ChemInform Abstract: Stereoselective Synthesis of Plant Growth‐promoting Steroids, Brassinolide, Castasterone, Typhasterol, and Their 28‐Nor Analogues.

Takatsuto, Suguru; Yazawa, Naoto; Ishiguro, Masaji; Morisaki, Masuo; Ikekawa, Nobuo

doi:10.1002/chin.198420291

Cited by 4 publications

(6 citation statements)

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“…The 1 H-and 13 C-NMR spectroscopic data of diol 11 were consistent with those reported [8,32]. In addition, the spatial orientations of Compound 11 was obtained with 51% yield by stereospecific α-face hydroxylation of olefin 10 using a catalytic amount of osmium tetraoxide (4.0%) in a mixture of (CH 3 ) 2 CO-H 2 O (3:1) and 2.0 mL of pyridine, and in the presence of N-methylmorpholine N-oxide [33]. The 1 H-and 13 C-NMR spectroscopic data of diol 11 were consistent with those reported [8,32].…”

Section: Resultssupporting

confidence: 85%

“…Both signals were assigned from the 2D HMBC spectrum, where the H-3 (δH = 5.69-5.66 ppm, m, 1H) showed 3 JH-C correlation with C-1 (δC = 39.34 ppm) and 2 JH-C with C-4 (δC = 27.88 ppm), while H-2 (δH = 5.57-5.55 ppm, m, 1H) showed 3 JH-C correlation with C-4 (δC = 27.88 ppm) and 2 JH-C with C-1 (δC = 39.34 ppm). Compound 11 was obtained with 51% yield by stereospecific α-face hydroxylation of olefin 10 using a catalytic amount of osmium tetraoxide (4.0%) in a mixture of (CH3)2CO-H2O (3:1) and 2.0 mL of pyridine, and in the presence of N-methylmorpholine N-oxide [33]. The 1 H-and 13 C-NMR spectroscopic data of diol 11 were consistent with those reported [8,32].…”

Section: Resultssupporting

confidence: 82%

“…1H) and CH3-SO2-(s, 3H), respectively, whereas in the 13 C-NMR spectrum, a signal corresponding to CH3-SO2 was observed at δC = 38.38 ppm. Subsequent treatment of compound 9 with the Li2CO3/LiBr system at 80 °C in dimethylformamide (DMF) produces the alquene 10 with 74.9% yield [33] (Scheme 2). The 1 H-NMR spectroscopic data of alquene 10 was consistent with that previously reported [8,32].…”

Section: Resultsmentioning

confidence: 99%

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Structural Modifications of Deoxycholic Acid to Obtain Three Known Brassinosteroid Analogues and Full NMR Spectroscopic Characterization

et al. 2016

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An improved synthesis route for obtaining known brassinosteroid analogues, i.e., methyl 2α,3α-dihydroxy-6-oxo-5α-cholan-24-oate (11), methyl 3α-hydroxy-6-oxo-7-oxa-5α-cholan-24-oate (15) and methyl 3α-hydroxy-6-oxa-7-oxo-5α-cholan-24-oate (16), from hyodeoxycholic acid (4) maintaining the native side chain is described. In the alternative procedure, the di-oxidized product 6, obtained in the oxidation of methyl hyodeoxycholate 5, was converted almost quantitatively into the target monoketone 7 by stereoselective reduction with NaBH 4 , increasing the overall yield of this synthetic route to 96.8%. The complete 1 H-and 13 C-NMR assignments for all compounds synthesized in this work have been made by 1D and 2D heteronuclear correlation gs-HSQC and gs-HMBC techniques. Thus, it was possible to update the spectroscopic information of 1 H-NMR and to accomplish a complete assignment of all 13 C-NMR signals for analogues 5-16, which were previously reported only in partial form.

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Section: Resultssupporting

confidence: 85%

Section: Resultssupporting

confidence: 82%

Section: Resultsmentioning

confidence: 99%

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Structural Modifications of Deoxycholic Acid to Obtain Three Known Brassinosteroid Analogues and Full NMR Spectroscopic Characterization

et al. 2016

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“…Other intermediates in the BR biosynthesis pathway used in this report were synthesized as described previously (Takatsuto et al, 1984;Takatsuto, 1986;Fujioka et al, 1995). Murashige and Skoog salt and vitamin mixture was purchased from Gibco-BRL (Grand Island, NY).…”

Section: Chemicalsmentioning

confidence: 99%

Characterization of Brassinazole, a Triazole-Type Brassinosteroid Biosynthesis Inhibitor

et al. 2000

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Screening for brassinosteroid (BR) biosynthesis inhibitors was performed to find chemicals that induce dwarfism in Arabidopsis, mutants that resembled BR biosynthesis mutants that can be rescued by BR. Through this screening experiment, the compound brassinazole was selected as the most potent chemical. In dark-grown Arabidopsis, brassinazoleinduced morphological changes were nearly restored to those of wild type by treatment with brassinolide. The structure of brassinazole is similar to pacrobutrazol, a gibberellin biosynthesis inhibitor. However, in assays with cress (Lepidium sativum) plants, brassinazole-treated plants did not show recovery after the addition of gibberellin but showed good recovery after the addition of brassinolide. These data demonstrate that brassinazole is a specific BR biosynthesis inhibitor. Brassinazole-treated cress also showed dwarfism, with altered leaf morphology, including the downward curling and dark green color typical of Arabidopsis BR-deficient mutants, and this dwarfism was reversed by the application of 10 nm brassinolide. This result suggests that BRs are essential for plant growth, and that brassinazole can be used to clarify the function of BRs in plants as a complement to BR-deficient mutants. The brassinazole action site was also investigated by feeding BR biosynthesis intermediates to cress grown in the light.

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“…Brassinolide (BL) and castasterone were purchased from CIDtech Research Inc. (Cambridge, ON, Canada). The other intermediates in the BR-biosynthesis pathway used in this report were synthesized as described previously [23][24][25].…”

Section: Chemicalsmentioning

confidence: 99%

Triadimefon, a fungicidal triazole-type P450 inhibitor, induces brassinosteroid deficiency-like phenotypes in plants and binds to DWF4 protein in the brassinosteroid biosynthesis pathway

Asami

Mizutani

Shimada

et al. 2003

Biochemical Journal

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Triadimefon (Bayleton), a widely used triazole-type fungicide, affects gibberellin (GA) biosynthesis and 14 alpha-demethylase in sterol biosynthesis. The present study revealed that the phenotype of Arabidopsis treated with triadimefon resembled that of a brassinosteroid (BR)-biosynthesis mutant, and that the phenotype was rescued by brassinolide (BL), the most active BR, partly rescued by GA, and fully rescued by the co-application of BL and GA, suggesting that triadimefon affects both BR and GA biosynthesis. The target sites of triadimefon were investigated using a rescue experiment, feeding triadimefon-treated Arabidopsis BR-biosynthesis intermediates, and a binding assay to expressed DWF4 protein, which is reported to be involved in the BR-biosynthesis pathway. The binding assay indicated that the dissociation constant for triadimefon was in good agreement with the activity in an in planta assay. In the triadimefon-treated Arabidopsis cells, the CPD gene in the BR-biosynthesis pathway was up-regulated, probably due to feedback regulation caused by BR deficiency. These results strongly suggest that triadimefon inhibits the reaction catalysed by DWF4 protein and induces BR deficiency in plants. As triadimefon treatment has proved to be beneficial to plants, this result suggests that BR-biosynthesis inhibitors can be applied to crops.

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ChemInform Abstract: Stereoselective Synthesis of Plant Growth‐promoting Steroids, Brassinolide, Castasterone, Typhasterol, and Their 28‐Nor Analogues.

Abstract: Die Synthese der Titelverbindungen (Xa) (Castasteron), (Xb) (Brassinon), (XIc) (Brassinolid), (XId) (Norbrassinolid) bzw. Typhasterol (XIII) geht vom Aldehyd (I) aus, der zunächst über die angegebenen Stufen in das Steroid (VId) übergeführt wird.

Cited by 4 publications

References 1 publication

Structural Modifications of Deoxycholic Acid to Obtain Three Known Brassinosteroid Analogues and Full NMR Spectroscopic Characterization

Structural Modifications of Deoxycholic Acid to Obtain Three Known Brassinosteroid Analogues and Full NMR Spectroscopic Characterization

Characterization of Brassinazole, a Triazole-Type Brassinosteroid Biosynthesis Inhibitor

Triadimefon, a fungicidal triazole-type P450 inhibitor, induces brassinosteroid deficiency-like phenotypes in plants and binds to DWF4 protein in the brassinosteroid biosynthesis pathway

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