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Asparagus (Asparagus officinalis L.) accumulates inulin- and inulin neoseries-type fructans. Fructose released by the hydrolysis of fructans is an energy source for emerging asparagus spears. Plant fructans are hydrolyzed by fructan exohydrolases (FEHs), whose presence in asparagus has not yet been fully characterized. Here, we describe for the first time the purification and characterization of an FEH from asparagus, and the functional analysis of its gene. The purified enzyme was predicted to exist as a dimer (approximately 130 kDa) consisting of two polypeptides with a molecular mass of approximately 68 kDa. N-terminal sequences of the purified enzyme were matched with the amino acid sequences of aoeh4a and aoeh4b cDNAs isolated from asparagus (cv. Gijnlim and Taihouwase). Native enzymes obtained from asparagus roots and recombinant enzymes produced by Pichia pastoris showed fructan 1-exohydrolase (1-FEH) activity via the hydrolysis of inulin-type fructan. Unlike other 1-FEHs, these enzymes showed minimal hydrolysis of 1-kestose but efficiently hydrolyzed neokestose. Therefore, the enzyme was termed 6G&1-FEH. Gene expression studies in asparagus roots showed that aoeh4 increased during root storage at 2 °C and spear harvesting. These findings suggest that 6G&1-FEH may be involved in fructan hydrolysis in asparagus roots to provide an energy source for emerging asparagus spears.

The synthesis of the saccharide β-D-fructopyranosyl-(2→6)-D-glucopyranose, which was isolated from Super Ohtaka®, has recently been reported. During the synthesis of this saccharide, the formation of two novel saccharides from D-glucose and D-fructose was observed. The present study aimed to confirm the structures of the two disaccharides synthesized from D-glucose and D-fructose by thermal treatment. Furthermore, various properties of the saccharides were investigated. Both saccharides were isolated from the reaction mixture by carbon-Celite column chromatography and an HPLC system and were determined to be novel sucrose-isomers, β-D-fructopyranosyl-(2↔1)-β-D-glucopyranoside (1) and β-D-fructofuranosyl-(2↔1)-β-D-glucopyranoside (2), by MALDI-TOF MS and NMR analyses. Both saccharides showed low digestibility in vitro, and the sweetness of saccharide 2 was 0.45 times that of sucrose.

A fermented beverage of plant extracts (Super Ohtaka®) was prepared from about 50 kinds of fruits and vegetables. This natural fermentation was performed by yeast (Zygosaccharomyces spp. and Pichia spp.) and lactic acid bacteria (Leuconostoc spp.) and resulted in the production of a novel fructopyranose-containing saccharide, which was subsequently isolated using carbon-Celite column chromatography and preparative-HPLC. The structure of the saccharide was determined using MALDI-TOF MS and NMR, and the saccharide was identified as β-D-fructopyranosyl-(2→6)-β-D-fructofuranosyl-(2↔1)-α-D-glucopyranoside. This is the first description of this novel saccharide and its isolation from a natural source.

Aluminum oxide (AlOx) thin films were grown using aluminum acetylacetonate [Al(acac)3] as a source material with methanol and water as the solvent by mist chemical vapor deposition, while also exposing some films to water or methanol mists after fabrication. The incorporation of –OH groups into the AlOx network that is fabricated from Al(acac)3 and using solely methanol as a solvent generates both malformed Al(OH) network and nonuniformity. However, the addition of a small amount of water in the solvent during film growth decreases the deposition rate due to the hydrogen bond in water molecules but markedly removes –OH groups from the growth surface of the AlOx network and improves the surface uniformity. The AlOx thin films grown with a methanol:water ratio of 7:3 at 400 °C exhibit a recombination velocity of 16 cm/s, a breakdown field of 6.9 MV/cm, and an interface trap density of 4.2 × 1010 cm−2 eV−1, which are compatible with the AlOx grown by the other vacuum-based methods.

By using a technique of thermoreflectance that can precisely measure the thermal conductivity of thin films, we found that the thermal conductivity of ${\mathrm{SrVO}}_{3}\text{\ensuremath{-}}{\mathrm{SrTiO}}_{3}$ multilayer thin films normal to the surface was substantially reduced by decreasing the thickness of each layer. This indicates that a large intrinsic thermal resistance exists at the interface between ${\mathrm{SrVO}}_{3}$ and ${\mathrm{SrTiO}}_{3}$ in spite of the similar phononic properties for these two compounds.

We prepare transparent, selfassembled polygonal silver nanowire (AgNW) mesh by bubble template and use as top electrode for a poly (3,4ethylenedioxythiophene):poly(stylenesulfonate) (PEDOT:PSS)/n-Si hybrid solar cell. Devices were fabricated by pressing the self-assembled AgNW and ITO electrodes onto the surface of the PEDOT:PSS and device performances were compared. In identical transmittances of ITO and self-assembled AgNW (i.e., 87% transmittance at wavelength of 550 nm), the self-assembled AgNW mesh electrodes shows lower sheet resistance (8 Ω/square) with enhanced transparency in the ultraviolet and infrared regions. As a result, a device performance with an efficiency of 9.60% was obtained with the self-assembled electrode compared to 9.07% efficiency from the indium–tin oxide (ITO) electrode under 100 mW/cm2 of AM 1.5 illumination. This study suggests the potential application of a self-assembled AgNW electrode as the transparent conducting electrode for future optoelectronic devices.

We prepare transparent, self-assembled polygonal silver nanowire (AgNW) mesh by bubble template and transferred as top electrode in poly(3,4-ethylenedioxythiophene):poly(stylenesulfonate) (PEDOT:PSS)/n-silicon hybrid solar cell, which shows power conversion efficiency of 10.62% under 100 mW/cm 2 of AM 1.5G illuminations. The self-assembled AgNW mesh electrode exhibited a low sheet resistance (50 Ω/square) with high transmittance (87%) at a wavelength of 550 nm. In self-assembled AgNW mesh, AgNWs are well packed making continuous path for charge collection and transportation. Nevertheless, studies have also been carried out to transfer AgNWs from donor (glass or plastic) to receiver substrates (thermal release tape) and an expected reason for the transfer of AgNWs from thermal release tape to the top of PEDOT:PSS has also been proposed.

Fresh edible burdock roots were stored in soil of 1 m depth underground from November to May. Three fructooligosaccharide derivatives without a terminal glucose residue, designated saccharides 1, 2 and 3, were generated in the stored burdock roots. They were purified from the sugar extract using carbon-Celite column chromatography. Saccharides 1, 2 and 3 have R-sucrose values (retention time of sucrose = 1) of 1.55, 2.15 and 2.73 by HPAEC, reducing terminal, molar ratios (reducing sugar to D-fructose) of 0.50, 0.33 and 0.25 and degrees of polymerization of 2, 3 and 4 by TOF-MS, respectively. Analyses by GLC and NMR confirmed the three different following structures: first was inulobiose [β-D-fructofuranosyl-(2→1)-β-D-fructopyranose], and the two others were inulotriose [β-D-fructofuranosyl-(2→1)-β-D-fructofuranosyl-(2→1)-β-D-fructopyranose] and inulotetraose [β-D-fructofuranosyl-(2→1)-β-D-fructofuranosyl-(2→1)-β-D-fructopyranose]. The NMR spectra showed that 70 to 80 % of the terminal fructose residue of the three saccharides is pyranosyl form, while 20 to 30 % is furanosyl form. The ^C_- and ^1H-signals were also assigned by 2D-NMR including COSY, HSQC, HSQC-TOCSY and HMBC. These saccharides could be synthesized by purified burdock fructan:fructan 1-frustosyltransferase from 1-kestose to free D-fructopyranose giving inulobiose and sucrose, while elongation of fructoranosyl units occurred at this trasferred fructofuranosyl residue to produce inuloolisaccharides having one, two and more additional units of fructofuranose. 新鮮ごぼう根を地下1mの土中で11月から翌年の5月まで6カ月間貯蔵した。この貯蔵ごぼうに末端グルコース残基を有しないフルクトオリゴ糖が新しく生成された。このごぼうから抽出した糖液について電気化学検出器付陰イオン交換高速液体クロマトグラフィー(HPAEC)分析を行ったところ，糖1は1- kestose (3a)のあとに溶出され，糖2，3はnystose (4a), fructosylnystose (5a)のあとにそれぞれ溶出された。この糖抽出液について活性炭-セライトカラムクロマトグラフィーを行うことにより糖1，2，3を単離した。糖 1，2，3はHPAECによる相対保持時間(sucrose = 1)，1.55，2.15，2.73を有し，還元末端をそれぞれもっていた。また，糖1，2，3のフルクトースに対する還元糖の比は 0.50，0.33，0.25であることとTOF-MS分析の結果から糖1，2，3の重合度は2，3，4であることがわかった。これらの結果と各糖の NMR分析，糖メチル誘導体のGLC分析結果から，糖1，2，3はそれぞれβ-D-fructofuranosyl-(2→1)-β-D-fructopyranose (inulobiose)，β-D-fructofuranosyl-(2→1)-β-D-fructofuranosyl-(2→1)-β-D-fructopyranose (inulotriose)，β-D-fructofuranosyl-(2→1)-β-D-fructofuranosyl-(2→1)-β-D-fructofuranosyl-(2→1)-β-D-fructo-pyranose (inulotetraose)と同定された。13C-NMR分析により各糖の還元末端フルクトース残基の70-80％がピラノース構造をとることがわかった。それぞれの糖の13C-，1H- シグナルの完全帰属も初めて行った。さらに上述のごぼう貯蔵中に生成されたinulobiose，inulotriose，inulotetraoseと同様の糖が，ごぼうから精製したfructan fructan 1-fructosyltransferase (1-FFT)のフルクトシル転移作用により1-kestoseとD-フルクトピラノースから合成されることを初めて見出した。

A dinuclear complex bridged by a substituent-free gallium atom, Cp∗(dmpe)Fe–Ga–Fe(CO)4 (1b: Cp∗ = η-C5Me5, dmpe = Me2PCH2CH2PMe2), was synthesized by the reaction of Cp∗Fe(dmpe)GaCl2 with K2[Fe(CO)4]. Crystal structure analysis of complex 1b showed that the geometry around the gallium atom is essentially linear and the two Fe–Ga bonds are significantly shorter than those of usual single bonds, indicating the multiple bonding character of the Fe–Ga bonds. Comparison of the structure and IR data of 1b and those of Cp∗(dppe)Fe–Ga–Fe(CO)4 (1a: dppe = Ph2PCH2CH2PPh2) revealed that the Fe–Ga bond is sensitive to the electronic character of the metal fragment. The Fe–Ga bond is shortened upon introducing a more π-basic metal fragment.

Molecular orientations of pentacene ultrathin films grown on SiO2 substrates were studied without the influence of the atmosphere by vacuum atomic force microscopy (V-AFM) and near edge X-ray absorption fine structure (NEXAFS). The experimental processes from deposition of pentacene to characterization of films were performed under vacuum condition without exposure to the atmosphere. V-AFM and NEXAFS measurements showed that pentacene molecules tend to grow on SiO2 surface with their molecular long axes perpendicular to the substrate surfaces (standing-mode) irrespective of preparation procedure of SiO2 substrate. (c) 2006 Elsevier B.V. All rights reserved., http://www.sciencedirect.com/science/journal/00396028

Recently, we have investigated enzymic production of non-digestible oligosaccharides which have several functional activities as “tertiary functional ingredients” of foods. Fructo-oligosaccharides synthesized from sucrose by Eurotium repense fructosyltransferase had the effect of no elevation of blood glucose or insulin concentrations in rats. Fructosylxyloside formed from sucrose and xylose with fructosyltransferase action of Scopulariopsis brevicaulis cells suppressed serum glucose and insulin responses and / or promoted the absorption of calcium and magnesium ions in rats administered with sucrose. On the other hand, we studied purification and characterization of several fructosyltransferases; sucrose: sucrose 1-fructosyltransferase (1-SST), fructan: fructan 1-fructosyltransferase (1-FFT) and a new enzyme, fructan: fructan 6G-fructosyltransferase (6G-FFT) from asparagus roots. Previously, we reported that the asparagus 1-FFT synthesized new functional oligosaccharides elongated with one or two additional fructose units by fructosyltransfer from 1-kestose to 4G-β-D-galactosylsucrose and the saccharides selectively stimulated growth for Bifidobacteria. In this study, we have tried the isolation and expression of cDNAs encoding 6G-FFT, 1-FFT and 1-SST from asparagus for industrial use. The cDNAs encoding 6G-FFT, 1-FFT and 1-SST were isolated from a cDNA library of asparagus leaves or roots. The isolated cDNAs were named AoFT 1, AoFT 2 and AoFT 3, respectively. The deduced amino acid sequences of these cDNAs showed a high homology with those of plant fructosyltransferases. Expression of these cDNAs was done using Pichia pastoris. The recombinant protein from Pichia transformed with AoFT 1 produced 1F,6G-di-β-D-fructofuranosylsucrose, neokestose and sucrose from 1-kestose, while the transformant with an empty vector produced no saccharides. These results show that 6G-FFT is expressed in P. pastoris. In the same way, recombinant protein from Pichia transformed with AoFT 2 produced nystose from 1-kestose and AoFT 3 recombinant protein produced 1-kestose from sucrose. These results also show that 1-FFT and 1-SST are expressed in P. pastoris. Three recombinant proteins had enzymatic properties similar to those of 6G-FFT, 1-FFT and 1-SST from asparagus roots, respectively.

The anionic ruthenium and iron complexes Li[(η5-C5Me5)M(CO)2] (M=Ru (1-Ru), Fe (1-Fe)) were generated by deprotonation of the transition metal hydride (η5-C5Me5)M(CO)2H with n-BuLi in tetrahydrofuran (THF). The reaction proceeded at −45 °C immediately. Reactions of 1 with various electrophiles (Me3SiCl, pTol2HSiCl, Me2SiCl2, MeSiCl3, SiCl4, Me3SiSiMe2Cl, and Ph2GeCl2) afforded the corresponding nucleophilic substitution products (η5-C5Me5)M(CO)2ER3 (E=Si, Ge) via salt-elimination.

Nano-scale oxide patterns were fabricated on a bilayer-GaSe terminated Si(1 1 1) surface using an atomic force microscope (AFM) in air. The Si(1 1 1) surface regularly terminated by bilayer-GaSe is very stable in air, although it can be oxidized through the electrochemical reaction when positive sample bias voltage is applied between the surface and a conductive cantilever tip of AFM. It has been revealed that higher sample bias voltage, slower tip velocity and/or higher ambient humidity produce wider and/or thicker oxide protrusions. Then, nano-scale oxide patterns as narrow as 50 nm have been successfully drawn on the terminated surface by adjusting these experimental conditions. These oxide lines can be etched away by dipping the sample into aqueous HF solution, and nano-scale grooves can be fabricated on the bilayer-GaSe terminated Si(1 1 1) surface. (C) 2002 Elsevier Science B.V. All rights reserved.

29Si NMR coupling constants in a disilanyliron complex CpFe(CO)2SiMe2SiMe(OtBu)2 (1: CP = η5C5H5), a bis(silylene)iron complex Cp(OC)Fe{SiMe2 ⋯ O(tBu) ⋯ SiMeOtBu)} (2), and a cis-bis(silyl)iron complex (OC)4Fe{SiMe2CH2CH2SiMePh} (3) were measured by the INEPT-INADE-QUATE technique. The coupling constant for 2 (28.6 Hz) is much smaller than that for 1 (128 Hz) with a direct Si-Si bond, but larger than that for 3 (2.7 Hz) where there is no direct Si-Si bond. Model calculations using the extended Huckel method indicate that there is no direct bond between the two silicon atoms in the bis(silylene)iron complex Cp(OC)Fe{SiH2 ⋯ O(H) ⋯ SiH2}. This means that the coupling in 2 can be described as the sum of the two geminal couplings, 2J(SiFeSi) and 2J(SiOSi).

* Fructan:fructan 6G-fructosyltransferase (6G-FFT) catalyses a transfructosylation from fructooligosaccharides to C6 of the glucose residue of sucrose or fructooligosacchrides. In asparagus (Asparagus officinalis), 6G-FFT is important for the synthesis of inulin neoseries fructan. Here, we report the isolation and functional analysis of the gene encoding asparagus 6G-FFT. * A cDNA clone was isolated from asparagus cDNA library. Recombinant protein was produced by expression system of Pichia pastoris. To measure enzymatic activity, recombinant protein was incubated with sucrose, 1-kestose, 1-kestose and sucrose, or neokestose. The reaction products were detected by high performance anion-exchange chromatography. * The deduced amino acid sequence of isolated cDNA was similar to that of fructosyltransferases and vacuolar type invertases from plants. Recombinant protein mainly produced inulin neoseries fructan, such as 1F, 6G-di-beta-D-fructofuranosylsucrose and neokestose. * Recombinant protein demonstrates 6G-FFT activity, and slight fructan:fructan 1-fructosyltransferase (1-FFT) activity. The ratio of 6G-FFT activity to 1-FFT activity was calculated to be 13. The characteristics of the recombinant protein closely resemble those of the 6G-FFT from asparagus roots, except for a difference in accompanying 1-FFT activity.

Pentacene field-effect transistors(FETs) were fabricated on a poly(vinyl alcohol) (PVA)-coated Ta 2 O 5 gate dielectric using Au source/drain electrodes. Their device characteristics were examined before and after annealing the FETs in a vacuum. Before annealing, the pentacene FET showed an ambipolar operation with hole mobility of 0.1 cm 2 V − 1 s − 1 and electron mobility of 0.005 cm 2 V − 1 s − 1 . After annealing at 50 ° C , however, the p -type operation characteristics almost diminished and an enhanced n -type operation was observed. Na + ions in the PVA are supposed to change the character of the injection barrier at the Au/pentacene junction and enable the n -type operation.

We developed a nanoscale orientation template for quasisingle crystalline epitaxial growth of thin film phase pentacene. By using alpha-3x3 Bi termination of surface dangling bonds on step-bunched vicinal surface of Si(111), thin film phase epitaxial pentacene was grown with the crystal axes aligned to the surface steps. Alignment occurred when the step height was higher than the molecular height. The mechanism of the alignment was examined by calculating the energy of the crystal edge.

Electrolytically polished surfaces of Ta sheets were anodized in an aqueous KI solution to form Ta_2O_5 films with a relatively high dielectric constant and a high breakdown electric field. Organic field-effect transistors (OFETs) were fabricated on these Ta_2O_5/Ta substrates with a bottom gate configuration. The Ta_2O_5 films anodized at 100 V were about 200 nm thick, and the dielectric strength was as high as 5 MV/cm. A p-type pentacene OFET fabricated on this bottom gate showed the good field-effect mobility of 0.35 cm(2)/V s. By using this high-k gate substrate, it becomes possible to inject a higher amount of charge carriers into organic active layers than on the SiO_2/Si gate conventionally used in most OFETs.

The epitaxial growth of pentacene on hydrogen-terminated Si(111) is reported. Reflection high energy electron diffraction (RHEED) revealed that the crystal packing resembles that in the bulk crystal even at a monolayer thickness, which was maintained in multilayers. A ripening effect was clearly observed by atomic force microscopy (AFM). These results are important to obtain oriented crystalline films of pentacene combined with silicon microdevices with reduced defect densities. (c) 2005 American Institute of Physics.

Photolysis of a C6D6 solution of (η5-C5H5)Fe(CO)2SiMe2SiMeR2 (Fp-SiMe2SiMeR2; R=Me, Et) results in the formation of monosilyl-Fp derivatives with the scrambling of alkyl groups. Possible reaction pathways involving silyleneiron intermediates are discussed.

Photolysis of a C6D6 solution of CpFe(CO)2SiMe2SiMe3 (Cp=η5-C5H5) or (MeCp)Fe(CO)2SiMe2SiMe3 (MeCp=η5-C5H4Me) resulted in the formation of monosilyl derivative, CpFe(CO)2SiMe3 or (MeCp)Fe(CO)2SiMe3 in 64 or 59% yield, respectively, together with small quantities of ferrocene and Cp2Fe2(CO)4 or their methylated derivatives. The yield of CpFe(CO)2SiMe3 increased to 88% when the photolysis was carried out under a carbon monoxide atmosphere, while decreased to 22% when argon was vigorously bubbled through the reaction mixture. These results are consistent with a mechanism involving dissociation and recombination of a carbonyl ligand which are common processes in photoreactions of transition-metal carbonyl derivatives. Dimethylsilylene moiety released during the photolysis was tried to be trapped with a hydrosilane, diene, and cyclotrisiloxane, but none of the expected products from the trapping reactions was detected, even in a trace amount. Photolysis of CpFe(CO)2SiMe2SiMeEt2 afforded, accompanying alkyl mig...

Background Sugar beet molasses is a viscous by-product of the processing of sugar beets into sugar. The molasses is known to contain sucrose and raffinose, a typical trisaccharide, with a well-established structure. Although sugar beet molasses contains various other oligosaccharides as well, the structures of those oligosaccharides have not been examined in detail. The purpose of this study was isolation and structural confirmation of these other oligosaccharides found in sugar beet molasses. Results Four oligosaccharides were newly isolated from sugar beet molasses using high-performance liquid chromatography (HPLC) and carbon-Celite column chromatography. Structural confirmation of the saccharides was provided by methylation analysis, matrix-assisted laser desorption/ionaization time of flight mass spectrometry (MALDI-TOF-MS), and nuclear magnetic resonance (NMR) measurements. Conclusion The following oligosaccharides were identified in sugar beet molasses: β-D-galactopyranosyl-(1- > 6)-β-D-fructofuranosyl-(2 1)-α-D-glucopyranoside (named β-planteose), α-D-galactopyranosyl-(1- > 1)-β-D-fructofuranosyl-(2 1)-α-D-glucopyranoside (named1-planteose), α-D-glucopyranosyl-(1- > 6)-α-D-glucopyranosyl-(1 2)-β-D-fructofuranoside (theanderose), and β-D-glucopyranosyl-(1- > 3)-α-D-glucopyranosyl-(1 2)-β-D-fructofuranoside (laminaribiofructose). 1-planteose and laminaribiofructose were isolated from natural sources for the first time.

Background We have previously reported on the variation of total fructooligosaccharides (FOS), total inulooligosaccharides (IOS) and inulin in the roots of burdock stored at different temperatures. During storage at 0°C, an increase of FOS as a result of the hydrolysis of inulin was observed. Moreover, we suggested that an increase of IOS would likely be due to the synthesis of the IOS by fructosyltransfer from 1-kestose to accumulated fructose and elongated fructose oligomers which can act as acceptors for fructan:fructan 1-fructosyltransferase (1-FFT). However, enzymes such as inulinase or fructan 1-exohydorolase (1-FEH) involved in inulin degradation in burdock roots are still not known. Here, we report the isolation and functional analysis of a gene encoding burdock 1-FEH. Results A cDNA, named aleh1, was obtained by the RACE method following PCR with degenerate primers designed based on amino-acid sequences of FEHs from other plants. The aleh1 encoded a polypeptide of 581 amino acids. The relative molecular mass and isoelectric point (pI) of the deduced polypeptide were calculated to be 65,666 and 4.86. A recombinant protein of aleh1 was produced in Pichia pastoris, and was purified by ion exchange chromatography with DEAE-Sepharose CL-6B, hydrophobic chromatography with Toyopearl HW55S and gel filtration chromatography with Toyopearl HW55S. Purified recombinant protein showed hydrolyzing activity against β-2, 1 type fructans such as 1-kestose, nystose, fructosylnystose and inulin. On the other hand, sucrose, neokestose, 6-kestose and high DP levan were poor substrates. The purified recombinant protein released fructose from sugars extracted from burdock roots. These results indicated that aleh1 encoded 1-FEH.