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Shii T.,Nagasaki University | Tanaka T.,Nagasaki University | Watarumi S.,Nagasaki University | Matsuo Y.,Nagasaki University | And 5 more authors.
Journal of Agricultural and Food Chemistry | Year: 2011

Phenolic constituents of a new functional fermented tea produced by tea-rolling processing of a mixture (9:1) of tea leaves and loquat leaves were examined in detail. The similarity of the phenolic composition to that of black tea was indicated by high-performance liquid chromatography comparison with other tea products. Twenty-five compounds, including three new catechin oxidation products, were isolated, and the structures of the new compounds were determined to be (2R)-2-hydroxy-3-(2,4,6-trihydroxyphenyl)-1-(3,4,5- trihydroxyphenyl)-1-propanone 2-O-gallate, dehydrotheasinensin H, and acetonyl theacitrin A by spectroscopic methods. In addition, theacitrinin A and theasinensin H were obtained for the first time from commercial tea products. Isolation of these new and known compounds confirms that reactions previously demonstrated by in vitro model experiments actually occur when fresh tea leaves are mechanically distorted and bruised during the production process. © 2011 American Chemical Society.

Suga Y.,Nagasaki Agricultural and Forestry Technical Development Center | Suga Y.,Kyushu University | Horita M.,Japan National Institute for Agro - Environmental Sciences | Umekita M.,Kyushu University | And 2 more authors.
Journal of General Plant Pathology | Year: 2013

Ralstonia solanacearum (Rs) strains in phylotypes I and IV isolated from potato in Japan were investigated for pathogenicity on potato, tomato, eggplant, Solanumintegrifolium, tobacco, groundnut, and pumpkin. The strains were divided into 17 types based on differences in their pathogenicity on the tested plants. Particularly, the pathogenicity of most phylotype I strains on eggplant was distinctly different from that of the phylotype IV strains. When nine potato varieties (included two breeding lines) were inoculated with several Rs strains, phylotype IV strains were highly virulent on the breeding lines that are regarded as resistant to phylotype I strains. © 2013 The Phytopathological Society of Japan and Springer Japan.

Maeda H.,Nagasaki University | Maeda H.,Nagasaki Agricultural and Forestry Technical Development Center | Kakoki N.,Nagasaki University | Ayabe M.,Nagasaki University | And 5 more authors.
Phytochemistry | Year: 2011

ent-Eudesmane sesquiterpenoids, 8,11-dihydroxy-2,4-cycloeudesmane, 11-hydroxy-2,4-cycloeudesman-8-one and 2,4-cyclo-7(11)-eudesmen-8-one, were isolated from the wood of Platycarya strobilacea, which has been used as an aromatic tree since at least the 18th century. On charring the wood, 2,4-cyclo-7(11)-eudesmen-8-one was detected in the smoke. In the charred wood, the concentrations of ellagitannins, such as galloyl pedunculagin, dramatically decreased, whereas concentrations of pentagalloyl glucose, and other gallotannins were relatively stable. In addition, two other compounds, the 6′-O-m- and p-digalloyl oak lactone precursor and the 3-O-methylellagic acid 4′-O-(4″-O-galloyl)-xylopyranoside, were isolated from the charred wood along with m- and p-digallic acid. © 2011 Elsevier Ltd. All rights reserved.

Cao R.,Kyushu University | Kobayashi Y.,Kyushu University | Nonaka A.,Kyushu University | Miyata Y.,Nagasaki Agricultural and Forestry Technical Development Center | And 3 more authors.
Pharmaceutical Research | Year: 2015

Purpose: The use of hesperidin in the pharmaceutical field is limited by its aqueous insolubility. The effects of natural compounds in tea on the solubility of hesperidin were evaluated and the underlying mechanism was investigated by nuclear-magnetic resonance (NMR) and quantum mechanical calculations. Methods: The solubility of hesperidin was measured by liquid chromatography time-of-flight mass spectrometry; the structure of the hesperidin/theasinensin A complex was characterized by 1H-NMR, diffusion-ordered NMR spectroscopy, and rotating frame NOE spectroscopy, as well as theoretically by quantum mechanical calculations. Results: Among the natural compounds in tea, theasinensin A was the most effective in improving hesperidin solubility. The complexation of hesperidin with theasinensin A led to changes in the chemical shift of protons in hesperidin (Δδ: 0.01-0.27 ppm) and diffusion coefficient (ΔD: 0.66-1.32∈×∈10-10 m2/s) of hesperidin. ROE correlation signals between hesperidin and theasinensin A and quantum mechanical calculations revealed that two hesperidin molecules formed a stable complex with theasinensin A (2:1 complex) with a ΔG energy of -23.5 kJ/mol. Conclusions: This is the first study that provides insight into the enhanced solubility of hesperidin through interactions with theasinensin A via a 2:1 complex formation between hesperidin and theasinensin A. © 2015 Springer Science+Business Media New York.

Omar M.,Nagasaki University | Omar M.,Al - Azhar University of Egypt | Matsuo Y.,Nagasaki University | Maeda H.,Nagasaki Agricultural and Forestry Technical Development Center | And 2 more authors.
Phytochemistry Letters | Year: 2013

Two novel glycosides, 4,5-dimethoxy-3-hydroxyphenol 1-O-β-(6′-O- galloyl)-glucopyranoside (1) and (+)-2α-O-galloyl lyoniresinol 3α-O-β-D-xylopyranoside (2), as well as a novel ellagitannin named epiquisqualin B (3), were isolated from sapwood of Quercus mongolica var. crispula along with 19 known phenolic compounds. The structures of the novel compounds were elucidated on the basis of chemical and spectroscopic investigation. Compound 2 is the first example of a lignan galloyl ester, and 3 is the oxidation product of vescalagin, which is the major ellagitannin of this plant. © 2013 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.

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