bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of interphase and mitotic phosphorylation on the mobility and location of nucleolar protein B23
Authors: Negi Sandeep S. , Olson Mark O. J.
Published: August 2006

B23 (or nucleophosmin, NPM) is a multifunctional protein involved in ribosome biogenesis, control of centrosome duplication and in sensing cellular stress. It is phosphorylated during interphase by casein kinase 2 (CK2) and during mitosis by cyclin-dependent kinase (CDK). In this study we have addressed the role of these phosphorylation events in the dynamics and location of protein B23. Mutation of the CK2 phosphorylation site to alanine results in slower recovery of the mutant compared with the wild-type protein as measured by fluorescence recovery after photobleaching (FRAP). Immunofluorescence studies using an antibody against phosphorylated Thr199 revealed that B23 is phosphorylated at this CDK1 site at the start of mitosis and is dephosphorylated during anaphase. The CDK1-type phosphorylation sites are in the nucleic acid binding region of B23 and may contribute to its dissociation from the nucleolus during mitosis. A Thr to Glu mutant of the CDK1-type sites as well as other members of the nucleoplasmin family that lack the C-terminal nucleic-acid-binding region showed a greater mobility and/or faster recovery than wild-type B23.1, the longer variant. These results provide evidence that phosphorylation at these sites reduces the affinity of B23 for nucleolar components and might be a factor in regulating its location during the cell cycle.
Structure and function of nucleus-vacuole junctions: outer-nuclear-membrane targeting of Nvj1p and a role in tryptophan uptake
Authors: Kvam Erik , Goldfarb David S.
Published: August 2006

Nvj1p resides in the outer nuclear membrane (ONM) and binds the vacuole membrane protein Vac8p to form nucleus-vacuole (NV) junctions in Saccharomyces cerevisiae. The induction of NVJ1 expression during starvation results in the sequestration of two additional binding partners, Tsc13p and Osh1p. Here, we map the domains of Nvj1p responsible for ONM targeting and partner binding. ONM targeting requires both the N-terminal signal anchor-like sequence and the topogenic membrane-spanning domain of Nvj1p. The N-terminal signal anchor-like sequence may anchor Nvj1p in the ONM by bridging to the inner nuclear membrane. A region encompassing the membrane-spanning domain is sufficient to bind Tsc13p. Osh1p and Vac8p bind to distinct regions in the cytoplasmic tail of Nvj1p. Overexpression of Nvj1p in trp1 cells causes a growth defect in low tryptophan that is rescued by additional copies of TAT1 or TAT2 tryptophan permeases. Conversely, nvj1-Δ trp1 cells grow faster than NVJ1+ trp1 cells in limiting tryptophan. Importantly, deleting the Osh1p-binding domain of Nvj1p abrogates the tryptophan transport-related growth defect of Nvj1p-overexpressing cells. Therefore, the Nvj1p-dependent sequestration of Osh1p negatively regulates tryptophan uptake from the medium, possible by affecting the trafficking of tryptophan permeases to the plasma membrane.
Phospho-specific binding of 14-3-3 proteins to phosphatidylinositol 4-kinase III β protects from dephosphorylation and stabilizes lipid kinase activity
Authors: Hausser Angelika , Link Gisela , Hoene Miriam , Russo Chiara , Selchow Olaf , Pfizenmaier Klaus
Published: August 2006

Phosphatidylinositol-4-kinase-IIIβ (PI4KIIIβ) is activated at the Golgi compartment by PKD-mediated phosphorylation. Subsequent mechanisms responsible for continuous PtdIns(4)P production at Golgi membranes and potential interaction partners of activated PI4KIIIβ are unknown. Here we identify phosphoserine/-threonine binding 14-3-3 proteins as novel regulators of PI4KIIIβ activity downstream of this phosphorylation. The PI4KIIIβ-14-3-3 interaction, evident from GST pulldowns, co-immunoprecipitations and bimolecular fluorescence complementation, was augmented by phosphatase inhibition with okadaic acid. Binding of 14-3-3 proteins to PI4KIIIβ involved the PKD phosphorylation site Ser294, evident from reduced 14-3-3 binding to a S294A PI4KIIIβ mutant. Expression of dominant negative 14-3-3 proteins resulted in decreased PI4KIIIβ Ser294 phosphorylation, whereas wildtype 14-3-3 proteins increased phospho-PI4KIIIβ levels. This was because of protection of PI4KIIIβ Ser294 phosphorylation from phosphatase-mediated dephosphorylation. The functional significance of the PI4KIIIβ-14-3-3 interaction was evident from a reduction of PI4KIIIβ activity upon dominant negative 14-3-3 protein expression. We propose that 14-3-3 proteins function as positive regulators of PI4KIIIβ activity by protecting the lipid kinase from active site dephosphorylation, thereby ensuring a continuous supply of PtdIns(4)P at the Golgi compartment.
Proton Transfer in the Ground and Excited Electronic States of 4-Methyl-2,6-diformylphenol : Role of Alcoholic Solvents
Authors: Das Ranjan , Mitra Sivaprasad , Mukherjee Samaresh
Published: August 2006

The effect of alcohols on the proton-transfer processes in the ground and excited states of 4-methyl-2,6-diformylphenol (MFOH) has been investigated experimentally by steady state and time resolved emission spectroscopy. It is shown that the large Stokes-shifted fluorescence band in alcohols is due to the 4-methyl-2,6-diformylphenolate anion (MFO−), except in the case of 1-butanol. In 1-butanol the single broad fluorescence band observed in the visible region is assigned to the partially ionized species; the emission is found to depend on the excitation wavelength. Dual emission is observed only in the case of 2,2,2-trifluoroethanol (TFE). At 77 K the emission spectrum is found to be contaminated with the phosphorescence spectrum. The spectral characteristics obtained reveal that MFOH in protic solvents exists in more than one structural form in both the ground and excited states.
ESR and ENDOR Studies of the 2-Methylbenzophenone Anion Radical: Unusual Spin Density Distribution due to a Sterical Hindrance by Methyl Substitution
Authors: Yamauchi Jun , Fujita Hideo
Published: August 2006

Well-resolved ESR and ENDOR spectra of the 2-methylbenzophenone anion radical were observed at low temperature in DMF. The hyperfine coupling constant values obtained are consistent with each other, and indicate an unusual spin-density distribution in a molecule that is largely different from that of the pristine benzophenone anion radical. The most characteristic is the nonequivalency on the two ortho-positions of the phenyl ring. These findings are also discussed based on a comparison with the case of the 2-methylphenyl phenyl nitroxide, and a lack of a free rotation of the phenyl rings is concluded.
Solvent-Probe NMR Imaging of Low-Density Polyethylene Rods: A Layered Structure Formed during the Molding Process
Authors: Okazaki Masaharu , Toriyama Kazumi
Published: August 2006

The spatial inhomogenuity of a linear low-density polyethylene rod shaped with a metallic mold was clearly imaged by the solvent-probe NMR imaging technique. Images with T2 contrast were obtained using the T2-flash sequence, which reflects the spatially resolved mobility of the solvent molecules absorbed in the polymer. The NMR image was very much dependent on the thermal history both during and after the molding process. These results were interpreted with the aid of the nuclear relaxation parameters of the matrix polyethylene determined by the high-resolution solid state NMR technique. It is suggested that the solvent-probe NMR imaging technique provides valuable information concerning the micro structure (domain structure) and its spatial distribution of a crystalline polymer.
Solvent Extraction of Trivalent Yttrium, Holmium, and Erbium by Novel Types of Acidic Organophosphonates
Authors: Ohto Keisuke , Inoue Katsutoshi , Goto Masahiro , Nakashio Fumiyuki , Nagasaki Takeshi , Shinkai Seiji , Kago Tokihiro
Published: August 2006

New types of acidic organophosphonates, HR with different hydrophobic groups, were synthesized in order to investigate their extraction behavior for heavy rare earth elements (Y3+, Ho3+, and Er3+) from aqueous acidic chloride media. Their physicochemical properties, such as aggregation in an organic diluent and the acid dissociation constants (Ka) in the aqueous phase, were also examined. These rare earth elements were supposed to be extracted according to the stoichiometric relation,

This idea and the extraction equilibrium constants (Kex) for each metal ion were evaluated. Both the extraction equilibrium constants and the separation factors (β) between these metal ions were found to be greater than those of commercial extractants. The correlation between the extractability of heavy rare earth elements, the selectivity among these elements and the chemical structures of these extractants are discussed from a qualitative perspective.
A Seven-Coordinate Structure of Iron(II)–Ethylenediamine-N,N,N′,N′-tetraacetato Complex as Determined by X-Ray Crystal Analysis
Authors: Mizuta Tsutomu , Wang Jun , Miyoshi Katsuhiko
Published: August 2006

A single-crystal X-ray analysis has revealed that the FeII–edta complex, formulated as Na2[Fe(edta)(H2O)]·2NaClO4·6H2O, has a seven-coordinate structure close to a mono-capped trigonal prism (C2v-CTP). The crystal data are as follows: Orthorhombic, Pmnb, a = 11.404(1), b = 23.573(2), c = 9.915(1) Å, and Z = 4. In the complex anion, edta serves as a hexadentate ligand with its two N atoms at a unique edge and four O atoms at the corners of a quadrilateral face, which is capped with a water molecule. The presence of the labile water molecule in the first coordination sphere accounts for the kinetic lability of the FeII–edta complex, which has been frequently pointed out. A qualitative comparison of the molecular structures was made between the seven-coordinate FeII– and FeIII–edta complex anions. The steric and electronic requirements for seven-coordination are also discussed concerning the transition-metal edta complexes.
Mechanism of Azo Coupling Reactions: Part XXXVI. The Relationship between the Structure and the Catalytic Activity of Anionic Phase-Transfer Catalysts in Azo Coupling Reactions
Authors: Iwamoto Hidetoshi , Kobayashi Hiroshi , Murer Pius , Sonoda Takaaki , Zollinger Heinrich
Published: August 2006

A series of 15 sodium arenesulfonates containing alkyl, hydroxyl or methoxyl groups was investigated for the phase-transfer catalysis of the azo coupling reaction of the 4-methoxybenzenediazonium ion (1) with 1,3,5-trimethoxybenzene (2) in a dichloromethane/water two-phase system, in which the yields, initial reaction rates and influence of the decomposition of the diazonium ion 1 were measured. The influence of counter anions on the partition coefficient (α) for the diazonium ion 1 in a dichloromethane/water system, and the effects of the solvent polarity and structure of counter anions on the reaction rates of the azo coupling of the diazonium ion 1 with N,N-dimethylaniline (4) and 1,3,5-trimethoxybenzene (2) in organic solvents and in dichloromethane/water system, were investigated. The symmetrical structure of the tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (TFPB) anion was proved to be an essential factor regarding the remarkably high α for the diazonium ion 1 ion-paired with TFPB. The looseness and tightness of ion pairs of highly desolvated diazonium ion 1 in a nonpolar organic media is one of the most significant factors concerning the reactivity of the diazonium ion 1 in a rate-limiting azo coupling with 4. In a reaction of the diazonium ion 1 with 2 in a dichloromethane/water system, however, the amount of saturated water and/or additives in the dichloromethane phase, which serves as a base for the rate-limiting deprotonation, becomes the most influential factor for an effective azo coupling reaction under phase-transfer catalysis conditions.
Reduction of Carbonyl Compounds with Hydrosilanes on Solid Acid and Solid Base
Authors: Onaka Makoto , Higuchi Katsumi , Nanami Hiroyuki , Izumi Yusuke
Published: August 2006

Hydrosilylations of carbonyl compounds were performed on the surfaces of solid acids and bases. Strongly acidic clays efficiently catalyzed the reduction of aldehydes and ketones with trialkylsilanes (e.g. Et3SiH) to afford symmetrical ethers or hydrocarbons, depending upon the characters of substituents around carbonyl groups. Reduction-resistant ketone like 4,4′-dimethoxybenzophenone was found to be reduced with Et3SiH under the catalytic influence of the highly acidic clay. In contrast, trialkoxysilanes (e.g. (EtO)3SiH) became labile in contact with solid base like hydroxyapatite, reducing a variety of carbonyl compounds to yield alkoxy(triethoxy)silane in good yields. It was revealed that besides fluoride salts, solid bases bearing mild basicity and relatively large surface areas can activate the trialkoxysilane enough for reduction of carbonyl functions.
Preparation and Structure of a Tetrasubstituted Derivative of N″-Cyanoguanidine, N,N,N′,N′-Tetrabenzyl-N″-cyanoguanidine
Authors: Shiba Ryuichi , Takahashi Miyuki , Shinozaki Hiraku , Ebisuno Toichi , Takimoto Michiaki
Published: August 2006

A tetrasubstituted derivative of N″-cyanoguanidine (CG), N,N,N′,N′-tetrabenzyl-N″-cyanoguanidine (TBCG), was prepared by a phase-transfer reaction of CG with benzyl chloride in a 25% (w/w) NaOH aq soln–dichloromethane using tetrabutylammonium hydrogensulfate as a catalyst. TBCG was identified by means of an elemental analysis, 1H- and 13C NMR spectroscopy, FD mass spectrometry and an X-ray crystal analysis. The crystal is monoclinic, space group P21/n, a = 10.231 (2), b = 14.158 (4), c = 17.231 (4) Å, β = 95.27 (4)°, V = 2483 (1) Å3, Z = 4, Dc = 1.189 g cm−3, μ (Mo Kα) = 0.66 cm−1. The final R value was 0.069 for 1196 reflections.
Mechanistic Study of Base-Promoted Rearrangement of 1,5-Dibromopentacyclo[5.3.0.02,5.03,9.04,8]decane-6,10-dione to 10-Oxa-9-oxopentacyclo[5.3.0.02,4.03,6.05,8]decane-3-carboxylic Acid
Authors: Hasegawa Takeshi , Nigo Tomohiro , Kuwatani Yoshiyuki , Ueda Ikuo
Published: August 2006

The conversion of 1,5-dibromopentacyclo[5.3.0.02,5.03,9.04,8]decane-6,10-dione (1) to 10-oxa-9-oxopentacyclo [5.3.0.02,4.03,6.05,8]decane-3-carboxylic acid (6) on treatment with 5% aqueous potassium hydroxide was shown to proceed through 1, exo-7-dibromo-9-oxotetracyclo[4.3.0.02,5.03,8]nonane-endo-4-carboxylic acid (2). Treatment of 1 with the base in heavy water gave rise to 2-d-6 deuterated at the 2-position, but 2 gave the protium analog 6 after the same treatment. These results are discussed in relation to reactions of similar compounds which have been previously described in the literature.
Lewis Acid Coordinated Nitrile Oxide and Nitrile Imine 1,3-Dipoles. syn-Selective Cycloadditions to 2-(1-Hydroxyalkyl)acrylates
Authors: Kanemasa Shuji , Kobayashi Shigeru
Published: August 2006

Treatment of carbohydroximoyl chlorides with organometallics or carbohydrazonoyl chlorides with metal alkoxides or amides offers a new generation of Lewis acid-coordinated nitrile oxide and nitrile imine 1,3-dipoles, respectively. These 1,3-dipole/Lewis acid complexes undergo syn-selective cycloaddition reactions to 2-(1-hydroxyalkyl)acrylates through a chelated transition state, while free dipoles show anti-selectivities.
Stereoselective Introduction of Fluorine Atom: Synthesis of Racemic Carbocyclic Analogues of 3′-Deoxy-3′-fluororibofuranosides and 3′-Deoxy-3′-fluoroarabinofuranosides
Authors: Morizawa Yoshitomi , Nakayama Toshiaki , Matsumura Yasushi , Uchida Keiichi , Yasuda Arata
Published: August 2006

New carbocyclic analogues of nucleoside analogues substituted at the 3′-position with fluorine atom have been synthesized. Racemic carbocyclic 3′-deoxy-3′-fluoroarabinofuranoside analogue (3) has been prepared in several steps beginning with the regio- and stereoselective ring opening of (1α,2α,3α,4α)-4-acetamido-2,3-epoxycyclopentylmethylacetate (1). On the other hand, the corresponding carbocyclic analogue of fluororibofuranosyl derivative (14) has been obtained by SN2 displacement of siloxy group at 3′-position with piperidinosulfur trifluoride followed by removal of benzyl protecting group. The obtained sugar moiety 3 and 14 were transformed into the nucleoside derivatives respectively.
Vinyl Anion Equivalents. Part IV. Efficient Synthesis of 2-(1-Hydroxyalkyl)-2-cyclopenten-1-ones
Authors: Kusuda Shinya , Ueno Yoshio , Toru Takeshi
Published: August 2006

Aldol reactions of lithium enolates resulted from conjugate additions of tributylstannyllithium to 2-(phenylseleno)-2-cyclopenten-1-one provides 2-(1-hydroxyalkyl)-2-cyclopenten-1-ones in high yields. Significantly good 1,4-asymmetric induction took place in analogous aldol reactions starting with chiral 4-[(t-butyldimethylsilyl)oxy]-2-(phenylseleno)-2-cyclopenten-1-one.
Interaction of Polyelectrolyte with a Cationic Surfactant with an ω-Hydroxyl Group
Authors: Hayakawa Katumitu , Fukuda Katsuki , Maeda Tamaki , Satake Iwao
Published: August 2006

The sodium salt of poly(styrenesulfonate) interacts with the 12-hydroxydodecyltrimethylammonium cation anticooperatively. A data analysis of the dependence of the anticooperative binding constant on the NaCl concentration indicates an exchange reaction of the surfactant ion with the sodium ion.
Dependence of the Heat of Immersion of Maghemite on the pH of an Aqueous Solution
Authors: Watanabe Haruo , Seto Jun’etsu , Nishiyama Yoshiyuki
Published: August 2006

We examined the dependence on the pH value of the heat of immersion of maghemite in an aqueous system, and confirmed the peculiar finding that the pH value at the minimum heat occurs not at PZC, but at a higher pH. The reason for this is the existence of two types of surface hydroxyl groups (basic and acidic) which comprise all of the surface hydroxyl groups on maghemite. Moreover, the heat required for the adsorption of a proton on the surface hydroxyl group is higher than that for its desorption.
An Improved Synthesis of 4-Hydroxy-2,4,6-cycloheptatrien-1-one (4-Hydroxytropone)
Authors: Ikeda Yukari , Mori Akira , Takeshita Hitoshi
Published: August 2006

4-Hydroxytropone was prepared in an overall yield of 61% from 5-hydroxytropolone via tosylation, LiAlH4-reduction, acetolysis with acetic trifluoroacetic anhydride in situ, and hydrolysis.
Temperature and Thermal Stress Distributions in a Tubular Solid Oxide Fuel Cell
Authors: Kanamura Kiyoshi , Takehara Zen-ichiro
Published: August 2006

The temperature and thermal stress distributions in two model cells for a tubular solid oxide fuel cell, which have a different thickness of the electrolyte, were calculated by the finite element method to demonstrate the effects of electrolyte thickness on the mechanical stability of fuel cells. When the cells were operated at a constant voltage, their energy conversion efficiency increased with decreasing thickness of the electrolyte. A larger amount of heat was generated in the cell having a thinner electrolyte, thus producing a larger thermal stress. These results indicates that an excellent preparation method for the highly ionic conductive electrolyte is essential to produce a fuel cell with high mechanical stability.
Crystal Structure of Ni(dmit)2 Salts with Ammonium Ions Possessing Hydrogen-Bond Accepting Site
Authors: Miyazaki Akira , Izuoka Akira , Sugawara Tadashi
Published: August 2006

Crystal structures of three Ni(dmit)2 salts, whose counter cations ((2-methoxyethyl)ammonium, morpholinium, N-methylmorpholinium) consist of both hydrogen-bond donating and accepting sites, are reported. Within these salts, the Ni(dmit)2 columns are structurally modulated by intermolecular hydrogen bonds between the –NH+ group of the cation and the =S group of the dmit ligand. The alignment and the overlapping modes of Ni(dmit)2 molecules are found to be mainly governed by the hydrogen bonding pattern.
A 59Co NMR Study of the Interactions of Some Cobalt(III) Complexes in Nematic Lyomesophases
Authors: Iida Masayasu , Miyagawa Yasuko , Kohri Sachiko , Ikemoto Yuhko
Published: August 2006

59Co NMR spectroscopy was used to study the interactions of cationic or neutral octahedral cobalt(III) complexes such as [Co(NH3)6]3+, [Co(en)3]3+ (en = ethylenediamine), [Co(NO2)(NH3)5]2+, and [Co(acac)3] (acac = acetylacetonato) with surfactants in their nematic liquid crystalline solutions. The specific interactions of the complexes with the surfactants were studied in a replacement of one surfactant by another that had a different polar group. The extent of the binding of these complexes was monitored through the 59Co quadrupole splittings. The relationship between the extent of the binding and the magnitude of the quadrupole splitting did not hold when comparing the three cationic complexes. A comparison between the potassium dodecanoate (KDodec)/tetradecyl (or decyl)trimethylammonium bromide (TDTMABr or DTMABr) and the cesium N-dodecanoyl-L-alaninate (CsDDA)/tetradecyltrimethylammonium bromide (TDTMABr) mixed surfactant systems in the interaction with [Co(NH3)6]3+ and [Co(en)3]3+ complexes showed that these complexes bind to the alaninate polar group through a weakly interacting site in the range of the intermediate composition of the mixed surfactants; such a kind of the binding was negligible or smaller in the dodecanoate system. [Co(acac)3] complex was solubilized to liquid crystals and the interactions with the surfactant depended on their polar groups in spite of the electric neutrality of the complex.
Adsorption of Metal Ions on Chitosan and Crosslinked Copper(II)-Complexed Chitosan
Authors: Inoue Katsutoshi , Baba Yoshinari , Yoshizuka Kazuharu
Published: August 2006

A fundamental investigation on the adsorption behavior of metal ions on chitosan from aqueous ammonium nitrate and hydrochloric acid solutions was conducted by batch-wise examining the effects by various factors: the pH, concentrations of ammonium nitrate and hydrochloric acid, and initial metal concentration on the amount of metals adsorbed. In order to prevent the dissolution loss of chitosan into an acidic aqueous solution, crosslinked copper(II)-complexed chitosan was prepared and its adsorption behavior was compared with that of the original chitosan. The amount of adsorption, not only of metal ions, but also of the hydrogen ion, was decreased by crosslinking in the adsorption from an ammonium nitrate solution. The decrease, however, was least for copper(II), compared with the other divalent metal ions examined: oxovanadium(II), zinc(II), nickel(II), and cobalt(II). It was considered that this result may be attributable to the “template” effect by the copper(II) ion, which was employed during crosslinking in order to protect the active adsorption site of chitosan from an attack by a crosslinking reagent. It was found that chitosan has an excellent loading capacity and a selectivity much greater than the commercial iminodiacetic acid type of chelating resin. A qualitative discussion is given concerning the excellent adsorption behavior. Contrary to the case of adsorption from an aqueous ammonium nitrate solution, no significant decreases in the distribution ratios were observed between the crosslinked copper(II)-complexed chitosan and the original chitosan regarding the adsorption of palladium(II) and platinum(IV) from hydrochloric acid.
A Novel Nucleophilic Substitution with Quinoline Derivatives. Synthesis of Quinolones and Pyrazolo[4,3-c]quinoline Derivatives
Authors: Mekheimer Ramadan , Ahmed Essam Kh , Khattab Ahmed F
Published: August 2006

Novel nucleophilic substitution in quinoline system utilizing 2-chloro-4-piperidino-3-quinolinecarbonitrile (1) and 4-piperidino-2-oxo-1,2-dihydro-3-quinolinecarbonitrile (2) was reported. Some new quinolinones and pyrazolo[4,3-c]quinolines were synthesized.
Oxidative Generation of Thioalkyl Cations from 2-Tributylstannyl-1,3-dithianes and 1-(Tributylstannyl)alkyl Sulfides and Their Reactions with Olefinic Nucleophiles
Authors: Narasaka Koichi , Arai Noriyoshi , Okauchi Tatsuo
Published: August 2006

2-Tributylstannyl-1,3-dithianes and 1-(tributylstannyl)alkyl sulfides are oxidized with ammonium hexanitratocerate(IV) or ferrocenium hexafluorophosphate to generate their cation radicals, which dissociate into the carbocations and tributylstannyl radical. The carbocations thus generated react with olefinic nucleophiles to afford the corresponding addition products in good yield.
Wagner–Meerwein Rearrangement of 4-Hydroxymethylpentacyclo[4.3.0.02,5.03,8.04,7]nonane to Pentacyclo[5.3.0.02,6.03,9.04,8]decane in Formic Acid
Authors: Hasegawa Takeshi , Kuwatani Yoshiyuki , Higuchi Hiroyuki , Ueda Ikuo
Published: August 2006

The cationic rearrangement of 1-bromo-4-[hydroxybis(4-methoxyphenyl)methyl]pentacyclo[4.3.0.02,5.03,8.04,7]nonane-9-spiro-2′-[1,3]dioxolane (1) in formic acid gave 4-bromo-1-formyloxy-10,10-bis(4-methoxyphenyl)pentacyclo[5.3.0.02,6.03,9.04,8]decane-5-spiro-2′-[1,3]dioxolane in 27% yield along with 5-bromo-9-formyloxy-10,10-bis(4-methoxyphenyl)pentacyclo[5.3.0.02,5.03,9.04,8]decane-6-spiro-2′-[1,3]dioxolane in 55% yield. The reaction of 1 with p-toluenesulfonic acid or hydrochloric acid in methanol also afforded 4-bromo-1-methoxy-10,10-bis(4-methoxyphenyl)pentacyclo[5.3.0.02,6.03,9.04,8]decane-5-spiro-2′-[1,3]dioxolane together with 5-bromo-9-methoxy-10,10-bis(4-methoxyphenyl)pentacyclo[5.3.0.02,5.03,9.04,8]decane-6-spiro-2′-[1,3]dioxolane. With respect to migration of the C4–C5 bond in the pentacyclo[4.3.0.02,5.03,8.04,7]nonane (homocubane) skeleton to pentacyclo[5.3.0.02,6.03,9.04,8]decane (D2h-bishmocubane), a rearrangement into the bishomocubane system in driven by a concomitant release of strain; also, the stability of the 4-homocubanemethyl cation intermediate may play an important role in determining the course of the cage expansion into the D2h-bishomocubane system. This reaction provides an attractive route for the synthesis of bishomocubane bridgehead alcohols and related compounds which are not easily accessible by other routes.
Substituent Effect Studies of Aryl-Assisted Solvolyses. II. The Acetolysis of 2-Phenyl-2-(substituted phenyl)ethyl p-Toluenesulfonates
Authors: Fujio Mizue , Maeda Yasuyuki , Goto Mutsuo , Saeki Yoshihiro , Mishima Masaaki , Tsuno Yuho
Published: August 2006

The substituent effect on the acetolysis of 2-phenyl-2-(substituted phenyl)ethyl p-toluenesulfonates had a nonlinear LArSR correlation and was explicable in terms of a competitive aryl-assisted mechanism involving the X-substituted phenyl-assisted () pathway and the unsubstituted phenyl-assisted () pathway. By the application of the iterative nonlinear least-squares method based on the LArSR Eq., the substituent effect on the overall kt was dissected into the best-fit kM correlation of ρM = −3.53 with rM = 0.60, and the kN correlation of ρN = −0.88 with σ0. The ρM and rM values for the effects of assisting aryl substituents are quite close to those of the 2-methyl-2-phenylpropyl system and the small ρN value with unexalted σ0 constant for the unassisting aryls is compatible to the remote β-aryl effect. The relative rates of competing pathways dissected based on the substituent effect analysis agreed completely with the ratio of respective aryl migration products determined by the 13C-tracer method. Exact rate-product correlation demonstrates that this system involves two discrete aryl-assisted pathways, and , which do not cross over.
The Structures of Bioactive Cyclodepsipeptides, Beauveriolides I and II, Metabolites of Entomopathogenic Fungi Beauveria sp.
Authors: Mochizuki Keiko , Ohmori Ken , Tamura Harumi , Shizuri Yoshikazu , Nishiyama Shigeru , Miyoshi Eiichi , Yamamura Shosuke
Published: August 2006

Among the cyclodepsipeptides, beauveriolides I (1) and II (2) have been isolated from the mycelium of Beauveria sp., and their stereostructures were elucidated by spectral analyses coupled with syntheses of the corresponding 3-hydroxyoctanoic acid derivatives. Beauveriolide I (1) exhibited moderate insecticidal activities against Spodoptera litura and Callosobruchus chinensis.
Footprint Catalysis. VIII. Molecular Imprinting for Footprint Cavities on an Active Clay Surface
Authors: Morihara Kensaku , Iijima Tomoko , Usui Hiromi , Shimada Toyoshi
Published: August 2006

Our molecular imprinting procedures were used for molecular footprint cavities formation on the surface of an amorphous clay mineral. The imprinting with a template, N-benzoylsulfonamide, generated footprint cavities on the surface of Japanese Active Clay (sulfuric acid-treated Japanese Acid Clay). The cavities showed specific catalysis toward transacylation of benzoic anhydride that served as a corresponding substrate. This finding provided an experimental clue to study the adsorption mechanism of the Active Clay surface that has hardly been defined so far. Additionally, our comments on the significance of footprint imprinting in chemical evolution are described briefly.
Palladium-Catalyzed Consecutive One-Pot Reaction of Acetylenes with Allyl Bromide and Organotin Compounds
Authors: Kosugi Masanori , Sakaya Takashi , Ogawa Shinji , Migita Toshihiko
Published: August 2006

Allyl bromide adds to a terminal acetylene under the palladium complex to give 1-bromo-1,4-pentadiene which can further react with organotin compounds without further addition of palladium complex to give 1-substituted 1,4-pentadiene. These two reactions involving different catalytic species can be composed into the consecutive one-pot process.
Spectrophotometric Determination of Vanadium as V(III) with Dibenzoylmethane
Authors: Chauhan Rakam Singh , Kakkar Lajpat Rai
Published: August 2006

A highly sensitive and selective method for the determination of trace amounts of vanadium is developed by effecting complexation of V(III), obtained on reduction of V(V) by dithionite, with dibenzoylmethane in neutral medium. The colored complex is extractable into chloroform, absorption maxima lying at 386 nm. The interfering effect of a large number of elements is eliminated completely, which leads directly to the determination of the metal ion present in traces in samples. The method obeys Beer’s law in the range 0—2.4 μg-V cm−3 with Sandell’s sensitivity of 2.46 × 10−3 μg-V cm−2. Metal to ligand ratio in the extracted species is determined as 1 : 3.
Polarographic Determination of In(III) and Cd(II) by pH Adjustment of a Potassium Chloride Medium
Authors: Kurotu Takuzo
Published: August 2006

A polarographic determination of In(III) and Cd(II), the reduction potentials of which are very close to each other, was investigated by a pH adjustment of a potassium chloride medium. The reduction wave of In(III) decreased linearly with the pH. At pH 7.0, the reduction wave of In(III) completely disappeared, while that of Cd(II) remained unchanged. This fact enables us to determine In(III) and Cd (II) separately; In(III) can be determined from the merged-wave height of In(III) plus Cd(II) by subtracting that of Cd(II), which can be directly determined.
Preparation and Properties of (η5-Pentamethylcyclopentadienyl)iron Cationic Complexes with Long-Chain Alkyl Groups
Authors: Hasegawa Yasuchika , Fujinami Tatsuo , Sakai Shizuyoshi
Published: August 2006

Organo-transition metal surfactants, (η5-pentamethylcyclopentadienyl)iron cationic complexes with long-chain alkyl groups were prepared and their characteristics such as surface tension, redox, and photo-decomposition are discussed.
Formation of a Hydrogen Atom from the Photodissociation of Hydrogen Peroxide at 193 nm
Authors: Inagaki Yousuke , Matsumi Yutaka , Kawasaki Masahiro
Published: August 2006

Doppler profiles of H atoms from the photodissociation of H2O2 at 193 nm were measured by a laser-induced fluorescence method at 121.6 nm. On the average, 149 kJ mol−1 of energy is released as translational energy, which corresponds to about to 60% of the available energy. Doppler width anisotropy data show that the anisotropy parameter, β, for the photofragment angular distribution is −0.26 ± 0.11. This result implies that the H2O2 Ã1A state is responsible for H atom formation.
The kth Radius of Gyration of Aa1, Aa2–BbCc Type Polymerization
Authors: Chia-chung Sun , Xing-cai Xiao , Xu-ri Huang , Ze-sheng Li
Published: August 2006

By means of polymer chemical kinetics and statistics, the combinatorial coefficient of the Aa1, Aa2–BbCc type distribution is factorized to approach the explicit expression of the mean square radius of gyration. Furthermore, a recursion formula for the evaluation of the kth radius of gyration is obtained.
Spectra Analysis of the XPS Core and Valence Energy Levels of Polyvinyl Alcohol by an ab initio MO Method Using the 1,3,5-Hexanetriol Molecule
Authors: Endo Kazunaka , Inoue Chiaki , Kobayashi Naoya , Higashioji Takuji , Nakatsuji Hiroshi
Published: August 2006

The X-ray photoelectron spectra of polyvinyl alcohol (PVA) were analyzed by an ab initio MO method using the 1,3,5-hexanetriol (HTO) molecule. The theoretical spectral patterns derived from the Gelius–Siegbahn model showed good agreement with the spectra observed between 0—30 eV. The present results suggest several new assignments for the XPS spectra. The core-level C1s peaks at 285.0 and 286.5 eV correspond to the C1s electron levels arising from the CH2 and CH(OH) groups, respectively.
Chemomechanical Transduction in an Oil–Water System. Regulation of the Macroscopic Mechanical Motion
Authors: Yoshikawa Kenichi , Magome Nobuyuki
Published: August 2006

Self-movement of an oil–water system induced by chemically-driven Marangoni instability was studied. Depending on the shape of the vessel and the amount of oil and water solutions, various modes of movement were generated, such as random, rotational, and ameba-like. The most significant finding is the realization of a spatially directed mechanical movement. The mechanism of such chemomechanical transduction is discussed in relation to an imbalance of the interfacial tension due to a nonlinear oscillation at the interface.
Ab Initio Study of Neutral and Cationic B12 and B13 Clusters
Authors: Kato Hiroshi , Yamashita Koichi , Morokuma Keiji
Published: August 2006

The geometries, electronic structures, and energies of the neutral and cationic B12 and B13 clusters were investigated by the ab initio molecular orbital method. Several planar and non-planar stationary structures were optimized for neutrals and cations of each cluster size. A characteristic C2v cyclic form with one atom in the middle was found to be stable for each cluster. While the D5d icosahedral B12+ was found to be the most stable, the triplet D5d icosahedral B12 was stable but energetically unfavorable than the C2v cyclic B12. All the three-dimensional structures considered for B13 and B13+ clusters were unstable.
Reduction of Benzaldehydes with Raney Alloys in an Alkaline Solution
Authors: Tsukinoki Takehito , Ishimoto Keiko , Tsuzuki Hirohisa , Mataka Shuntaro , Tashiro Masashi
Published: August 2006

The reduction of benzaldehyde (1a) with Raney alloys in a 10% aq NaOH solution afforded benzyl alcohol (2a) in various yields (17—81%). In this reaction benzoic acid was also obtained as a by-product at the same time. This suggests that a Cannizzaro reaction competes with the reduction. In a 10% aq Na2CO3 solution the reduction of 1a with Raney alloys proceeded under ultrasonic irradiation to give almost exclusively 2a. In addition, we almost could not observe a Cannizzaro reaction in these experiments based on a comparison with a reduction in a 10% aq NaOH solution. A crossed Cannizzaro reaction between formaldehyde and benzaldehyde did not occur in a 10% aq NaOH solution/THF/MeOH, but afforded the reductive coupling compound hydrobenzoin.
Theoretical Studies on Hydrogen Bonding Interactions between Peptide Units
Authors: Aida Misako
Published: August 2006

The hydrogen bonding interaction energies between peptide units were calculated using the ab initio MO method with the STO-3G, 7,3/2,1 and 6-31G basis sets and a correction of the basis set superposition errors (BSSE). The same systems were also investigated using an ab initio potential which has recently been developed and the AMBER potential, which is widely used. The energy profiles calculated using the ab initio potential are similar to those calculated using the 6-31G basis set. The distance and angle dependencies of the hydrogen bonding interactions are well represented by the ab initio potential. In contrast, they are not reproduced by the AMBER potential.
Excitation Functions of the Slow and Fast Groups of the Excited Hydrogen Atom Produced in e–H2 Collisions
Authors: Ogawa Teiichiro , Jinbou Youichi , Yonekura Nobuaki , Furuya Kenji , Nakashima Keiji
Published: August 2006

Excitation functions of the fast group of H*(n = 3,4) show two thresholds at 22—23 and about 27 eV. Their comparison indicates that the dissociation process through the 1Σu+(2pσu)(nlσg) states are relatively more important for H*(n = 4).
Energy Transfer between Anthracene Chromophore and Sexithiophene in Langmuir–Blodgett Assemblies
Authors: Dutta Ashim Kumar , Pal Amlan Jyoti , Misra Tridibendra Narayan
Published: August 2006

Excellent Langmuir–Blodgett (LB) films of 9,10-diphenylanthracene (DPA) and α,α-linked sexithiophene (6T) with arachidic acid (AA) can be formed on water subphase and can be transferred on to quartz substrates. Electronic absorption and emission spectra of these films have been studied and compared with those in solution. Results suggest formation of aggregates of DPA and 6T in LB films. 6T has been used as a quencher for the DPA donor fluorescence. It is shown that the efficiency of energy transfer from the donor to the acceptor decreases with the quadratic power of the distance separating them. Such quadratic dependence confirms that the donor excitation is delocalized.
Coordination of Some Simple Molecules onto W(CO)5 in the Gas Phase
Authors: Jyo-o Motohiro , Takeda Hideki , Omiya Kenji , Ishikawa Yo-ichi , Arai Shigeyoshi
Published: August 2006

In the gas phase at room temperature, the coordination process of NH3, C2H4, CF4, SF6, and Xe onto “naked” W(CO)5, selectively prepared by pulsed 355-nm laser photolysis of W(CO)6, was investigated by laser-based time-resolved infrared absorption spectroscopy. W(CO)5 reacted with these reactant gases, except for CF 4 and SF6, to make a simple coordination complex, W(CO)5(L), where L is NH3, C2H4, or Xe. The bimolecular rate constants for these reactions were (5.6 ± 0.6) × 106 Torr−1 s−1 for W(CO)5 + NH3, (2.8 ± 0.5) × 106 Torr−1 s−1 for W(CO)5 + C2H4, and (1.0 ± 0.3) × 105 Torr−1 s−1 for W(CO)5 + Xe. W(CO)5Xe was unstable owing to its weak interaction with the coordinatively unsaturated tungsten center, the unimolecular decomposition rate of which was about 1.0 × 105 s−1, but W(CO)5(NH3) and W(CO)5(η2-C2H4) were stable under our experimental conditions. The band shifts of C–O stretching modes observed in the coordination of NH3 as a typical σ-donor, C2H4 as a typical π-acceptor, and Xe as a weak σ-donor could interpreted by MO considerations.
Column Chromatographic Separation of Uranium(VI) with Poly(dibenzo-18-crown-6) from Hydrochloric Acid Medium
Authors: Mohite Baburao Shankarrao , Patil Jaykumar Malgonda , Zambare Dnyandeo Namdeo , Mali Umesh Ganpatrao
Published: August 2006

A very simple method has been developed for the column chromatographic separation of uranium(VI) using poly(dibenzo-18-crown-6). The adsorption studies were carried out from hydrochioric acid medium in the concentration range of 0.5—10.0 mol dm−3. The adsorption of uranium(VI) started from 3.0 mol dm−3 hydrochloric acid and was quantitative from 5.5—10.0 mol dm−3 hydrochloric acid. Various eluting agents such as hydrobromic acid, perchloric acid, sulfuric acid, acetic acid were used for the elution of uranium(VI). The capacity of poly(dibenzo-18-crown-6) for uranium(VI) was found to be 2.5 mmol g−1 of crown polymer. Uranium(VI) was separated from large number of elements from the binary as well as from multicomponent mixtures. The method was applied to the analysis of uranium from real samples.
General Synthesis, Spectroscopic Properties, and Dipole Moments of 2-Substituted Tropothiones
Authors: Machiguchi Takahisa , Hasegawa Toshio , Kano Yuichi
Published: August 2006

Several 2-substituted tropothiones (2,4,6-cycloheptatriene-1-thiones) having an electron-donating group (Me, Ph, NH2, NHMe, OH, OMe, or SMe) were synthesized by direct sulfurization from the corresponding tropones in a one-pot reaction. In contrast to the instability of the parent tropothione (1a), most of these 2-substituted derivatives were insensitive to air and were thermally stable compounds which can be handled at room temperature. These tropothione derivatives were characterized by spectroscopic and dipole moment measurements. The IR spectra showed ν(C=S) vibrations at around 1100—1040 cm−1. The UV-vis spectra displayed three π–π* transitions accompanied by n–π* transitions. The 400-MHz 1H NMR spectra of the thiones showed that only protons at the 7 position resonate well-separated downfield from the other ring protons due to the strong C=S anisotropy. In the 13C NMR (100.6 MHz) spectra, the C=S carbon signals appeared at < δ = 183 and the other ring carbons resonated at δ = 154—112. Variable-temperature 13C as well as 14N NMR spectroscopic studies clarified that 2-amino- and 2-(methylamino)tropothiones exist as an equilibrium mixture of the thione and enethiol structures in an approximate ratio of 64 : 36. This is different from the results of a previous investigation showing that the structures exist as the thione form exclusively. Dipole moments of some derivatives of 1a were measured and compared with those of the corresponding tropones. These tropothione derivatives obtained were more ionic than both the parent compound 1a and the corresponding tropones.
Reactivities of Stable Rotamers. XXXII. Chlorodecarboxylation of 3-(1,4-Dimethyl-9-triptycyl)-3-methylbutanoic Acid Rotamers
Authors: Oki Michinori , Taguchi Yasushi , Okamoto Toshiyuki , Miyasaka Tsutomu , Hamada Koji , Toyota Shinji , Yonemoto Katsumi , Yamamoto Gaku
Published: August 2006

Rotational isomers of the title carboxylic acid were treated with lead(IV) acetate in the presence of lithium chloride or benzyltriethylammonium chloride in benzene. The ap-isomer afforded a chloride, which was expected from normal chlorodecarboxylation, in addition to a cyclized compound, which was produced by radical addition to a near-by benzene ring. By contrast, the sc-isomer afforded no normal chloride, but a benzylic chloride, which was formed by hydrogen transfer to the radical site in the 9-substituent from the benzylic position, was the main product. In addition, an acetonyl ester of the original sc-carboxylic acid and a small amount each of 1-acetoxymethyl compound and an olefin were obtained. Possible mechanisms of formation of these compounds are discussed on the ground of the stability of the benzylic radical and participation of a methyl group.
Conjugate Addition of α-(Trialkylstannyl)alkyl Groups to α,β-Enones: Preparation of γ-Stannyl Ketones
Authors: Sato Tadashi , Tachibana Kazutaka , Kawase Akira , Hirose Tomokazu
Published: August 2006

The title reaction was examined under various conditions. The corresponding cuprates underwent 1,4-addition satisfactorily to afford γ-stannyl ketones.
Fulvestrant: Pharmacologic Profile Versus Existing Endocrine Agents for the Treatment of Breast Cancer
Authors: Buzdar Aman U , Robertson John FR
Published: August 2006

Objective:

To compare the pharmacologic profile of fulvestrant with that of tamoxifen and the aromatase inhibitors with respect to the choice of treatment for advanced breast cancer (ABC).

Data Sources:

Principal literature and review articles were obtained from MEDLINE (1991–March 2006). Key search terms included fulvestrant, tamoxifen, aromatase inhibitors, pharmacology, and breast cancer. Further data sources were identified from the bibliographies of selected articles.

Study Selection and Data Extraction:

English-language preclinical and clinical research and review articles reporting pharmacologic and safety data for fulvestrant, tamoxifen, and the aromatase inhibitors were evaluated to identify relevant information. Randomized clinical trial data were preferred over preclinical or Phase I and II trial data.

Data Synthesis:

A total of 52 clinical papers (including 10 reviews) and 17 clinical abstracts were evaluated reporting results from controlled Phase I–III studies and pilot studies. Eleven preclinical papers (including 2 reviews) and 6 preclinical abstracts were also included. Fulvestrant has little effect on sex hormone endocrinology, bone metabolism, and lipid biochemistry and appears unlikely to be the subject or cause of CYP3A4-mediated drug interactions. Tamoxifen has a protective effect on bone (due to its partial estrogen agonist activity) and reduces plasma low-density lipoprotein cholesterol but increases triglyceride levels. The aromatase inhibitors have variable effects on lipid profiles and sex hormone endocrinology but have detrimental effects on bone due to inhibition of estrogen synthesis. Drug interactions have been noted between tamoxifen and anticoagulants and tamoxifen and aromatase inhibitors, which may be due to CYP-mediated mechanisms.

Conclusions:

Fulvestrant appears to have little effect on sex hormone endocrinology, bone metabolism, and lipid biochemistry and is unlikely to be subject to or the cause of CYP3A4-mediated drug–drug interactions. As such, fulvestrant represents a valuable new endocrine therapy for the treatment of ABC and broadens the options available to clinicians in the treatment of this disease.
Physicians’ Perceived Knowledge of and Responsibility for Managing Patients’ Out-of-Pocket Costs for Prescription Drugs
Authors: Shrank William H , Asch Steven M , Joseph George J , Young Henry N , Ettner Susan L , Kholodenko Yelena , Glassman Peter , Kravitz Richard L
Published: August 2006

Background:

Most insurers in the US have implemented incentive-based formularies that rely on out-of-pocket costs to influence prescription drug utilization. Medicare Part D plans have broadly adopted such benefit designs.

Objective:

To evaluate physicians’ perceptions of their knowledge of formularies and out-of-pocket costs, factors that influence knowledge of costs, physicians’ perceived responsibility for helping patients manage their out-of-pocket costs for prescription drugs, and physicians’ perceptions of the role of pharmacists in managing these costs.

Methods:

A multiple-choice survey was mailed to a random sample of 1200 physician members of the California Medical Association; a phone survey of nonresponders was then conducted.

Results:

Of 1027 surveys delivered to correct addresses, 509 (49.6%) responses were received. Thirty-three percent of physicians reported that they were usually or always aware of patients’ formularies and 20% were usually or always aware of patients’ out-of-pocket costs for medications. Surgeons, emergency department physicians, and physicians that prescribe from more formularies than other physicians are less likely to be aware of patients’ out-of-pocket costs, while physicians in large practices and those who use computers to prescribe are more aware. While 91% of physicians agreed that it is important that patients’ out-of-pocket costs be managed, 40% somewhat or strongly agreed that it is their responsibility to help. Sixty-five percent of physicians believed that it is the responsibility of the pharmacist to be familiar with patients’ out-of-pocket costs.

Conclusions:

Physicians often lack the knowledge to assist patients in the management of their out-of-pocket costs for prescription drugs and they depend on pharmacists to help patients manage those costs. Computer order entry and resources available in large physician organizations improve physicians’ awareness of out-of-pocket costs when prescribing.