Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 78 , Issue 4
Showing 1-25 articles out of 25 articles from the selected issue
Award Accounts
The Chemical Society of Japan Award for Creative Work for 2003
  • Hideaki Oikawa
    2005 Volume 78 Issue 4 Pages 537-554
    Published: 2005
    Released: April 08, 2005
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    Recent studies on a novel C–C bond formation enzyme, Diels–Alderase, show that this unusual enzyme is involved in the biosynthesis of secondary metabolites. In this account, I describe studies related to Diels–Alderases including biomimetic synthesis, the biological utilization of the Diels–Alder reaction, and natural Diels–Alderases. The function and catalytic mechanism of natural Diels–Alderases, such as solanapyrone synthase, lovastatin nonaketide synthase, and macrophomate synthase, are of great interest due to the diversity of molecular skeletons in natural Diels–Alder adducts. The first structure analysis of macrophomate synthase provided information on detailed mechanisms regarding active site organization among the substrates, metal and amino acid residues, and regarding how to avoid product inhibition.
  • Osamu Niwa
    2005 Volume 78 Issue 4 Pages 555-571
    Published: 2005
    Released: April 08, 2005
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    The recent development of electroanalysis using carbon film electrodes and micro and nano-structured carbon film based electrodes is reviewed. Graphite-like carbon film was synthesized by various methods such as thermal chemical vapor deposition and the thermolysis of organic polymers. Highly stable diamond film electrodes with a wide potential window have been synthesized by using the plasma CVD process and then employed for electroanalysis. A carbon film consisting of electron cyclotron resonance (ECR) sputter-deposited carbon films containing a large portion of sp3 bonds was introduced. The film makes it possible to detect analytes with higher oxidation potential or electroactive species that foul the electrode surface after oxidation. ECR carbon film can be deposited at low temperature and is conductive without doping. Graphite-like carbon films have been formed in order to construct various microelectrodes and microarray electrodes by using photolithography and dry etching methods to meet the requirements for improving the detection limit and for miniaturizing electrochemical detectors for small volume samples. For example, carbon film fabricated into an interdigitated array (IDA) electrode has a very low detection limit for biochemicals such as catecholamines when used as an electrochemical detector for high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE). In contrast, composite carbon films containing various metal nanoparticles can be used for many analytes, including hydrogen peroxide and sugars. The films are deposited by the RF co-sputtering of metal and carbon. This is unlike other preparation methods such as the thermolysis of a polymer–metal complex or the electroplating of metal particles onto carbon film. The obtained carbon film contains 2–5 nm metal particles such as Pt, Ni, Cu, and Ir. The highly sensitive and extremely stable detection of hydrogen peroxide, which is known to be the product of various oxidase enzymatic reactions, was achieved with sputter-deposited carbon film in which Pt nano-particles were dispersed. In contrast, carbon films containing dispersed Ni and Cu nanoparticles provide a high electrocatalytic current for sugars such as glucose and lactose in alkaline solution. By using the film as a detection electrode for HPLC, one can obtain a lower detection limit for several sugars than when using bulk metal electrodes.
Accounts
  • Hisakazu Mihara, Sachiko Matsumura, Tsuyoshi Takahashi
    2005 Volume 78 Issue 4 Pages 572-590
    Published: 2005
    Released: April 08, 2005
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    The aggregation of peptides and proteins into amyloid fibrils is most commonly associated with a variety of serious diseases such as Alzheimer’s disease and the transmissible spongiform encephalopathies (prion diseases). Amyloid-like fibrils are undesirable states for proteins as biomolecules, however, these are fascinating nanoconstructs because of their highly ordered tertiary structure in which numerous β-stranded polypeptide chains align regularly. These kinds of fibrous peptides have the potential to be engineered into ones revealing basic insights into amyloid formation and protein folding, as well as developing novel peptidyl nanoscale materials. We have demonstrated that de novo designed peptides undergo self-initiated structural transition and fibril formation, showing representative properties of amyloid. Cofibril formation from two, three, or four peptide species with well-designed amino acid sequences was achieved, so that the charged residues within the β-strands were complementary to each other. This homologous recognition mechanism can be applied for the inhibition of the fibril formation. Meanwhile, cofibril formation indicates a possibility of functionalizing the fibrils by co-assembling of peptides with various elements to develop a fibrous peptide material as a well-ordered nanoconstruct. Another designing approach demonstrated the production of unique straight nanofibers with defined widths. The fibrils may make a nanoscaffold onto which a variety of functional groups can be arranged. The studies on engineering fibrous peptides will afford insight into desease-related amyloid formation and will help to develop nanoscale fibrous constructs.
BCSJ Award Article
  • Tomohiko Hamaguchi, Haruko Nagino, Katsunori Hoki, Hiroaki Kido, Tadas ...
    2005 Volume 78 Issue 4 Pages 591-598
    Published: 2005
    Released: April 08, 2005
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    Pyrazine-bridged trimeric and tetrameric oligomers of triruthenium clusters, [{Ru3O(CH3CO2)6(CO)(py)}-(μ-pz)-{Ru3O(CH3CO2)6(CO)}-(μ-pz)-{Ru3O(CH3CO2)6(py)2}]+ (1) and [{Ru3O(CH3CO2)6(CO)(py)}-(μ-pz)-{Ru3O(CH3CO2)6(CO)}-(μ-pz)-{Ru3O(CH3CO2)6(py)}-(μ-pz)-{Ru3O(CH3CO2)6(dmap)2}]2+ (2), were prepared (pz = pyrazine, py = pyridine, dmap = 4-dimethylaminopyridine). Trimer 1 and tetramer 2 show closely spaced 11 step-12 electron and 14 step-15 electron reversible redox waves, respectively, in their cyclic voltammograms in CH3CN. These compounds were designed specifically to incorporate the above-mentioned electrochemical behavior, using the unique redox properties characteristic of triruthenium clusters: (i) each Ru3 cluster unit generally exhibits four reversible single electron waves from Ru3IV,III,III to Ru3II,II,II state; (ii) the redox potentials of the cluster units strongly depend on the basicity of the ancillary ligand; (iii) redox potentials of the Ru3 cluster units vary by 300–500 mV depending on the presence or the absence of a carbonyl ligand on the cluster unit; (iv) in the negative potential region, electronic interaction through the bridging pyrazine between adjacent Ru3 units containing a carbonyl ligand makes the difference in redox potential of each unit larger. 1 and 2 were synthesized by linking Ru3 cluster units with the desired ancillary ligand set in the appropriate order.
Articles
  • Reiji Tanaka, Takuya Yokoyama, Kaori Sameshima, Tokuzo Kawase
    2005 Volume 78 Issue 4 Pages 599-603
    Published: 2005
    Released: April 08, 2005
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    The relative permittivity (εr) and the conductivity (κ) at a frequency (f) of 50 kHz, and the dynamic light-scattering were measured for ternary systems of (AOT + r·H2O) solved in cyclohexane, heptane, octane, decane, and dodecane at a temperature of 298.15 K as a function of the amount ratio (r) of water to AOT (r = [H2O]/[AOT]) up to the onset of percolation. The molality (m) of AOT for those solutions was 0.15 mol kg−1, and increased to 0.30 mol kg−1 for solutions with dodecane. By increasing r, spherical reversed micelles were formed at r ≈ 6 in straight-chain hydrocarbons. The light-scattering measurements indicated that the mean hydrodynamic diameter of the micelles increased with increasing r, showing a sigmoid curve. The growth of micelles was promoted in a longer chain hydrocarbon. The percolation transition occurred as the particles grew to a critical diameter of about 50 nm. On the other hand, the growth of particles in c-hexane was moderate, and percolation did not occur up to r = 90, where the solution turned turbid. The growth of particles found from light-scattering measurements was well correlated to dielectric observations.
  • Muhammad Rusdi, Yoshikiyo Moroi, Thein Hlaing, Keisuke Matsuoka
    2005 Volume 78 Issue 4 Pages 604-610
    Published: 2005
    Released: April 08, 2005
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    The surface tension was measured against the concentration of CnE8 (n = 14, 16, and 18) at temperatures of 298.2, 303.2, 308.2, 313.2, and 318.2 K, from which the critical micelle concentration (CMC) was determined. The CMC decreased with increasing carbon number at lower temperatures, where the decreasing rate became much smaller at higher temperatures. The CMC values were examined by pyrene fluorescence, and the I1/I3 ratio of the pyrene spectrum steeply decreased below the CMC, and finally reached a plateau at higher surfactant concentrations. The I1/I3 ratios indicate that the microenvironment of pyrene in the micellar region becomes more hydrophobic with increasing the alkyl chain of CnE8. The aggregation number by a static light-scattering method increased with increasing the alkyl chain at a definite temperature and with raising the temperature for all of the surfactants. The thermodynamic parameters (ΔG°, ΔH°, TΔS°) of the micelle formation were calculated from the temperature dependence of CMC and the aggregation number, and the micellization was found to be entropy-driven. The surface excess concentration (Γ) was also determined from the change in the surface tension with the concentration from which the molecular surface area (A) below the CMC was evaluated. The molecular surface areas suggest that longer monoalkyl ethers form a bi-molecular layer with the hydrophobic tail intruding inwards. The positive entropy change (Δs) for the surface adsorption decreased and stayed almost constant with increasing concentration for C14E8 and C16E8, while the change remained almost zero for C18E8 at whole concentrations below the CMC. These results suggest that the non-fully extended alkyl chain in the bulk could not well contribute to a positive entropy change upon adsorption, which results in a smaller decreasing rate in CMC with increasing carbon number of alkylchain for C16E8 and C18E8 compared with the decreasing rate for CnE8 with n less than 14.
  • I. I. Guseinov
    2005 Volume 78 Issue 4 Pages 611-614
    Published: 2005
    Released: April 08, 2005
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    Using addition theorems for Slater-type orbitals, obtained by the author with the help of complete orthonormal sets of Ψα-Exponential type orbitals (α = 1, 0, −1, −2, ...), the one-range addition theorems for arbitrary Yukawa-like central and noncentral interaction potentials and their first and second derivatives are established. The addition theorems derived for the interaction potentials and the Slater orbitals are especially useful for machine computations of arbitrary multielectron multicenter integrals that arise in the Hartree–Fock–Roothaan approximation, and also in the Hylleraas-correlated wave-function method, which play a significant role in the theory and applications to quantum mechanics of atoms, molecules, and solids. The obtained relationships are valid for arbitrary nonzero screening constants of the potentials.
  • Keishi Ohara, Wataru Mizukami, Aiko Tokunaga, Shin-ichi Nagaoka, Hidem ...
    2005 Volume 78 Issue 4 Pages 615-621
    Published: 2005
    Released: April 08, 2005
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    A kinetic study was performed for the free-radical scavenging actions of curcumin and half-curcumin, which has a half-structure of curcumin, in order to clarify the mechanism of free-radical-scavenging in curcumin. The second-order rate constants for radical-scavenging reactions of curcumin and half-curcumin were measured by a stopped-flow spectrophotometer in several organic solvents (methanol, ethanol, acetonitrile, chloroform, and benzene) and in aqueous Triton X-100 (5.0 wt %) micelle solutions at various pH. The difference in the rate constant and solvent dependence between curcumin and half-curcumin suggests that the enol structure with the intramolecular hydrogen-bond of curcumin strongly enhances the radical-scavenging activity. Furthermore, notable pH dependences were observed for the rate constants of curcumin and half-curcumin in micelle solutions, suggesting that the acid–base dissociation equilibrium of phenol-protons in curcumin and half-curcumin affects their radical-scavenging activities.
  • Yumi Takeuchi, Yutaka Amao
    2005 Volume 78 Issue 4 Pages 622-625
    Published: 2005
    Released: April 08, 2005
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    A biohydrogen production system, has been developed that couples sucrose hydrolysis by invertase and glucose dehydrogenase (GDH) and hydrogen production with a platinum colloid as a catalyst. The system uses the visible light-harvesting function of artificial Zn chlorophyll-a (Zn Chl-a), prepared from Mg Chl-a (obtained from Spilurina). When a sample solution containing sucrose, invertase, nicotinamide adenine dinucreotide (NAD+), Zn Chl-a, methylviologen (MV2+, an electron carrier), and platinum colloid was irradiated, continuous hydrogen production was observed with the irradiation time. The amount of hydrogen production was about 10.5 μmol after 4 h of irradiation under the optimum condition.
  • Yan-Hong Tang, Ye-Yan Qin, Zhao-Ji Li, Jian Zhang, Yao Kang, Rui-Feng ...
    2005 Volume 78 Issue 4 Pages 626-632
    Published: 2005
    Released: April 08, 2005
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    The substitution reaction of [Mo3S4(dtp)3(ClCH2COO)(py)] (dtp = diethyl dithiophosphate) or [Mo3S4(dtp)4(H2O)] with adipic acid or glutaric acid in N,N′-dimethylformamide (dmf) or dimethyl sulfoxide (dmso) dimerized two discrete Mo3S4 clusters into novel Mo(IV) cluster compounds [Mo3S4(dtp)3(L)]2[μ-OOC(CH2)nCOO-μ] (L = dmf, n = 4 for 1, n = 3 for 2; L = dmso, n = 3 for 3). Their structures have been determined by X-ray crystallography and spectroscopically characterized. Each molecule of these clusters consists of two incomplete cubane-type [Mo3S4(dtp)3(L)] units, and each unit is respectively coordinated to one dicarboxylate group of the same dicarboxylic acid. Intermolecular S···S and C–H···S contacts, observed in the crystal packing diagram, establish three infinite two-dimensional supramolecular architectures.
  • Wataru Sugimoto, Kazunori Ohuchi, Yasushi Murakami, Yoshio Takasu
    2005 Volume 78 Issue 4 Pages 633-637
    Published: 2005
    Released: April 08, 2005
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    The reaction of ethylenediamine with a colloidal suspension containing exfoliated H2Ti4O9 nanosheets was studied. Characterization of the product by X-ray diffraction, thermogravimetry-differential thermal analysis, elemental analysis, and solid-state 13C NMR revealed that two types of ethylenediamine–H2Ti4O9 intercalation compounds, namely, compounds with ethylenediamine in a mono-layer or a bi-layer arrangement, could be prepared depending on the synthetic conditions. The latter composite material is a novel intercalation compound with the ethylenediamine arranged in a bi-layer with one amine group attached to the interlayer surface of H2Ti4O9 as an ammonium cation (–NH3+) and the other group present in the interlayer space in a neutral state (–NH2).
  • Yoshinori Takano, Katsumi Marumo, Toshiomi Ebashi, Lallan P. Gupta, Ho ...
    2005 Volume 78 Issue 4 Pages 638-651
    Published: 2005
    Released: April 08, 2005
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    The present study reports on the bio-organic composition of a deep-sea venting hydrothermal system originating from arc volcanism; the origin of the particulates in hydrothermal fluids from the Suiyo Seamount in the southern Izu-Bonin (Ogasawara) Arc is discussed with regard to amino compounds. Chimney samples on deep-sea hydrothermal systems and core samples at Suiyo Seamount were determined for amino acids, and occasionally amino sugars. Two types of chimney samples were obtained from active hydrothermal systems by submersible vehicles: one was natural chimney (NC) on a hydrothermal natural vent; the other was artificial chimneys (AC), mainly formed by the growth and deposition of sulfide-rich particulate components in a Kuwabara-type in situ incubator (KI incubator). Total hydrolyzed amino acids (THAA) and hydrolyzed hexosamines (HA) in AC ranged from 10.7 nmol/g to 64.0 nmol/g and from 0 nmol/g to 8.1 nmol/g, respectively, while THAA in hydrothermally altered core samples ranged from 26.0 nmol/g to 107.4 nmol/g-rock. The THAA was thus of the same order of magnitude in AC and core samples. The representative biochemical indicator ratios of β-alanine/aspartic acid and γ-aminobutyric acid/glutamic acid were low. This is consistent with a large microbial population and labile subterranean biogenic organic compounds. A micro energy dispersive X-ray spectrometer (μEDX) was used to show that the formation of massive pyrite- and chalcopyrite-ores, the major matrixes of the natural chimney structures, were processed during hydrothermal activity. These data suggest that labile particulate organic matter (POM) and/or dissolved organic matter (DOM) from hydrothermal fluid were continuously trapped to form concentrated organic matter in a sulfide-rich matrix.
  • Yasuki Yoshimura
    2005 Volume 78 Issue 4 Pages 652-658
    Published: 2005
    Released: April 08, 2005
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    The effect of NaClO4 on fac- and mer-isomers of tris(amino acidato)cobalt(III) ([Co(aa)3]) was examined by determining their solubilities in aqueous NaClO4 solutions. An addition of NaClO4 increased the solubilities of both the isomers of [Co(aa)3] except for tris(glycinato)cobalt(III) ([Co(gly)3]). While the solubility of mer-[Co(gly)3] was also increased by the addition of NaClO4, NaClO4 brought about abnormally large decrease in the solubility of fac-[Co(gly)3]. The addition of NaClO4 also produced a decrease in the solubility of tris(acetylacetonato)cobalt(III) ([Co(acac)3]). The salting-out effect of NaClO4 on fac-[Co(gly)3] was compared with that on [Co(acac)3]. While both the enthalpy (ΔtrH°) and entropy of transfer (ΔtrS°) from water to aqueous NaClO4 solutions for [Co(acac)3] were positive, those for fac-[Co(gly)3] were generally negative. On the basis of these results, an origin for the salting-out effect of NaClO4 on fac-[Co(gly)3] is discussed.
  • Yanbei Zhu, Akihide Itoh, Eiji Fujimori, Tomonari Umemura, Hiroki Hara ...
    2005 Volume 78 Issue 4 Pages 659-667
    Published: 2005
    Released: April 08, 2005
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    A tandem preconcentration method using a chelating resin was exploited for simultaneous multielement determination of trace metals in seawater by inductively coupled plasma mass spectrometry (ICP-MS). In the first preconcentration step, 500 mL of seawater sample was adjusted to pH 6.0, and the adsorption of trace metals on 0.4 g of Chelex-100 resin in dry weight was carried out at 55 °C. After equilibrium, the resin was collected on a glass filter and rinsed with 30 mL of ammonium acetate solution (pH 6.0) to reduce major elements such as Na, K, Mg, and Ca that had been partly adsorbed on the resin. Then, trace metals on the resin were eluted with 7.5 mL of 2 M nitric acid and collected in a 30 mL polypropylene bottle. In the second preconcentration step, the mixture of the filtrate and the rinsing solution obtained in the first step was adjusted to pH 4.0, and metal adsorption on another 0.4 g of Chelex-100 resin was carried out at 20 °C. In a similar manner to the first step, the resin collected on a glass filter was rinsed with 10 mL of ammonium acetate solution (pH 4.0), and trace metals adsorbed on the resin were eluted with 6 mL of 2 M nitric acid. This eluate was taken into the same polypropylene bottle as used in the first step. The final sample volume thus obtained was 15 mL including 1.5 mL of internal standard solution. Then a 33-fold preconcentration factor was achieved, where the recoveries for 33 elements were larger than 80%. The analytical results for trace metals in coastal seawater reference material (CASS-4) were in fairly good agreement with the certified or information values after correction with the recovery values. The coastal seawater samples from the Ise Bay and the Take Island were also analyzed by the present method. The concentrations for 20 trace metals in the Ise Bay coastal seawater were found to be more than 2-fold larger than those in the Take Island coastal seawater, indicating considerable anthropogenic pollution in the Ise Bay area.
  • Junpei Kuwabara, Daisuke Takeuchi, Kohtaro Osakada
    2005 Volume 78 Issue 4 Pages 668-670
    Published: 2005
    Released: April 08, 2005
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    The crystal structure of a new complex, trans-[PdCl2(NH=CPh2N)2], shows an association of the two molecules via intermolecular N–H···Cl hydrogen bonds. The 1H NMR signal of the N–H hydrogen in CDCl3 changes its position depending on the concentration and temperature of the solution.
  • Takashi Sugimura, Masami Kagawa, Naoko Ohuchi, Kazutake Hagiya, Tadash ...
    2005 Volume 78 Issue 4 Pages 671-676
    Published: 2005
    Released: April 08, 2005
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    Four optically active cycloheptatriene derivatives carrying a methoxy group(s) at different positions were prepared by the 2,4-pentanediol-tethered Büchner reaction. In addition to the high stereoselectivity, the tether also controlled the regioselectivity in a good-to-high degree. Some of the products are unstable under acidic conditions, resulting in isomerization through a prototropic reaction or aromatization. The Brønsted acid promoted prototropic isomerization by regio- and stereoselective protonation and ensuing deprotonation, while the Lewis acid-catalyzed reaction provided an aromatized product via the norcaradiene tautomer.
  • Yasuyuki Ogawa, Kiichi Kuroda, Jun-ichi Matsuo, Teruaki Mukaiyama
    2005 Volume 78 Issue 4 Pages 677-697
    Published: 2005
    Released: April 08, 2005
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    The stereoselective synthesis of new 19-hydroxytaxoid 36, possessing a double-aldol skeleton was achieved by way of B to BC to ABC ring construction. Optically active 8-membered ring 6 corresponding to the B-ring of 19-hydroxytaxol has been synthesized in high yield from epoxyketo aldehyde 8 by intramolecular samarium(II) iodide-mediated double aldol cyclization. The bicyclic compound 5 corresponding to the BC ring system was prepared from the 8-membered ring 6 by successive trimethylaluminium-assisted stereoselective conjugated addition and intramolecular samarium(II) iodide-mediated double aldol cyclization. The ABC-ring system 4 was constructed by stereoselective homoallylation and pinacol coupling cyclization with low-valent titanium. The synthesis of new 19-hydroxytaxoid 36 was accomplished from ABC ring system 4 by olefination of vicinal diol unit.
  • Osamu Ohtani, Toshio Itoh, Yuji Monna, Ryo Sasai, Tetsuya Shichi, Tats ...
    2005 Volume 78 Issue 4 Pages 698-702
    Published: 2005
    Released: April 08, 2005
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    Arenecarboxylate counterions, i.e., benzoate (BA) and p-t-butylbenzoate (p-t-BBA), were observed to be effective in facilitating E-to-Z photoisomerizations in cast films of 1:1 ion-pair salts of cationic surfactant azobenzene (C8AzoC10N+). Such an effect of the arenecarboxylate ions in C8AzoC10N+ salts showed a contrast to untreated, as-prepared bromide salts, which exhibited no such activity. A remarkable E-to-Z photoisomerization was observed to take place with the cast films of C8AzoC10N+ salts involving bulky anions, BA (or p-t-BBA); their photochromic behavior corresponded well with the aggregated structures of the 1:1 ion-pair salts. Analyses of the π–A isothermal profiles, XRD, and UV–vis spectroscopic investigations showed that C8AzoC10N+-Br stacked films form densely packed interdigitated monolayers, whereas films of the C8AzoC10N+-salt with BA (or p-t-BBA) were found to form loosely packed monolayers.
  • Taku Nakano, Kanae Ohto, Fumito Okafuji, Yoshihiro Mori, Hiroko Kakuda ...
    2005 Volume 78 Issue 4 Pages 703-709
    Published: 2005
    Released: April 08, 2005
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    In a model system of a water-soluble hemin, tetrakis(4-methylpyridyl)porphinatoiron(III) pentachloride (FeTMPyPCl5), with 3-methyl-2-benzothiazolinone hydrazone (MBTH), superoxide anion radical (O2•−), hydrogen peroxide, and then hydroxyl radical were generated in a phosphate buffer solution (pH 6.0–7.5) under aerobic conditions. The hemin was degraded in this system. The reactive oxygen species were deduced from inhibition of the degradation by adding SOD and catalase, and one of them was trapped by 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a DMPO–hydroxyl radical adduct, which was detected by ESR. The mechanism for activating dioxygen and the degradation of hemin was examined, and it was proposed to be the initial one-electron reduction of hemin by MBTH forming a dioxygen complex and liberating superoxide as one of the routes during the reduction–autoxidation cycle in aqueous media.
  • Yusuke Nakashima, Toshio Shimizu, Kazunori Hirabayashi, Masanori Yasui ...
    2005 Volume 78 Issue 4 Pages 710-714
    Published: 2005
    Released: April 08, 2005
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    Each optical isomer of methaneseleninic acid (1a) was isolated as chiral crystals by recrystallization from methanol/toluene. The absolute configuration of one of the enantiomers was determined by X-ray crystallographic analysis, and the relationship between the absolute configuration and the circular dichroism spectra of 1a was clarified. The optically active seleninic acid (R)-1a was stable toward racemization in the solid state, although it racemized very rapidly in solution. Each enantiomer of 1a was obtained in bulk by chiral crystallization in the presence of a seed crystal or chiral solvents. The absolute configuration of optically active methanesulfinic acid (4) was also assigned by comparing its circular dichroism spectra with those of 1a.
  • Wen-Jie Tian, Yoshihiro Sasaki, Sheng-Di Fan, Jun-ichi Kikuchi
    2005 Volume 78 Issue 4 Pages 715-717
    Published: 2005
    Released: April 08, 2005
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    A molecular device, in which the catalytic activity of lactate dehydrogenase was controlled by a response of ditopic molecular recognition of a lipid signal, was constructed on lipid bilayer membranes. The enzymatic activity was tuned up sensitively through phase transition of the matrix membrane as a platform for the intermolecular communication.
  • Katsuyuki Aoki, Chiharu Shimizu, Ikuhide Fujisawa
    2005 Volume 78 Issue 4 Pages 718-720
    Published: 2005
    Released: April 08, 2005
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    When tetraethylresorcin[4]arene is crystallized from dioxane, it forms a “head-to-head” arranged self-dimer directly connected by non-conventional O–H···π interaction. The resorcinarene molecule adopts the unusual flattened-cone conformation, where two of the four intramolecular hydrogen bonds are broken.
  • Daisaku Inoue, Masahiro Suzuki, Hirofusa Shirai, Kenji Hanabusa
    2005 Volume 78 Issue 4 Pages 721-726
    Published: 2005
    Released: April 08, 2005
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    A series of azobenzene derivatives containing glycine, L-alanine, L-valine, L-leucine, and L-isoleucine were synthesized and their gelation properties were examined. Although the azobenzene derivatives containing glycine, L-alanine, and L-leucine exhibited very low gelation abilities, other compounds of L-isoleucine and L-valine acted as good gelators that formed organogels in many organic solvents and oils at relatively low concentrations. The electron microscopic observation demonstrated that a three-dimensional network was created by entanglement of self-assembled nanofibers. Furthermore, the spectroscopic studies suggested that the gelator molecules self-assembled into the nanofibers through hydrogen bonding and π–π interactions, including the H-aggregation mode of the azobenzene segments.
  • Yasutaka Kitahama, Yasuyuki Kimura, Ken Takazawa, Giyuu Kido
    2005 Volume 78 Issue 4 Pages 727-730
    Published: 2005
    Released: April 08, 2005
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    An aqueous solution of 1,1′-diethyl-2,2′-quinocyanine bromide (PIC-Br) containing highly concentrated counter ions provided by NaCl was prepared by heating the solution at 90 °C. Upon cooling the solution to room temperature, it transformed into a gel-like state. Optical microscopy revealed that fiber-shaped J aggregates formed a network structure in the gelated solution. By cooling the solution in a magnetic field of 10 T, highly oriented J aggregates were obtained in the gel. Without any additional treatment, the alignment of the fibers was preserved after the gelated solution was removed from the magnetic field. The absorption spectra of the gelated solution showed a strongly polarized J-band, reflecting the high degree of orientation of the magnetically aligned J aggregates.
  • Hiroto Kudo, Naomi Inoue, Isao Nishimura, Tadatomi Nishikubo
    2005 Volume 78 Issue 4 Pages 731-737
    Published: 2005
    Released: April 08, 2005
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    In this paper, we describe the syntheses, properties, and photo-induced deprotection of β-CD derivatives containing t-butyl ester groups and fluorine atoms. The β-CD derivative was obtained from the reaction of β-CD and t-butyl-α-(trifluoromethyl)acrylate. The obtained β-CD derivative had excellent solubility, good film-forming property, high thermal stability, and good transmittance with the VUV spectra. When the photo-chemical reaction of the β-CD derivative was performed with a photo acid generator in the film state upon UV irradiation, it was found that the photoinduced deprotection of t-butyl ester groups and decomposition of acetal moieties of gluconopyranose unit proceeded smoothly. Furthermore, we examined the patterning property of the β-CD derivative as the photo resist using triphenylsulfonium fluorosulfonate as a photo acid generator, and 2-heptanone as the solvent. From this result, it was observed that the resolution of a 100 nm line and space pattern could be obtained.
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