Studies on Fungal Metabolism of Phytoalexins
| Project/Area Number |
63560116
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
製造化学・食品
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| Research Institution | Hokkaido University |
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Principal Investigator |
TAHARA Satoshi Hokkaido University, Faculty of Agriculture Associate Professor, 農学部, 助教授 (50001475)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1989: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1988: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Phytoalexin / Fungal Metabolism / Antifungal Compound / Prenylated Isoflavone / Isoflavonoid / Leguminosae / Botrytis cinerea / Epoxy-intermediate / ファイトアレキシンの代謝 / プレニルイソフラボン / 微生物代謝 / 植物由来抗菌物質 / 解毒代謝 / 防御物質 |
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| Research Abstract |
Fungal metabolism of phytoalexins was investigated by using prenylated isoflavones and related compounds as substrates, and Botrytis cinerea and Aspergillus flavus. Research results are summarized as follows. (1) 7-O-Methyl-luteone (1) and 7-O-Methyl-2,3-dehydrokievitone (2) both chemically derivated from the corresponding isoflavones, topazolin (3) isolated from Lupinus luteus and piscidone from the root barks of Piscidia erythrina were metabolized by two fungi. A 6-prenylated flavone 3 was metabolized as 6-prenylated isoflavone had been. The prenyl group at C-6' in 4 was successfully transformed into the corresponding cyclic ether by B. cinerea. (2) The major metabolite from 1 was confirmed to be 2,2-dimethyl-3-hydroxypyranoisoflavone with dextrorotatory nature. The stereochemistry was estimated to be S-configuration. (3) Compound 2 was rapidly metabolized not by A. flavus, but by B. cinerea to yield an epoxy-derivative at the double bond in the prenyl side chain and a glycol. The latter metabolite revealed to be S-isomer with which the acid hydrolyzate (stereo-retention) of the epoxide agreed well. Therefore the configuration of the epoxy-intermediate was confirmed to be S. The presence of an epoxy-intermediate in the metabolism of a prenylated compound into a dihydrofurano- or dihydropyrano-cyclic ether and/or a 2,3-dihydrodihydroxy- prenyl derivative was thus confirmed for the first time.
Isoflavonoidal constituents in white lupin (L. albus) were precisely examined and the structures of complex lupin isoflavones suggested that they were presumably produced from prenylated isoflavones via epoxy-intermediates. The biogenedis for lupin isoflavones was thus closely related to their fungal metabolism.
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Report
(3 results)
Research Products
(30 results)
