2002 Fiscal Year Final Research Report Summary
Analytical study of catechins in lipid bilayers
| Project/Area Number |
13660131
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
食品科学・栄養科学
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| Research Institution | University of Shizuoka |
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Principal Investigator |
NAKAYAMA Tsutomu University of Shizuoka, School of Food and Nutritional Sciences, Professor, 食品栄養科学部, 教授 (50150199)
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| Co-Investigator(Kenkyū-buntansha) |
SAITO Hazime Himeji Institute of Technology, Department of Life Science, Professor, 理学部, 教授 (30100150)
KUMAZAWA Shigenori University of Shizuoka, School of Food and Nutritional Sciences, Assistant Professor, 食品栄養科学部, 助手 (10295561)
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| Project Period (FY) |
2001 – 2002
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| Keywords | lipid bilayer / catechins / EGCg / D-NMR / solid state NMR / analytical study / liposome / antibacterial activity |
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| Research Abstract |
(1) Interaction of tea catechins with lipid bilayers has been investigated with liposome systems. As structural factors of catechins, the number of hydroxyl groups on the B-ring and the presence of the galloyl moiety, and the stereochemical structure of the C-ring governed the affinity for the lipid bilayers. As external factors, the salt concentration in an aqueous medium, the electric charge of the membrane, and the presence of other catechins also governed the affinity for lipid bilayers.
(2) The gallocatechins such as EGC and EGCg were oxidized by superoxide, accompanied by the formation of hydrogen peroxide, and their cytotoxic effects were ascribed to the hydrogen peroxide formation.
(3) The interaction of EGCg with the model membrane of dimyristoylphosphatidylcholine was studied by solid-state ^<31>P-and ^2H-NMR. These NMR observations provide the first direct experimental evidence that an EGCg molecule is incorporated into the lipid bilayers.
(4) The antibacterial activity of (+)-catechin derivatives with various alkyl chain lengths was evaluated with Gram-positive bacteria. The antibacterial activity of the compounds with the alkyl chain of 4 to 6 carbons was very high. Investigation of the interaction of these derivatives with lipid bilayers revealed that the reinforcement of the antibacterial activity by the derivatization arises form the damage to bacterial membranes.
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Research Products
(6 results)
