title: A specific and potent inhibitor of brassinosteroid biosynthesis possessing a dioxolane ring.
abstract: Screening for brassinosteroid biosynthesis inhibitors was performed to find azole derivatives that induced dwarfism, to resemble brassinosteroid-deficient mutants in Arabidopsis, and which could be rescued by brassinosteroid. Through this screening experiment, propiconazole fungicide was selected as a likely inhibitor of brassinosteroid biosynthesis and, thus, propiconazole derivatives with optimized activity and selectivity were synthesized. The biological activity of these compounds was evaluated by examining cress stem elongation. Among the compounds tested, 2RS,4RS-1-[2-(4-trifluoromethylphenyl)-4-n-propyl-1,3-dioxolan-2-ylmethyl]-1H-1,2,4-triazole (12) showed the most potent capability to retard cress stem elongation in the light. The compound-induced hypocotyl dwarfism was restored by the coapplication of 10 nM brassinolide but not by 1 microM gibberellin. These results suggest that 12 should affect brassinosteroid biosynthesis. The potency and specificity of 12 were greater than those of brassinazole, a previously reported brassinosteroid biosynthesis inhibitor.
authors.affiliation: Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Sekimata
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Han
authors.forename: Koichi
authors.initials: K
authors.lastname: Yoneyama
authors.forename: Yasutomo
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yoshida
authors.forename: Tadao
authors.initials: T
authors.lastname: Asami
mesh_terms: D060406:Brassinosteroids; D002777:Cholestanols / Q000494:pharmacology; D065607:Cytochrome P-450 Enzyme Inhibitors; D004149:Dioxoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D005875:Gibberellins / Q000037:antagonists & inhibitors*; D013260:Steroids, Heterocyclic / Q000494:pharmacology; D014230:Triazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology
chemical_list: C459439:1-(2-(4-trifluoromethylphenyl)-4-n-propyl-1,3-dioxolan-2-ylmethyl)-1H-1,2,4-triazole; D060406:Brassinosteroids; C451122:Brz2001; D002777:Cholestanols; D065607:Cytochrome P-450 Enzyme Inhibitors; D004149:Dioxoles; D005875:Gibberellins; D013260:Steroids, Heterocyclic; D014230:Triazoles; C045950:propiconazole; C412342:brassinazole; C023623:brassinolide