title: Metabolism of 5'alpha,8'-cycloabscisic acid, a highly potent and long-lasting abscisic acid analogue, in radish seedlings.
abstract: We synthesized 5'alpha,8'-cycloabscisic acid (CycloABA), a highly potent and long-lasting abscisic acid (ABA) analogue, by a different method from that reported before. CycloABA fed to radish seedlings had more metabolic tolerance than ABA. The major metabolite of CycloABA was the glucose conjugate, which was the minor metabolite of ABA. The 8'-hydroxylated metabolite and its cyclized isomer, which were major metabolites of ABA, were not found as metabolites of CycloABA. The present results suggest that the highly potent and long-lasting activity of CycloABA is caused by resistance to ABA 8'-hydroxylase, and that CycloABA is partially metabolized to the glucose conjugate by ABA glucosyltransferase.
authors.affiliation: Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Shizuoka 422-8529, Japan. aytodor@agr.shizuoka.ac.jp
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Todoroki
authors.forename: Masao
authors.initials: M
authors.lastname: Sawada
authors.forename: Miyuki
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Shigeko
authors.initials: S
authors.lastname: Tsukada
authors.forename: Kotomi
authors.initials: K
authors.lastname: Ueno
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Isaka
authors.forename: Mariko
authors.initials: M
authors.lastname: Owaki
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Hirai
mesh_terms: D000040:Abscisic Acid / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000494:pharmacology; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D018525:Germination / Q000187:drug effects; D006899:Mixed Function Oxygenases / Q000378:metabolism; D008967:Molecular Biology / Q000379:methods; D010937:Plant Growth Regulators / Q000378:metabolism; D010940:Plant Proteins; D031224:Raphanus / Q000378:metabolism*; D036226:Seedlings / Q000254:growth & development / Q000378:metabolism; D012639:Seeds / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: C492851:5'alpha,8'-cycloabscisic acid; D010937:Plant Growth Regulators; D010940:Plant Proteins; D000040:Abscisic Acid; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; C107203:abscisic acid 8'-hydroxylase