title: Conversions of deoxyradicinin to radicinin and of radicinin to 3-epi-radicinin in the phytopathogenic fungus Bipolaris coicis.
abstract: Radicinin is a phytotoxic and antibiotic metabolite produced by some phytopathogenic fungi. Precursor administration and cell-free experiments with deoxyradicinin and radicinin were carried out in Bipolaris coicis H13-3. When deoxyradicinin was administered to the fungus, radicinin and 3-epi-radicinin formed. When radicinin administered, 3-epi-radicinin was formed. Their formation was confirmed by cell-free experiments. Deoxyradicinin 3-monooxygenase which catalyzes conversion of deoxyradicinin to radicinin showed the best activity at 35 °C and pH 7.0, and required NAD+ as co-enzyme. Its molecular weight was determined to be 130-184 kDa. Radicinin epimerase catalyzing the reaction of radicinin to 3-epi-radicinin was purified from a cell-free extract. Radicinin epimerase is a homodimer of a 28 kDa subunit, and its highest activity was achieved at 30-35 °C and pH 7.0-9.0.
authors.affiliation: Department of Agricultural Chemistry, Faculty of Agriculture, Tottori University Koyama, Tottori 680-8553, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Suzuki
authors.forename: Emi
authors.initials: E
authors.lastname: Sakuno
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ishihara
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Tamura
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Nakajima
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005658:Fungi / Q000737:chemistry / Q000145:classification / Q000378:metabolism*; D008968:Molecular Conformation; D010802:Phylogeny; D011753:Pyrones / Q000737:chemistry / Q000378:metabolism*
chemical_list: C572285:3-epi-radicinin; D011753:Pyrones; C009157:radicinin; C572284:deoxyradicinin