Keiji Hashimoto

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Carotenoids were investigated in three species of corbicula clams, Corbicula japonica, Corbicula sandai, and Corbicula sp. (Chinese freshwater corbicula clam). Forty-three carotenoids were isolated. Among them, 7,8-didehydro-beta-cryptoxanthin (12), peridininol 5,8-furanoxide (38), pyrrhoxanthin 5,8-furanoxide (40), and pyrrhoxanthinol 5,8-furanoxide (43)(More)
Fucoxanthin and fucoxanthinol fatty acid esters in the clam, Mactra chinensis, were characterized on the basis of 1H NMR and FAB-MS spectra. 1H NMR revealed that the hydroxy group at C-3 in fucoxanthin and fucoxanthinol was acylated. 3'-O-Acylated compounds such as fucoxanthinol 3'-ester or fucoxanthinol 3,3'-diester were not found in the clam. The fatty(More)
Colloidal gold (Au) nanoparticles were prepared and successfully loaded on titanium(IV) oxide (TiO(2)) without change in the original particle size using a method of colloid photodeposition operated in the presence of a hole scavenger (CPH). The prepared Au nanoparticles supported on TiO(2) showed strong photoabsorption at around 550 nm due to surface(More)
Au/CeO(2) samples with various Au contents were prepared by the multistep (MS) photodeposition method. Their properties including Au particle size, particle dispersion, and photoabsorption were investigated and compared with properties of samples prepared by using the single-step (SS) photodeposition method. The MS- and SS-Au/CeO(2) samples were used for(More)
A functionalized plasmonic Au/TiO2 photocatalyst with an Ag co-catalyst was successfully prepared by the combination of two types of photodeposition methods, and it quantitatively converted nitrobenzene and 2-propanol to aniline and acetone under irradiation of visible light.
(2,3-Epoxypropyl)benzene was chemoselectively reduced to allylbenzene along with formation of ketones in alcoholic suspensions of a silver-loaded titanium(iv) oxide photocatalyst at room temperature under atmospheric pressure without the use of reducing gases, and various epoxides were also reduced to the corresponding alkenes.
Nitrite (NO(2)(-)) was photocatalytically reduced to dinitrogen (N(2)) in an aqueous suspension of two kinds of titanium(iv) oxide particles loaded with palladium and silver (Pd-TiO(2) and Ag-TiO(2)) at pH 8 under irradiation of UV light in the presence of sodium oxalate as a hole scavenger. The two metal-loaded TiO(2) photocatalysts had different roles in(More)
Six new carotenoids, named corbiculaxanthin (1), corbiculaxanthin 3'-acetate (2), 6-epiheteroxanthin (3), 7',8'-didehydrodeepoxyneoxanthin (4), cyclopyrrhoxanthin (5), and hydratoperidinin (6), were isolated from the corbicula clam (Shijimi in Japanese), Corbicula japonica. Their structures were determined by chemical and spectral data.
Photocatalytic H2 and O2 formations under visible light irradiation (λ > 400 nm) are demonstrated using Pt-Au nanopaticles for the reduction site and WO3 for the oxidation site in solid-state Pt/Au/WO3.