| Project/Area Number |
15580110
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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 |
Food science
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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) |
KUMAZAWA Shigenori University of Shizuoka, School of Food and Nutritional Sciences, Associate Professor, 食品栄養科学部, 助教授 (10295561)
NAITO Akira Yokohama National University, Graduate School of Engineering, Professor, 大学院・工学研究院, 教授 (80172245)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2004: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2003: ¥2,900,000 (Direct Cost: ¥2,900,000)
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| Keywords | lipid bilayer / polyphenol / EGCg / solid-state NMR / liposome / isoflavone / catechin / phenolic acid / ポリフェノール / 茶カテキン類 / リポソーム / 固体NMR / 脂質二重層 / 水晶発振子マイクロバランス / QCM / テアフラビン / カテキン類 / イソフラボン / 抗菌性 / (+)-catechin |
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| Research Abstract |
(1) The amount of incorporated into liposomes was measured to determine lipophilicity of isoflavonoids. The presence of a hydroxyl group at 5-position of the A-ring and a methoxyl group at 4'-position of the B-ring in the isoflavonoid structure increased the amount incorporated. The cytotoxicity of isoflavonoids was investigated by a colony-formation assay with V79 cells. The structure-activity relationship of the cytotoxic activity reflected the amount incorporated.
(2) The antibacterial activity of (+)-catechin derivatives increased with elongation of the alkyl chain length. The derivatives with a chain of three carbons or more showed strong affinity for the liposome membrane. The derivatives with chains longer than five carbons destroyed the membrane. These results implied that the lipophilicity and disrupting ability of the (+)-catechin derivatives to the liposome membrane participate in their antibacterial activity.
(3) Antioxidant effects of the phenolic acids, caffeic acids, p-coumaric acid, and ferulic acid, were investigated by monitoring O_2 consumption in the linoleic acid micelles in the presence of H_2O_2 and metmyoglobin. The main antioxidant effects of the phenolic acids was ascribed to reduction of ferrylmyoglobin at pH 7.4 and inhibition of the chain reaction occurring inside of the micelles in the second phase at pH 3.4.
(4) The interaction of a tea catechin, epigallocatechin gallate (EGCg), with the model membrane of dimyristoylphosphatidylcholine (DMPC) was studied by solid-state ^<31>P and ^2H NMR. The ^<31>P chemical shift anisotropy of the DMPC phosphate group decreased on addition of EGCg. The ^2H NMR spectrum of [4-^2H]EGCg in the DMPC liposomes gave deuterium nuclei with much smaller quadrupole splittings than those in the solid phase. These observations provide direct experimental evidence that the EGCg molecule interacts with the lipid bilayers.
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