2000 Fiscal Year Final Research Report Summary
Urethane formation from condensed tannins and biodegradability of the urethane
| Project/Area Number |
10460145
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
生物資源科学
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
SAKAI Kokki KYUSHU UNIVERSITY, Faculty of Agriculture, Prof., 大学院・農学研究院, 教授 (30015656)
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| Co-Investigator(Kenkyū-buntansha) |
FUJITA Koki KYUSHU UNIVERSITY, Faculty of Agriculture, Assist.Prof., 大学院・農学研究院, 助手 (90264100)
KONDO Ryuichiro KYUSHU UNIVERSITY, Faculty of Agriculture, Assoc.Prof., 大学院・農学研究院, 教授 (80091370)
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| Project Period (FY) |
1998 – 2000
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| Keywords | condensed tannin / model compound / sugi bark / catechin / urethane formation / amine catalyst / dibutyl tin catalyst / hydroxyl group value |
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| Research Abstract |
(1) Simple tannin model compounds were treated with an equivalent phenyl isocyanate (PI) in the presence of DABCO (1,4-diazabicyclo[2,2,2]octane) or DBTDL (di-n-butyltin dilaurate) as a catalyst. It was found that DABCO catalyzed urethane formation from catechol-and resorcinol-types of hydroxyl groups, while DBTDL catalyzed that from alcoholic hydroxyl groups.
(2) PI reacted firstly with the hydroxyl groups in ring B and then with those in ring A of catechin, which was employed as a more relevant model, in the presence of DABCO catalyst, while hydroxyl groups in the position 3 of catechin did not react at all. On the contrary, reactivity of catechin with PI was dramatically suppressed in the presence of DBTDL catalyst, due to the formation of a dibutyltin-catechin complex, which precipitated and hence deactivated catechin.
(3) In order to liquefy sugi bark, a treatment with sodium bisulfite in an aqueous polyethylene glycol 400 was conducted. Both inner and outer bark liquefied extensively by the treatment at 250℃. At least a part of condensed tannin was degraded to monocyclic aromatic compounds like catechol and protocaechuic acid. A new method of hydroxyl group determination was developed.
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Research Products
(14 results)
