Abstract (+)-Catechin oxidation was carried out in aqueous systems using grapepolyphenoloxidase as catalyst. Eight fractions corresponding to the major products formed at pH 3 and 6 were purified using HPLC at the preparative and semi-preparative scale. Structural characterization using UV-visible detection and mass spectrometry indicated that they corresponded to (+)-catechindimers including two
摘要 以葡萄多酚氧化酶为催化剂,在水性体系中进行(+)-儿茶素氧化。对应于在 pH 3 和 6 下形成的主要产物的八个级分使用 HPLC 以制备和半制备规模进行纯化。使用紫外-可见光检测和质谱的结构表征表明它们对应于 (+)-儿茶素二聚体,包括两种黄色颜料。单维和二维 1H 和 13C NMR 分析提供了五种氧化产物的结构假设,而其他三个部分是几种异构体的混合物。具有 CC 或 CO 间黄烷键的无色产品是 B 型脱氢二苯酚。两种色素中的一种对应于脱氢二甲双胍 A,已在其他氧化模型中确定,
Lipase Inhibitors
申请人:Nakai Masaaki
公开号:US20080317821A1
公开(公告)日:2008-12-25
The present invention provides lipase inhibitors containing dimers of flavan-3-ols derived from teas as well as foods and beverages and medicines containing said inhibitors. More specifically, the present invention provides lipase inhibitors containing at least one of assamicains represented by the formula:
wherein G represents a galloyl group;
theasinensins represented by the formula:
wherein R
1
represents G or H, and R
2
represents G; and
theaflavins represented by the formula: