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Chemical Structures and Chemical Modification of Condensed Tannin.

缩合单宁的化学结构和化学改性。

基本信息

批准号：
03660170
负责人：
ABE Isao
金额：
$ 1.34万
依托单位：
Mie University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

1. Chemical Analysis and Characteristics of Condensed Tannins. Appropriate compositions of the phenyl Nucleus-Exchange (NE) reagent, reaction temperature and the time were selected to evaluate the characteristics or the phenolic patterns of condensed tannins. Furthermore, the necessary care to be taken on determining the purity and the phenolic characteristics by the NE method were discussed by the use of a flavonol dimer isolated from Quebracho tannin. After then, Karamatsu barks extractives by the successive extraction were characterized, compared with Wattle and Quebracho tannins. The results obtained by the NE-method and the other analytical method indicated that the outer bark contained about twice of the extractives by weight, but involved the more amount of the destructive A-rings than the inner bark.2. Mechanisms of the Phenolation and the NE-reaction for a Monomeric Model. The behavior of the phenolation and the NE-reaction in the phenol -BF_3 system for (+)-catechin was followed and further, three compounds formed during the reaction were isolated and identified. From the results, we discussed the mechanisms of the phenolation and the NE- reaction, and recognized the formation of the ring opening and phenolated flexible compound under the mild reaction conditions, indicating the convertible possibility of rigid structure of tannins to the flexible polyvalent phenol-polymers by the phenolation.3. Chemical Modification of Condensed Tannin. In order to convert the rigid tannin molecules into the flexible and more uniform nucleophilic phenol-polymer by the phenolation, the effects of a kind of phenolic medium and the added amount of acid catalyst on the behavior of the phenolation were examined. The selective condition was 100g of resorcinol and 0.05mols of H_2SO_4, and 120C-2hrs. The rate of ionization and the reaction with a nucleophilic reagent of phenolized tannin obtained by such the conditions was much faster than that of original tannin preparation.

1. 缩合单宁的化学分析与特性。选择合适的苯基核交换试剂的组成、反应温度和反应时间来评价缩合单宁的酚化特征。此外，本文还讨论了用单宁黄酮醇二聚体测定NE法纯度和酚类物质特性时应注意的问题。然后，对连续提取的卡拉松树皮提取物进行了表征，并与金合欢和凤尾花的单宁进行了比较。ne - 1法和其他分析方法的结果表明，外皮的提取物含量约为其重量的两倍，但破坏性a环的含量高于内皮。单体模型的酚化反应和ne -反应机理。研究了苯酚-BF_3体系中(+)-儿茶素的酚化反应和ne -反应行为，并分离鉴定了三种反应生成的化合物。从结果上讨论了酚化反应和NE-反应的机理，发现在温和反应条件下可形成开环和酚化柔性化合物，表明单宁的刚性结构有可能通过酚化反应转化为柔性多价苯酚聚合物。缩合单宁的化学改性。为了将刚性单宁分子通过酚醛化反应转化为柔性且更均匀的亲核酚醛聚合物，研究了一种酚醛介质和酸催化剂的添加量对酚醛化反应行为的影响。选择条件为间苯二酚100g， H_2SO_4 0.05mol，温度为120c -2h。在此条件下制备的酚化单宁的电离速度和与亲核试剂的反应速度都比原始单宁制备的快得多。