| Project/Area Number |
63470019
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
天然物有機化学
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| Research Institution | Hokkaido University |
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Principal Investigator |
TAKASUGI Mitsuo Hokkaido University, Faculty of Science, Professor, 理学部, 教授 (70000833)
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| Co-Investigator(Kenkyū-buntansha) |
MONDE Kenji Hokkaido University, Faculty of Science, Instructor, 理学部, 助手 (40210207)
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| Project Period (FY) |
1988 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥7,800,000 (Direct Cost: ¥7,800,000)
Fiscal Year 1990: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1989: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1988: ¥4,700,000 (Direct Cost: ¥4,700,000)
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| Keywords | Crucifer / Phytoalexin / Sulfur compound / Indole / Biosynthesis / biologically active compound / Glucosinolate / Isothiocyanate / 含硫化合物 / イソチオシアナ-ト / カブ / キャベツ / HPLC分析 / アブラナ科 / ハクサイ / ダイコン / ハクラン / イオウ原子 |
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| Research Abstract |
(1) Several sulfur-containing phytoalexins have been isolated from cruciferous vegetables ; Chinese cabbage, cabbage, radish, and turnip. These phytoalexins, represented by brassinin, cyclobrassinin, and spirobrassinin, are characterized by the presence of indolic nucleus with the appendage containigone or two sulfur atoms.
(2) Time-course studies of cruciferous phytoalexins and glucosinolates have been carried out using UV-irradiated and non-irradiated turnip root tissues. Both of the levels of indole glucosinolates and phytoalexins increased in the UV-irradiated tissue whereas only the former did in non-irradiated control tissue. The levels of aliphatic glucosinolates decreased markedly both in the UV-irradiated and non-irradiated control tissues. Structural features of brassinins and indple glucosinolates suggest close biosynthetic relationships between two types of indoles. Additional parhway seems to be needed to induce the synthesis of phytoalexns.
(3) Biosynthetic pathway to cruciferous phytoalexins was investigated using UV-irradiated turnip and deuterium- or ^<13> C-labeled precursors : Tryptophan is a biological origin of the indole ring ; methyl portion of the methyothio groups of these phytoalexins originates from methionine ; molecular rearrangement would be involved in the pathway from tryprophan to brassinin ; transformation of benzyl isothiocyanate into brassinin-type compound in the tissue suggests that indo1-3-ylmethyl isothiocyanate, synthesized via indole glucosinolate or directly from tryptophan, would be a key intermediate in the biosynthesis of brassinin.
(4) Administration of artificial 2-methylbrassinin into UV-irradiated tissue resulted in the formation of an indoxyl and an indolenine derivative, suggesting 3-hydroxyindolenine or 2, 3-dihydroxyindole as a common intermediate to cyclobrassinin, dioxibrassinin, and spirobrassinin.
(5) A biosynthetic scheme starting from tryptophan to cruciferous phytoalexins is proposed.
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