| Project/Area Number |
03660136
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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 | KYOTO UNIVERSITY |
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Principal Investigator |
HIRAI Nobuhiro Kyoto Univ. Fac. of Agriculture Instructor, 農学部, 助手 (00165151)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1992: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1991: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Abscisic acid / Phaseic acid / Metabolism / Fluorination / Methoxyabscisic acid / Fluoroabscisic acid / 8'ーヒドロキシアブシジン酸 / 8'ーメトキシアブシジン酸 / 植物生長阻害物質 |
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| Research Abstract |
Abscisic acid (ABA) is deactivated by hydroxylation at C-8' followed by cyclization to phaseic acid in plants. Introduction of methoxy or fluorine to C-8' and 9' was planned to increase the activity through prevention against the deactivation.
(*)-8'- and 9'-Methoxy derivatives were synthesized from hydroxymethyldimethylcyclohexanone, and optically resolved by HPLC with a Chiralpak AD column. (+)-8'-MethoxyABA was three times as active as (+)-ABA in a rice seedling test. The activity of (+)-9'-methoxyABA was ten times and twice higher than that of (+)-ABA in lettuce seeds and alpha-amylase induction tests, respectively. These methoxy derivatives are first analogs with higher activity than ABA. The high activity of 9'-methoxyABA suggests that the methoxy group at C-9' affects the affinity to receptor rather than metabolism. The activity of (-) forms were 1/10-1/400 of (+) forms. The difference of activity between (+) and (-) forms was larger than that in the case of ABA, supporting that methoxyABA might have higher affinity to receptor than ABA.
Fluorination of hydroxymethyldimethylcyclohexanone and its aldehyde was tried with DAST. Monofluorination of the alcohol was difficult, but achieved in a yield of 30% from the cis dimethyl form. Difluorinated precursor was obtained in a yield of 40% from the aldehyde. Synthesis of monofluoro and difluoro-ABA is under progress. Biological activity of these derivatives will be tested.
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