An effective visible-light driven fumarate production from gaseous CO and pyruvate by the cationic zinc porphyrin-based photocatalytic system with dual biocatalysts.

Fumaric acid is a useful unsaturated dicarboxylic acid that serves as a precursor for the biodegradable plastics poly(butylene succinate) and poly(propylene fumarate). Currently, fumaric acid is mainly synthesised from petroleum resources such as benzene. It is therefore desirable to develop methods to produce fumaric acid from renewable resources such as those derived from biomass.

Visible-light driven 3-hydroxybutyrate synthesis from CO and acetone with the hybrid system of photocatalytic NADH regeneration and multi-biocatalysts.

Poly-3-hydroxybutyrate (PHB)-derived plastics are polymer materials with excellent biodegradability, being insoluble in water and relatively resistant to hydrolysis. There is a need for a method capable of synthesizing 3-hydroxybutyrate, a monomer of PHB, from a renewable material. In this work, visible-light driven 3-hydroxybutyrate from CO and acetone with the system consisting of triethanolamine, water-soluble zinc porphyrin, pentamethylcyclopentadienyl coordinated rhodium complex, NAD and a cell extract containing acetone carboxylase and 3-hydroxybutyrate dehydrogenase from SB1003 cultured in acetone-bicarbonate medium is established.

Visible-light-driven CO reduction to formate with a system of water-soluble zinc porphyrin and formate dehydrogenase in ionic liquid/aqueous media.

Visible-light-driven CO reduction to formate with a system consisting of water-soluble zinc tetraphenylporphyrin tetrasulfonate (ZnTPPS), formate dehydrogenase from (CbFDH) and methylviologen (MV) in the presence of triethanolamine (TEOA) as an electron donor in an ionic liquid, 1-ethyl-3-methylimidazolium dimethyl phosphate ([EMlm][MePO])/aqueous media was investigated. The catalytic activity of CbFDH for formate oxidation to CO and CO reduction to formate did not decrease significantly even in [EMlm][MePO]/aqueous media, compared with that in aqueous media. The visible-light-driven MV reduction by the photosensitization of ZnTPPS in [EMlm][MePO]/aqueous media proceeds more efficiently than in the aqueous media system.

Theoretical study on CO reduction catalyzed by formate dehydrogenase using the cation radical of a bipyridinium salt with an ionic substituent as a co-enzyme.

Formate dehydrogenase from Candida boidinii (CbFDH; EC.1.2.

How does methylviologen cation radical supply two electrons to the formate dehydrogenase in the catalytic reduction process of CO to formate?

Formate dehydrogenase from Candida boidinii (EC.1.2.

Visible-light driven hydrogen production using chlorophyll derivatives conjugated with a viologen moiety in the presence of platinum nanoparticles.

The utilization of the light-harvesting and electron-transferring function of chlorophylls (Chls) has received attention for visible-light driven hydrogen production. In this work, a series of Chl derivatives based on pyropheophorbide-a (Pyro-a) conjugated with a viologen moiety, including a Pyro-a methyl ester directly bonded with the viologen at the 3-position 1, its 31-methylene analog 2 and Pyro-a connected with the viologen in the 17-substituent 3, were synthesized from chemical modification of naturally occurring Chl-a and characterized in terms of their photochemical and photophysical properties. As the photoexcited singlet state of the Pyro-a moiety was strongly quenched by the viologen moiety in a molecule, the effective photoinduced intramolecular electron transfer from Pyro-a to the bonded viologen moiety occurred.

A Coincidental Discovery of a New Stable Variant (Hb Hachioji or HBB: c.187C>T) in a Patient with Chronic Hemolytic Anemia of Unexplained Origin.

We report a new hemoglobin (Hb) variant, Hb Hachioji (HBB: c.187C>T), which was detected in a 32-year-old male with hemolytic anemia. The proband had undergone splenectomy in his childhood after being diagnosed with hereditary spherocytosis (HS) with no clinical improvement.

The effect of the functional ionic group of the viologen derivative on visible-light driven CO reduction to formic acid with the system consisting of water-soluble zinc porphyrin and formate dehydrogenase.

The effect of the functional ionic group of 4,4'-bipyridinium salt derivatives (4,4'-BPs) as the electron carrier on the visible-light driven conversion of CO to formic acid with the system consisting of water-soluble zinc tetraphenylporphyrin tetrasulfonate (ZnTPPS) and formate dehydrogenase (FDH) in the presence of triethanolamine (TEOA) as an electron donor was investigated. 1,1'-Diaminoethyl- (DAV), 1-aminoethyl-1'-methyl- (AMV), 1-carboxymethyl-1'-methyl- (CMV) and 1,1'-dicarboxymethyl-4,4'-bipyridinium salt (DCV) were prepared as the 4,4'-BPs with the functional ionic group. Irradiation of a CO saturated buffer solution containing TEOA, ZnTPPS, 4,4'-BP and FDH with visible light irradiation resulted in the production of formic acid.

Development of a dye molecule-biocatalyst hybrid system with visible-light induced carbon-carbon bond formation from CO as a feedstock.

Recently, CO utilization technology, including artificial photosynthesis, has received much attention. In this field, CO is used as a feedstock for fuels, polymers and in other chemical processes. Of note are malic enzymes (MEs) which catalyze the reaction of malic acid to pyruvic acid and CO with the co-enzyme NADP, and catalyze the reverse reaction of pyruvic acid and CO to malic acid with the co-enzyme NADPH.

CO Photoreduction by Formate Dehydrogenase and a Ru-Complex in a Nanoporous Glass Reactor.

In this study, we demonstrated the conversion of CO to formic acid under ambient conditions in a photoreduction nanoporous reactor using a photosensitizer, methyl viologen (MV), and formate dehydrogenase (FDH). The overall efficiency of this reactor was 14 times higher than that of the equivalent solution. The accumulation rate of formic acid in the nanopores of 50 nm is 83 times faster than that in the equivalent solution.

Artificial leaf device for solar fuel production.

Solar fuels, such as hydrogen gas produced from water and methanol produced from carbon dioxide reduction by artificial photosynthesis, have received considerable attention. In natural leaves the photosynthetic proteins are well-organized in the thylakoid membrane. To develop an artificial leaf device for solar low-carbon fuel production from CO2, a chlorophyll derivative chlorin-e6 (Chl-e6; photosensitizer), 1-carboxylundecanoyl-1'-methyl-4,4'-bipyrizinium bromide, iodide (CH3V(CH2)9COOH; the electron carrier) and formate dehydrogenase (FDH) (the catalyst) immobilised onto a silica-gel-based thin layer chromatography plate (the Chl-V-FDH device) was investigated.

Immobilization and Photocurrent Activity of a Light-Harvesting Antenna Complex II, LHCII, Isolated from a Plant on Electrodes.

A light-harvesting (LH) antenna complex II, LHCII, isolated from spinach was immobilized onto an indium tin oxide (ITO) electrode with dot patterning of 3-aminopropyltriethoxysilane (APS) by utilizing electrostatic interactions between the cationic surface of the electrode and the anionic surface of stromal side of the LHCII polypeptide. Interestingly, the illumination of LHCII assembled onto the ITO electrode produced a photocurrent response that depends on the wavelength of the excitation light. Further, LHCII was immobilized onto a TiO nanostructured film to extend for the development of a dye-sensitized biosolar cell system.

Photoinduced biohydrogen production from biomass.

Photoinduced biohydrogen production systems, coupling saccharaides biomass such as sucrose, maltose, cellobiose, cellulose, or saccharides mixture hydrolysis by enzymes and glucose dehydrogenase (GDH), and hydrogen production with platinum colloid as a catalyst using the visible light-induced photosensitization of Mg chlorophyll-a (Mg Chl-a) from higher green plant or artificial chlorophyll analog, zinc porphyrin, are introduced.

Optical CO(2) sensor of the combination of colorimetric change of alpha-naphtholphthalein in poly(isobutyl methacrylate) and fluorescent porphyrin in polystyrene.

An optical CO(2) sensor based on the overlay of the CO(2) induced absorbance change of pH indicator dye alpha-naphtholphthalein in poly(isobutyl methacrylate) (polyIBM) layer with the fluorescence of tetraphenylporphyrin (TPP) in polystyrene layer is developed. The observed luminescence intensity from TPP at 655nm increased with increasing the CO(2) concentration. The ratio I(100)/I(0) value of the sensing film consisting of alpha-naphtholphthalein in polyIBM and TPP in polystyrene layer, where I(0) and I(100) represent the detected luminescence intensities from a layer exposed to argon and CO(2) saturated conditions, respectively, that the sensitivity of the sensor, is estimated to be 192.

Optimising oxygen-sensitivity of optical sensor using pyrene carboxylic acid by myristic acid co-chemisorption onto anodic oxidized aluminium plate.

Optical oxygen-sensitivity using pyrene carboxylic acid with long alkyl chain (1-pyrenedecanoic acid and 1-pyrenedodecanoic acid) and myristic acid co-chemisorption layer was controlled by varying the molar ratio of myristic acid to pyrene carboxylic acid. The ratio I(0)/I(100), where I(0) and I(100) represent the detected fluorescence intensities from a substrate exposed to 100% argon and 100% oxygen, respectively, is used as an indicator of the sensitivity of the sensing film. At a composition ratio of 1 pyrene carboxylic acid to 10 myristic acids, the I(0)/I(100) attained its maximum value and then the ratio decreased with increase in the molar ratio of myristic acid to pyrene carboxylic acid.

Optical oxygen-sensing properties of porphyrin derivatives anchored on ordered porous aluminium oxide plates.

An optical oxygen-sensing activity of anchored porphyrin derivatives on ordered porous aluminium oxide plates was studied in relevance to development of new oxygen-sensing systems. Porphyrin derivatives, 5,10,15,20-tetrakis(4-carboxylundecane-1-oxy)porphyrin, 5-[4-(11-carboxylundecane-1-oxy)-10,15,20-triphenyl]porphyrin, 5-(4-carboxylphenyl)-10,15,20-triphenylporphyrin, and their platinum complexes, 5,10,15,20-tetrakis(4-carboxylundecane-1-oxy)porphyrinatoplatinum(II), 5-[4-(11-carboxylundecane-1-oxy)-10,15,20-triphenyl]porphyrinatoplatinum(II), 5-(4-carboxylphenyl)-10,15,20-triphenylporphyrinatoplatinum(II), were synthesized and anchored by an equilibrium adsorption method on aluminium oxide plates, which were prepared by an anodic oxidation. The excitation spectra of the porphyrin-anchored layers showed a broadened and blue-shifted Soret band compared with the corresponding porphyrins in DMSO.

Photovoltaic conversion using Zn chlorophyll derivative assembled in hydrophobic domain onto nanocrystalline TiO2 electrode.

Photovoltaic conversion using zinc chlorin-e6 (ZnChl-e6), which is zinc chlorophyll-a derivative, and fatty acid (myristic acid or cholic acid) co-adsorbed nanocrystalline TiO2 layer onto ITO glass (OTE) electrode is developed. The maximum peaks of photocurrent action spectrum of the ZnChl-e6 adsorbed TiO2 layer onto OTE (ZnChl-e6/TiO2) are 400, 660 and 800 nm, respectively. Especially the IPCE value at 800 nm (7.

Photochemical and photophysical properties of carotenoid immobilized on a surfactant micellar medium including chlorophyll as an artificial photosynthesis system.

To develop an artificial photosynthesis model, the anionic water-soluble carotenoid dye crocetin was electrostatically immobilized onto the surface of cationic surfactant cetyltrimethylammonium bromide (CTAB) micellar medium including Mg chlorophyll- and (MgChl- and ) (Cro/MgChl), and its photophysical properties were studied using UV-vis absorption and fluorescence spectroscopy. The fluorescence of MgChl- and was observed, with the excitation wavelength attributed to the absorption band of crocetin, indicating that photo-induced energy transfer from the photoexcited state of crocetin to MgChl- and occurs. The photostability of MgChl- and in Cro/MgChl was investigated under continuous irradiation.

Photoreduction behavior of cytochrome c by zinc porphyrin in lipid media.

To elucidate the role of cardiolipin (CL) on redox behavior of cytochrome c (cyt c (III)), the photoreduction of cyt c using the photosensitization of zinc tetraphenylporphyrin in presence of triethanolamine (TEOA) as a sacrificial electron-donating reagent in various lipid media were studied. The initial rate of cyt c (III) photoreduction in various lipid, CL, l-alpha-phosphatidic acid (PA), dimethyldipalmitoylammonium bromide (DMPA) and Triton X-100 media were 1.0, 0.

Light-harvesting properties of zinc complex of chlorophyll-a from spirulina in surfactant micellar media.

Zn chlorophyll-a was prepared from Mg chlorophyll-a from spirulina and the optical properties of the ground state and the photoexited state of Zn chlorophyll-a in aqueous surfactant micellar media were studied using UV-vis absorption, fluorescence emission spectra, electrochemical and fluorescence lifetime measurements. In comparison of the UV-vis absorption and fluorescence emission spectra of Zn chlorophyll-a and Mg chlorophyll-a, the blue-shift in the absorption bands and emission peak of Zn chlorophyll-a was observed. The energies of the first excited singlet state of Zn chlorophyll-a was 1.

Near-IR light-sensitized voltaic conversion system using nanocrystalline TiO2 film by Zn chlorophyll derivative aggregate.

A Zn chlorophyll-a derivative, Zn chlorin-e6 (ZnChl-e6), adsorbed onto a nanocrystalline TiO2 film (ZnChl-e6/TiO2) electrode was prepared, and the photovoltaic properties of the ZnChl-e6/TiO2 electrode were studied. The absorption peaks of ZnChl-e6/TiO2 observed at 420, 654, and 795 nm were attributed to the ZnChl-e6 molecules aggregating onto TiO2 film. The fluorescence attributed to the ZnChl-e6 monomer and aggregate was observed at 710 and 820 nm, respectively, and the fluorescence in both cases was quenched by TiO2 particles.

Lactic acid production with lactate dehydrogenase using the visible light sensitization of zinc porphyrin.

Lactic acid production with L-lactate dehydrogenase from Pig heart (LDH) and reduced methyl viologen produced by the visible light photosensitization of zinc tetrakis(4-methylpyridyl)porphyrin (ZnTMPyP) was investigated. When the sample solution containing triethanolamine as an electron-donating reagent, ZnTMPyP, methyl viologen as an electron carrier, pyruvic acid and LDH in potassium phosphate buffer (pH 7) was irradiated, lactic acid production was observed. After 240 min irradiation, the amount of lactic acid production and the yield of pyruvic acid to lactic acid were estimated to be 0.

Bio-photovoltaic conversion device using chlorine-e6 derived from chlorophyll from Spirulina adsorbed on a nanocrystalline TiO2 film electrode.

A bio-photovoltaic conversion device based on dye-sensitised solar cell (DSSC) using the visible light sensitisation of chlorine-e6 (Chl-e6) derived from chlorophyll from Spirulina adsorbed on a nanocrystalline TiO2 film was developed. Form fluorescence spectrum of Chl-e6 adsorbed on a nanocrystalline TiO2 film, the emission of Chl-e6 was effectively quenched by TiO2 nanocrystalline indicating that the effective electron injection from the excited singlet state of Chl-e6 into the conduction band of TiO2 particles occurred. The short-circuit photocurrent density (Isc).

Optical sensor for carbon dioxide combining colorimetric change of a pH indicator and a reference luminescent dye.

A new optical CO(2) sensor based on the luminescence intensity change of the europium(III) complex tris(thenoyltrifluoroacetonato) europium(III) dihydrate ([Eu(tta)(3)]) caused by the absorption change of various pH indicators-thymol blue, phenol red, or cresol red-with CO(2) was developed and its CO(2) sensing properties were investigated. For all the CO(2) sensors using pH indicators the observed luminescence intensity from [Eu(tta)(3)] at 613 nm increased with increasing CO(2) concentration. The linear calibration method based on the plot of (I(100)-I(0))/(I-I(0)) versus the inverse of CO(2) concentration was suggested, where I(0) and I(100) were luminescence intensities at 613 nm of the CO(2) sensor film in 100% nitrogen and 100% gaseous CO(2).