- EFFECT ON ERGOSTEROL BIOSYNTHESIS OF A FUNGICIDE, SSF-109, IN BOTRYTIS CINEREA
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Treatment of Botrytis cinerea with a novel fungicide SSF-109, (dl)-cis-1-(4-chlorophenyl)-2-(1H-1,2,4-triazol-1-yl)cyclo-heptanol (0.45 μg ml-1), gave five 14α-methyl sterols, 24-methylene-24(25)-dihydrolanosterol, 24-methylene-24(25)-dihydrolanosten-3-one, obtusifoliol, obtusifolione, and 14α-methylfecosterol, together with ergosterol and ergosta-5,8,22-trien-3β-ol.SSF-109 was found to inhibit the biosynthesis of ergosterol at the 14α-demethylation step.
- Shirane, Noboru,Murabayashi, Akira,Masuko, Michio,Uomori, Atsuko,Yoshimura, Yohko,et al.
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p. 2513 - 2520
(2007/10/02)
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- 7-OXO-24ξ(28)-DIHYDROCYCLOEUCALENOL, A POTENT INHIBITOR OF PLANT STEROL BIOSYNTHESIS
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Cycloeucalenol-obtusifoliol isomerase from higher plant cells catalyses the opening of the cyclopropane ring of cycloeucalenol yielding obtusifoliol. 7-Oxo-24ξ(28)-dihydrocycloeucalenol was not a substrate but behaved like a potent inhibitor of the isomerase.The inhibition was reversible and highly specific; the inhibitor needed the presence of the 7-oxo group, the cyclopropane ring and the absence of a 4β-methyl group to be active.Other enzymes involved in plant sterol biosynthesis such as 2,3-oxidosqualene-cycloartenol cyclase and S-adenosyl methionine cycloartenol C-24 methyltransferase were not inhbited by 7-oxo-24ξ(28)-dihydrocycloeucalenol.In vivo treatment of a suspension of bramble cells growing in a liquid medium with 7-oxo-24ξ(28)-dihydrocycloeucalenol resulted in a strong accumulation of 9β,19-cyclopropyl sterols confirming that the main cellular target of the inhibitor is the cycloeucalenol-obtusfoliol isomerase.Key Word Index - Zea mays; Gramineae; Rubus fruticosus; Rosaceae; plant sterol biosynthesis inhibitors; cycloeucalenol-obtusifoliol isomerase; 7-oxo-24ξ(28)-dihydrocycloeucalenol; cellular and enzymatic targets at 7-oxo-24ξ(28)-dihydrocycloeucalenol.
- Rahier, Alain,Schmitt, Paulette,Benveniste, Pierre
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p. 1969 - 1974
(2007/10/02)
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