Search Results - "Pras, Niesko"

Seasonal variation of artemisinin and its biosynthetic precursors in plants of Artemisia annua of different geographical origin: proof for the existence of chemotypes by Wallaart, T E, Pras, N, Beekman, A C, Quax, W J

“…The time course of the levels of artemisinin, its biosynthetic precursors and the biosynthetically related sesquiterpenes was monitored during a vegetation…”
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Isolation and Identification of Dihydroartemisinic Acid Hydroperoxide from Artemisia annua:  A Novel Biosynthetic Precursor of Artemisinin by Wallaart, T. Eelco, Pras, Niesko, Quax, Wim J

“…Dihydroartemisinic acid hydroperoxide (2) was isolated for the first time as a natural product from the plant Artemisia annua in a 29% yield. Its structure was…”
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Isolation and Identification of Dihydroartemisinic Acid from Artemisia annua and Its Possible Role in the Biosynthesis of Artemisinin by Wallaart, T. Eelco, van Uden, Wim, Lubberink, Heidi G. M, Woerdenbag, Herman J, Pras, Niesko, Quax, Wim J

“…Dihydroartemisinic acid (2) was isolated as a natural product from Artemisia annua in a 66% yield, and its structure was confirmed by 1H and 13C NMR…”
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A fast and simple GC MS method for lignan profiling in Anthriscus sylvestris and biosynthetically related Plant species by Koulman, A, Bos, R, Medarde, M, Pras, N, Quax, W J

“…A new GC-MS method for monitoring lignans was developed to study the variation in plants and elucidate the biosynthetic steps. A simple and fast extraction…”
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Cytotoxicity of Artemisinin-Related Endoperoxides to Ehrlich Ascites Tumor Cells by Woerdenbag, Herman J, Moskal, Tamara A, Pras, Niesko, Malingré, Theo M, El-Feraly, Farouk S, Kampinga, Harm H, Konings, Antonius W. T

“…A series of artemisinin-related endoperoxides was tested for cytotoxicity to Ehrlich ascites tumor (EAT) cells using the microculture tetrazolium (MTT) assay…”
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Structure−Cytotoxicity Relationships of Some Helenanolide-Type Sesquiterpene Lactones by Beekman, Aäron C, Woerdenbag, Herman J, van Uden, Wim, Pras, Niesko, Konings, Antonius W. T, Wikström, Håkan V, Schmidt, Thomas J

“…This study deals with the cytotoxicity of helenanolide-type (10α-methylpseudoguaianolide) sesquiterpene lactones. We determined the influence of substitution…”
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Deoxypodophyllotoxin 6-hydroxylase, a cytochrome P450 monooxygenase from cell cultures of Linum flavum involved in the biosynthesis of cytotoxic lignans by MOLOG, Grietje Antje, EMPT, Ursula, KUHLMANN, Stephan, VAN UDEN, Wim, PRAS, Niesko, ALFERMANN, August Wilhelm, PETERSEN, Maike

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Bioconversion of naturally occurring precursors and related synthetic compounds using plant cell cultures by Pras, N

“…The nearly unlimited enzymatic potential of cultured plant cells can basically be employed for bioconversion purposes. Plant enzymes are able to catalyze…”
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Decreasing the load? Is a Multidisciplinary Multistep Medication Review in older people an effective intervention to reduce a patient's Drug Burden Index? Protocol of a randomised controlled trial by van der Meer, Helene G, Wouters, Hans, van Hulten, Rolf, Pras, Niesko, Taxis, Katja

“…IntroductionOlder people often use medications with anticholinergic or sedative side effects which increase the risk of falling and worsen cognitive…”
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Isolation, Purification, and Cytotoxicity of 5-Methoxypodophyllotoxin, a Lignan from a Root Culture of Linum flavum by Van Uden, Wim, Homan, Ben, Woerdenbag, Herman J, Pras, Niesko, Malingré, Theo M, Wichers, Harry J, Harkes, Marien

“…A method has been developed for the large scale isolation of 5-methoxypodophyllotoxin [1] from a high-producing root culture derived from Linum flavum. A…”
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On the improvement of the podophyllotoxin production by phenylpropanoid precursor feeding to cell cultures of Podophyllum hexandrum Royle by Uden, W. van (Groningen Univ. (Netherlands). Univ. Centre for Pharmacy, Lab. for Pharmacognosy), Pras, N, Malingre, T.M

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Determination of valepotriates by Bos, Rein, Woerdenbag, Herman J, Pras, Niesko

“…In this paper an overview is given of qualitative and quantitative methods of analysis used for valepotriates. Methods like spectophotometry, titrimetry, TLC,…”
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Detection and identification ofPodophyllotoxin produced by cell cultures derived from podophyllum hexandrum royle by van Uden, W, Pras, N, Visser, J F, Malingré, T M

“…The phenylpropanoid derived lignan podophyllotoxin, occurring inPodophyllum species, is used as a starting compound for the chemical synthesis of the…”
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Determination of valepotriates: Chromatographic and Electrophoretic Analysis of Secondary Metabolites of Plants by BOS, Rein, WOERDENBAG, Herman J, PRAS, Niesko

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Volatile components from Anthriscus sylvestris (L.) Hoffm by Bos, Rein, Koulman, Albert, Woerdenbag, Herman J, Quax, Wim J, Pras, Niesko

“…The volatile components of fresh leaves and roots from Anthriscus sylvestris (L.) Hoffm., obtained through hydrodistillation, were analysed by GC and GC–MS…”
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Seasonal variations of Artemisinin and its biosynthetic precursors in tetraploid Artemisia annua plants compared with the diploid wild-type by Eelco Wallaart, T, Pras, N, Quax, W J

“…Using colchicine we induced tetraploidy in Artemisia annua L. plants. During a vegetation period we monitored the time course of the levels of artemisinin, its…”
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The bioconversion process of deoxypodophyllotoxin with Linum flavum cell cultures by Koulman, Albert, Beekman, Aäron C, Pras, Niesko, Quax, Wim J

“…The in vitro cell suspension culture of Linum flavum is able to convert high amounts of the 2,7'-cyclolignan deoxypodophyllotoxin into 6-methoxypodophyllotoxin…”
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Artemisinin-derived sesquiterpene lactones as potential antitumour compounds: cytotoxic action against bone marrow and tumour cells by Beekman, A C, Wierenga, P K, Woerdenbag, H J, Van Uden, W, Pras, N, Konings, A W, el-Feraly, F S, Galal, A M, Wikström, H V

“…We determined the in vitro cytotoxic activity of the sesquiterpene lactone endoperoxide artemisinin (1) and some chemically prepared derivatives, which have…”
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Deoxypodophyllotoxin 6-hydroxylase, a cytochrome P450 monooxygenase from cell cultures of Linum flavum involved in the biosynthesis of cytotoxic lignans by Molog, Grietje Antje, Empt, Ursula, Kuhlmann, Stephan, van Uden, Wim, Pras, Niesko, Alfermann, August Wilhelm, Petersen, Maike

“…Cell-suspension cultures of Linum flavum L. (Linaceae) synthesize and accumulate aryltetrahydronaphthalene lignans with 6-methoxypodophyllotoxin as the main…”
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A phytochemical study of lignans in whole plants and cell suspension cultures of Anthriscus sylvestris by Koulman, Albert, Kubbinga, Marlies E, Batterman, Sieb, Woerdenbag, Herman J, Pras, Niesko, Woolley, Jack G, Quax, Wim J

“…In the roots of Anthriscus sylvestris 12 different lignans were detected. Arctigenin, dimethylmatairesinol, dimethylthujaplicatin, podophyllotoxin,…”
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