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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    A benchmarking protocol for breath analysis: The peppermint experiment
    Henderson, Ben ; Ruszkiewicz, Dorota M. ; Wilkinson, Max ; Beauchamp, Jonathan D. ; Cristescu, Simona M. ; Fowler, Stephen J. ; Salman, Dahlia ; Francesco, Fabio Di; Koppen, Gudrun ; Langejürgen, Jens ; Holz, Olaf ; Hadjithekli, Andria ; Moreno, Sergi ; Pedrotti, Michele ; Sinues, Pablo ; Slingers, Gitte ; Wilde, Michael ; Lomonaco, Tommaso ; Zanella, Delphine ; Zenobi, Renato ; Focant, Jean François ; Grassin-Delyle, Stanislas ; Franchina, Flavio Antonio ; Malásková, Michaela ; Stefanuto, Pierre Hugues ; Pugliese, Giovanni ; Mayhew, Christopher ; Thomas, C.L.P. - \ 2020
    Journal of Breath Research 14 (2020)4. - ISSN 1752-7155
    benchmark - breathomics - peppermint - repeated sampling8pharmacokinetics - standardization

    Sampling of volatile organic compounds (VOCs) has shown promise for detection of a range of diseases but results have proved hard to replicate due to a lack of standardization. In this work we introduce the 'Peppermint Initiative'. The initiative seeks to disseminate a standardized experiment that allows comparison of breath sampling and data analysis methods. Further, it seeks to share a set of benchmark values for the measurement of VOCs in breath. Pilot data are presented to illustrate the standardized approach to the interpretation of results obtained from the Peppermint experiment. This pilot study was conducted to determine the washout profile of peppermint compounds in breath, identify appropriate sampling time points, and formalise the data analysis. Five and ten participants were recruited to undertake a standardized intervention by ingesting a peppermint oil capsule that engenders a predictable and controlled change in the VOC profile in exhaled breath. After collecting a pre-ingestion breath sample, five further samples are taken at 2, 4, 6, 8, and 10 h after ingestion. Samples were analysed using ion mobility spectrometry coupled to multi-capillary column and thermal desorption gas chromatography mass spectrometry. A regression analysis of the washout data was used to determine sampling times for the final peppermint protocol, and the time for the compound measurement to return to baseline levels was selected as a benchmark value. A measure of the quality of the data generated from a given technique is proposed by comparing data fidelity. This study protocol has been used for all subsequent measurements by the Peppermint Consortium (16 partners from seven countries). So far 1200 breath samples from 200 participants using a range of sampling and analytical techniques have been collected. The data from the consortium will be disseminated in subsequent technical notes focussing on results from individual platforms.

    Molecular cloning and characterization of a broad substrate terpenoid oxidoreductase from Artemisia annua.
    Ryden, A.M. ; Ruyter-Spira, C.P. ; Litjens, R. ; Takahashi, S. ; Quax, W.J. ; Osada, H. ; Bouwmeester, H.J. ; Kayser, O. - \ 2010
    Plant and Cell Physiology 51 (2010)7. - ISSN 0032-0781 - p. 1219 - 1228.
    chain dehydrogenases/reductases sdrs - amorpha-4,11-diene synthase - functional assignments - biosynthetic-pathway - essential oil - key enzyme - expression - reductase - peppermint - acid
    From Artemisia annua L., a new oxidoreductase (Red 1) was cloned, sequenced and functionally characterized. Through bioinformatics, heterologous protein expression, and enzyme substrate conversion assays, the elucidation of the enzymatic capacities of Red1 was achieved. Red1 acts on monoterpenoids, and in particular functions as a menthone:neomenthol oxidoreductase. The kinetic parameter kcat/Km was determined to be 939 fold more efficient for the reduction of (-)-menthone to (+)-neomenthol, than results previously reported for the menthone:neomenthol reductase from Mentha x piperita. Based on its kinetic properties, the possible use of Red1 in biological crop protection is discussed.
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