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Daiki Honma Motoyuki Tagashira Tomomasa Kanda Mari Maeda‐Yamamoto 《Journal of the science of food and agriculture》2010,90(1):168-174
BACKGROUND: Tea (Camellia sinensis L.) is consumed all over the world and in especially large quantities in Japan and China, where it has been used not only as a daily beverage but also for medicinal purposes for thousands of years. Tea has been found to exhibit various bioregulatory activities, including antiallergic, anticarcinogenic, antimetastatic, antioxidative, antihypertensive, antihypercholesterolemic, anti‐dental caries and antibacterial effects, and to influence intestinal flora. RESULTS: Cha Chuukanbohon Nou 6 is a tea cultivar improved by the National Institute of Vegetable and Tea Science (NIVTS) in Japan. On comparing chemical constituents of 11 varieties of tea leaves by high‐performance liquid chromatography, we found two new major compounds in Cha Chuukanbohon Nou 6. Nuclear magnetic resonance spectroscopy revealed these compounds to be theogallin and 1,2‐di‐O‐galloyl‐4,6‐O‐(S)‐hexahydroxydiphenoyl‐β‐D ‐glucopyranose. The two were similar in chemical structure to strictinin, an inhibitor of immunoglobulin (Ig) production. Thus their effects on the production of Igs by peripheral blood lymphocytes were tested. Both compounds, like strictinin, inhibited IgE production. CONCLUSION: The results suggest Cha Chuukanbohon Nou 6 to be the basis of an antiallergic beverage. Copyright © 2009 Society of Chemical Industry 相似文献
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D-葡萄糖五乙酸酯是非常重要的糖类衍生物,在二氧化碳吸附、医药、精细化工和石油化工等领域用途广泛,关于D-葡萄糖五乙酸酯的合成、产物构型转化与控制是其热点研究方向。本文综述了D-葡萄糖五乙酸酯的催化合成研究进展,主要介绍了均相催化、固体酸催化、酶催化等方法合成D-葡萄糖五乙酸酯的研究情况,重点叙述了吡啶和乙酸钠等碱性催化剂、质子酸和路易斯酸等酸性催化剂、沸石分子筛和杂多酸等固体酸催化剂在D-葡萄糖五乙酸酯合成中的应用情况,指出开发催化活性高、选择性高、构型可调控的催化剂,并将其用于糖类化合物的酯化反应是未来重点研究的方向。 相似文献
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Andrew GregoryMartina H. Stenzel 《Progress in Polymer Science》2012,37(1):38-105
Reversible addition fragmentation chain transfer (RAFT) polymerization has made a huge impact in macromolecular design. The first block copolymers were described early on, followed by star polymers and then graft polymers. In the last five years, the types of architectures available have become more and more complex. Star and graft polymers now have block structures within their branches, or a range of different branches can be found growing from one core or backbone. Even the synthesis of hyperbranched polymers can be positively influenced by RAFT polymerization, allowing end group control or control over the branching density. The creative combination of RAFT polymerization with other polymerization techniques, such as ATRP or ring-opening polymerization, has extended the array of available architectures. In addition, dendrimers were incorporated either as star core or endfunctionalities. A range of synthetic chemistry pathways have been utilized and combined with polymer chemistry, pathways such as ‘click chemistry’. These combinations have allowed the creation of novel structures. RAFT processes have been combined with natural polymers and other naturally occurring building blocks, including carbohydrates, polysaccharides, cyclodextrins, proteins and peptides. The result from the intertwining of natural and synthetic materials has resulted in the formation of hybrid biopolymers. Following these developments over the last few years, it is remarkable to see that RAFT polymerization has grown from a lab curiosity to a polymerization tool that is now been used with confidence in material design. Most of the described synthetic procedures in the literature in recent years, which incorporate RAFT polymerization, have been undertaken in order to design advanced materials. 相似文献
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合成了一种含硫、氮希佛碱配体——水杨醛缩 N- 氨基 - N′- 2 ,3,4,6- 四 - O- 乙酰基 - β- D- 吡喃葡萄糖基硫脲及其与 Cu2 + 的配合物。并通过元素分析、红外光谱、核磁共振氢谱、摩尔电导率等对配合物结构进行了研究。结果表明两分子配体分别失去了酚羟基上的氢 ,通过 S、 N、 O与一分子 Cu2 + 配位成中性配合物 相似文献
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