Výsledky vyhledávání - "Gerard H. L. Nefkens"

Dose−Response of Seeds of the Parasitic WeedsStrigaandOrobanchetoward the Synthetic Germination Stimulants GR 24 and Nijmegen 1

Autor: Gerard H. L. Nefkens, Suzanne C. M. Wigchert, G. J. Boelhouwer, J. A. C. Verkleij, E. Kuiper, Binne Zwanenburg

Publikováno v: Journal of Agricultural and Food Chemistry. 47:1705-1710

Striga and Orobanche seeds germinate in response to a host-derived germination stimulant. Dose−response curves of the synthetic strigolactone analogues GR 24 and Nijmegen 1 were determined, and their activities were compared to that of the naturall

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7378f3b6f484c3cc16af849649450399
https://doi.org/10.1021/jf981006z

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Asymmetric Synthesis of All Stereoisomers of the Strigol Analogue GR24. Dependence of Absolute Configuration on Stimulatory Activity of Striga hermonthica and Orobanche crenata Seed Germination

Autor: Gerard H. L. Nefkens, Jan Willem J. F. Thuring, Binne Zwanenburg

Publikováno v: Journal of Agricultural and Food Chemistry. 45:2278-2283

All four optically pure stereoisomers of the strigol analogue GR24 were prepared via two different routes. In the first approach enantiopure ABC-fragments 4 were used as the chiral source, whereas in the alternative route both antipodes of the latent

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::7cb7cde34fd03e47606d704b27a634b3
https://doi.org/10.1021/jf960466u

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Synthesis of a Phthaloylglycine-Derived Strigol Analogue and Its Germination Stimulatory Activity toward Seeds of the Parasitic Weeds Striga hermonthica and Orobanche crenata

Autor: Jan Willem J. F. Thuring, Binne Zwanenburg, Gerard H. L. Nefkens, Marco F. M. Beenakkers

Publikováno v: Journal of Agricultural and Food Chemistry. 45:2273-2277

The newly designed strigol analogue Nijmegen 1 (rac 7) was prepared in high overall yield starting from N-phthaloylglycine. This relatively simple analogue exhibits high bioactivity in the stimulation of germination of seeds of the parasitic weeds St

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::31e8a7f802ebf83ca9f8d459c8f32480
https://doi.org/10.1021/jf9604504

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Synthesis and Biological Evaluation of the Strigol Analogue Carba-GR24

Autor: Gerard H. L. Nefkens, Binne Zwanenburg, Jan Willem J. F. Thuring

Publikováno v: Journal of Agricultural and Food Chemistry. 45:1409-1414

Both geometrical isomers of the strigol analogue carba-GR24, (E)-3-[2-(4-methyl-5-oxo-2,5-dihydrofuran-2-yl)ethylidene]-3,3a,4,8b-tetrahydro-2H-indeno[1,2-b]furan-2-one (1) and 7 (Z isomer), were prepared separately. These analogues, in which the vin

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::dbac59e5c34a4d6c0f95ee4e5f48270b
https://doi.org/10.1021/jf960443f

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Asymmetric Synthesis of All Stereoisomers of Demethylsorgolactone. Dependence of the Stimulatory Activity of Striga hermonthica and Orobanche crenata Seed Germination on the Absolute Configuration

Autor: Jan Willem J. F. Thuring, Robèrt W. A. W. M. Jacobs, Gerard H. L. Nefkens, Nicole W. J. T. Heinsman, Binne Zwanenburg

Publikováno v: Journal of Agricultural and Food Chemistry. 45:507-513

Strigol and sorgolactone belong to the class of “strigolactones”, which are highly potent germination stimulants of seeds of the parasitic weeds Striga and Orobanche. The aim of the present work was to synthesize all four stereoisomers of demethy

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https://doi.org/10.1021/jf9605106

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Synthesis and biological evaluation of strigol analogues modified in the enol ether part

Autor: Jan Willem, J. F. Thuring, Angelique A. M. A. van Gaal, Sander J. Hornes, Margreet M. de Kok, Gerard H. L. Nefkens, Binne Zwanenburg

Publikováno v: Journal of the Chemical Society, Perkin Transactions 1. :767-774

Several analogues of strigol, which is a germination stimulant for seeds of the parasitic weeds Striga and Orobanche, have been prepared. Structural modifications are introduced in the vinyl ether part and include: i, analogues containing an endocycl

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::c41208b69e75ff38eae08c095d9d533b
https://doi.org/10.1039/a604852h

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Enzymatic Kinetic Resolution of 5-Hydroxy-4-oxa-endo-tricyclo[5.2.1.02,6]dec-8-en-3-ones: A Useful Approach to D-Ring Synthons for Strigol Analogues with Remarkable Stereoselectivity

Autor: Binne Zwanenburg, A. J. H. Klunder, Gerard H. L. Nefkens, Margreth A. Wegman, Jan Willem J. F. Thuring

Publikováno v: The Journal of Organic Chemistry. 61:6931-6935

Racemic 5-hydroxy-4-oxa-endo-tricyclo[5.2.1.0(2,6)]dec-8-en-3-one and its 2-methyl analogue were resolved employing a lipase-catalyzed acetylation reaction. The latter compound thus gave access to a homochiral D-ring synthon for strigolactones. The e

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c92596adf6b15aae822c6d3f6e952dbd
https://doi.org/10.1021/jo9610220

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Asymmetric synthesis of a D-ring synthon for strigol analogues and its application to the synthesis of all four stereoisomers of germination stimulant GR7

Autor: Gerard H. L. Nefkens, Robert Schaafstra, Jan Willem J. F. Thuring, Binne Zwanenburg

Publikováno v: Tetrahedron. 51:5047-5056

A novel asymmetric synthesis of the strigol analogue GR7 has been developed. The olefinic double bond of the butenolide D-ring was protected as a Diels-Alder adduct with cyclopentadiene. The thus obtained tricyclic compound was resolved and transform

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::9534133a4bbb4a193de28b839394afe6
https://doi.org/10.1016/0040-4020(95)98701-i

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