management Science 06/2015; DOI:10.1002/ps.4055 · 2.69 Impact Factor
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    ABSTRACT: Arabidopsis PENETRATION (PEN) genes quantitatively contribute to the execution of different forms of plant immunity upon challenge with diverse leaf pathogens. PEN3 encodes a plasma membrane-resident pleiotropic drug resistance-type ATP-binding cassette transporter and is thought to act in a pathogen-inducible and PEN2 myrosinase-dependent metabolic pathway in extracellular defense. This metabolic pathway directs the intracellular biosynthesis and activation of tryptophan (Trp)-derived indole glucosinolates for subsequent PEN3-mediated efflux across the plasma membrane at pathogen contact sites. However, PEN3 functions also in abiotic stress responses to cadmium and indole-3-butyric acid (IBA)-mediated auxin homeostasis in roots, raising the possibility that PEN3 exports multiple functionally unrelated substrates. Here we describe the isolation of a pen3 allele, designated pen3-5, which encodes a dysfunctional protein that accumulates in planta like wild-type PEN3. The specific mutation in pen3-5 uncouples PEN3 functions in IBA-stimulated root growth modulation, flg22-induced callose deposition and pathogen-inducible salicylic acid accumulation from PEN3 activity in extracellular defense, indicating the engagement of multiple PEN3 substrates in different PEN3-dependent biological processes. We identified 4-O-β-D-glucosyl-indol-3-yl formamide (4OGlcI3F) as a pathogen-inducible Trp-derived compound that over-accumulates in pen3 leaf tissue and whose biosynthesis is dependent on an intact PEN2 metabolic pathway. We propose that a precursor(s) of 4OGlcI3F is the PEN3 substrate in extracellular pathogen defense. These precursors, the shared indole core present in IBA and 4OGlcI3F, and allele-specific uncoupling of a subset of PEN3 functions, suggest that PEN3 transports distinct indole-type metabolites in distinct biological processes. Copyright © 2015, Plant Physiology.
    Plant physiology 05/2015; 168(3):814-827. DOI:10.1104/pp.15.00182 · 6.84 Impact Factor
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    ABSTRACT: The banana epidermis and in particular their stomata are conducive sites for the penetration of pathogenic fungi which can severely limit global banana production. The red pseudostem of the ornamental banana Musa acuminata ssp. zebrina cv. 'Rowe Red' was used to study the chemical constituents of the epidermal cell layer using matrix-free laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometric imaging (LDI-FT-ICR-MSI). The high resolution of this technique allowed phenylphenalenone-type compounds to be located in single plant cells. Some of these secondary metabolites were identified as constitutive compounds and found in specialized epidermal cells in banana pseudostem tissue. Especially the red paracytic stomata revealed higher signal intensities of certain phenylphenalenones than normal epidermis cells. The ease of detection of polycyclic aromatic compounds on the cellular level is discussed with regard to future investigations of plant-pathogen interactions. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Phytochemistry 05/2015; 116(1). DOI:10.1016/j.phytochem.2015.04.010 · 2.55 Impact Factor
  • Felix Feistel · Christian Paetz · Sybille Lorenz · Bernd Schneider ·
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    ABSTRACT: The absolute configuration of salicortin, HCH-salicortin and tremulacin, isolated from leaves of Populus trichocarpa × deltoides Beaupré, was determined by comparing spectroscopic data of these compounds with those of idescarpin, isolated from leaves of Idesia polycarpa. All compounds were characterized by nuclear magnetic resonance spectroscopy, high-resolution mass spectrometry, and circular dichroism spectroscopy. It was found that the hydroxy cyclohexenonoyl (HCH) moiety in all compounds is (S)-configured. In addition, it was shown that leaves of Idesia polycarpa contain high amounts of (-)-idescarpin (1.1%, based on dry weight).
    Molecules 04/2015; 20(4):5566-73. DOI:10.3390/molecules20045566 · 2.42 Impact Factor
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    ABSTRACT: The secondary metabolites in the roots, leaves and flowers of the common dandelion (Taraxacum officinale agg.) have been studied in detail. However, little is known about the specific constituents of the plant's highly specialized laticifer cells. Using a combination of liquid and gas chromatography, mass spectrometry and nuclear magnetic resonance spectrometry, we identified and quantified the major secondary metabolites in the latex of different organs across different growth stages in three genotypes, and tested the activity of the metabolites against the generalist root herbivore Diabrotica balteata. We found that common dandelion latex is dominated by three classes of secondary metabolites: phenolic inositol esters (PIEs), triterpene acetates (TritAc) and the sesquiterpene lactone taraxinic acid β-d-glucopyranosyl ester (TA-G). Purification and absolute quantification revealed concentrations in the upper mgg(-1) range for all compound classes with up to 6% PIEs, 5% TritAc and 7% TA-G per gram latex fresh weight. Contrary to typical secondary metabolite patterns, concentrations of all three classes increased with plant age. The highest concentrations were measured in the main root. PIE profiles differed both quantitatively and qualitatively between plant genotypes, whereas TritAc and TA-G differed only quantitatively. Metabolite concentrations were positively correlated within and between the different compound classes, indicating tight biosynthetic co-regulation. Latex metabolite extracts strongly repelled D. balteata larvae, suggesting that the latex constituents are biologically active. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Phytochemistry 02/2015; 115(1). DOI:10.1016/j.phytochem.2015.01.003 · 2.55 Impact Factor
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    ABSTRACT: Plant pathogenic phytoplasmas found in wild grasses in East Africa could pose a serious threat to the cultivation of Napier grass, Pennisetum purpureum, the most important livestock fodder in the region. To asses this threat, leaves from plants of 33 grass species were sampled from Mbita, Bungoma and Busia districts in western Kenya, Tarime district in northern Tanzania and Busia and Bugiri districts in the eastern Uganda to determine which species host phytoplasmas, their identity and their relationship with disease symptoms. Phytoplasmas were detected using universal primers based on conserved phytoplasma-specific 16S rDNA sequence motives infrom 11 grass species collected. Sequence and phylogenetic analysis revealed the presence of Napier grass stunt (NGS)- related phytoplasmas in 11 grass species, ‘Candidatus Phytoplasma cynodontis’ in three, and goosegrass white leaf (GGWL) phytoplasma in two wild grass species. This study showed that the geographical distribution, diversity of phytoplasmas and their grass host species in East Africa is greater than antecedently thought and that typical disease symptoms including white leaf or stunting alone are not always reliable indicators of the presence of phytoplasma. It also shows the need to identify insect vectors responsible for phytoplasma transmission from native grasses to Napier grass or other cereals present in the region.
    Plant Disease 02/2015; DOI:10.1094/PDIS-11-14-1173-RE · 3.02 Impact Factor
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    ABSTRACT: Flaxseed is an important source of lignans and ω-3 fatty acids, compounds which present interest in human health with many applications in food industry. It is therefore necessary to precisely know the metabolite content in flaxseed. A metabolomic approach using NMR was developed to achieve this goal. Due to particular characteristics of flaxseed (high level in oil, high amount in mucilage, and integration of the phenolics into a macromolecule), the extraction procedure had first to be optimized using an experimental design, based on the extraction time, in a water bath or an ultrasound bath, alkaline treatment, defatting, and centrifugation temperature. This methodology was then applied to several flaxseed varieties classified in function of their content in ω-3 fatty acid. The main differences in semi-polar metabolites between these varieties concern compounds of the phenylpropanoid pathway. Hydroxycinnamic acid glucoside and lignan content increase when ω-3 fatty acid content decrease whereas flavonoid content increase in the same way of ω-3 fatty acids.
    Metabolomics 12/2014; 10(6). DOI:10.1007/s11306-014-0664-8 · 3.86 Impact Factor
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    ABSTRACT: Abutilon theophrasti Medik., previously found to be rather insensitive to benzoxazinoid containing rye mulch and the allelochemical benzoxazolin-2(3H)-one (BOA), can be associated with the zygomycete Actinomucor elegans, whereby the fungus colonizes the root relatively superficially and mainly in the maturation zone. The fungus mitigates necrosis of the cotyledons when seedlings are incubated with 2 mM BOA, in contrast to those that lack the fungus. In liquid cultures of the fungus, tryptophan was identified. The accumulation of tryptophan is increased in presence of BOA. This amino acid seems to be important in protecting Abutilon against BOA and its derivatives since it suppressed the accumulation of BOA derived, highly toxic 2-aminophen-oxazin-3-one (APO) in the medium and on the root surface during BOA incubations of Abutilon seedlings. Although A. elegans is insensitive to BOA and APO, the fungus is not able to protect the plant against harmful effects of APO, when seedlings are treated with the compound. Abutilon can detoxify BOA via BOA-6-OH glucosylation probably by a cell wall associated glucosyltransferase, but only low amounts of the product accumulate. Low tryptophan concentrations can contribute to a degradation of the toxic intermediate BOA-6-OH by Fenton reactions, whereby the amino acid is oxidized. One of the oxidation products was identified as 4(1H)-quinolinone, which is the core substructure of the quorum sensing molecule 2-heptyl-3-hydroxy-4-quinolone. The mutualistic association of Abutilon theophrasti with Actinomucor elegans is considered as opportunistic and facultative. Such plant-fungus associations depend rather likely on environmental conditions, such as the mode of fertilization.
    Journal of Chemical Ecology 11/2014; DOI:10.1007/s10886-014-0529-7 · 2.75 Impact Factor
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    ABSTRACT: Abstract Context: Ferula foetida Regel (Apiaceae) is an Iranian medicinal plant with various biological activities including antispasmodic and anthelmintic. Objective: The sulfur compounds from the roots of F. foetida were isolated and characterized to test their cytotoxic and antimicrobial activities. Materials and methods: The methanolic extract of the roots of F. foetida was fractionated using silica column chromatography. The components of each fraction were further purified using RP-HPLC. Their structures were elucidated by 1- and 2-D NMR spectroscopy as well as HREIMS. Their cytotoxic and antimicrobial activities were evaluated using Alamar Blue assay and broth microdilution method, respectively. Results: Four new thiophene derivatives, namely foetithiophenes C-F (3-6), together with four known compounds, foetithiophenes A (1) and B (2), coniferaldehyde, and sinapic aldehyde, were isolated from the roots of F. foetida. Antimicrobial activities were observed in particular against the Gram-positive bacteria. The best antimicrobial activity was observed for compound 6 against B. cereus with a MIC value 50 µg/mL. The tested compounds did not show cytotoxic properties against MCF-7 and K562 cells. Conclusion: Four new thiophene derivatives including foetithiophenes C-F (3-6) were characterized from the roots of F. foetida. Foetithiophene F (6) exhibited the most potent activity against the Gram-positive bacteria B. cereus.
    Pharmaceutical Biology 11/2014; 53(5):1-5. DOI:10.3109/13880209.2014.939765 · 1.24 Impact Factor

Publication Stats

4k Citations
643.34 Total Impact Points


  • 2015
    • Thompson Institute
      Итак, New York, United States
  • 1998-2015
    • Max Planck Institute for Chemical Ecology
      • • Department of Biochemistry
      • • Department of Molecular Ecology
      • • Department of Bioorganic Chemistry
      Jena, Thuringia, Germany
    • Leibniz Institute for Plant Biochemistry
      Halle-on-the-Saale, Saxony-Anhalt, Germany
  • 2014
    • Universität Ulm
      • Institute of Natural Medicine and Clinical Pharmacology
      Ulm, Baden-Württemberg, Germany
  • 2008-2014
    • Julius Kühn-Institut
      • Institute for Plant Protection in Fruit Crops and Viticulture
      Stadt Quedlinburg, Saxony-Anhalt, Germany
  • 2007-2014
    • Max Planck Institute for Biogeochemistry Jena
      Jena, Thuringia, Germany
    • Federal Agency for Agriculture and Food (Germany)
      Berlín, Berlin, Germany
  • 2010
    • Kunming University of Science and Technology
      Yün-nan, Yunnan, China
  • 2008-2010
    • Mashhad University of Medical Sciences
      • Department of Pharmacognosy
      Mashad, Razavi Khorasan, Iran
  • 2005
    • Max Planck Institute for Plant Breeding Research
      • Department of Plant Microbe Interactions
      Köln, North Rhine-Westphalia, Germany
  • 2002
    • Martin Luther University Halle-Wittenberg
      • Institute of Chemistry
      Halle-on-the-Saale, Saxony-Anhalt, Germany
    • National Academy of Sciences of Belarus
      • Institute of Bioorganic Chemistry
      Myenyesk, Minsk, Belarus