bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing and Presenting Auditory Demonstrations: Two Sound Editor Programs
Authors: Firment Michael J.
Published: July 2006

Experiencing examples of auditory phenomena can clarify textbook and lecture explanations. The addition of visual displays to auditory demonstrations can make them more understandable. Two sound editor programs, Audacity and Adobe Audition Pro 2.0, provide excellent capabilities for the display and authoring of auditory demonstrations. Audacity possesses a considerable price advantage, whereas Audition has better capabilities for presenting and producing demonstrations.
Distinct roles for Hedgehog and canonical Wnt signaling in specification,differentiation and maintenance of osteoblast progenitors
Authors: Rodda Stephen J. , McMahon Andrew P.
Published: July 2006

Hedgehog and canonical Wnt/β-catenin signaling are implicated in development of the osteoblast, the bone matrix-secreting cell of the vertebrate skeleton. We have used genetic approaches to dissect the roles of these pathways in specification of the osteoblast lineage. Previous studies indicate that Ihh signaling in the long bones is essential for initial specification of an osteoblast progenitor to a Runx2+osteoblast precursor. We show here that this is a transient requirement, as removal of Hh responsiveness in later Runx2+,Osx1+ osteoblast precursors does not disrupt the formation of mature osteoblasts. By contrast, the removal of canonical Wnt signaling by conditional removal of the β-catenin gene in early osteoblast progenitors or in Runx2+, Osx1+ osteoblast precursors results in a similar phenotype: osteoblasts fail to progress to a terminal osteocalcin+ fate and instead convert to a chondrocyte fate. By contrast, stabilization of β-catenin signaling in Runx2+, Osx1+ osteoblast precursors leads to the premature differentiation of bone matrix secreting osteoblasts. These data demonstrate that commitment within the osteoblast lineage requires sequential,stage-specific, Ihh and canonical Wnt/β-catenin signaling to promote osteogenic, and block chondrogenic, programs of cell fate specification.
Proper patterning of the optic fissure requires the sequential activity of BMP7 and SHH
Authors: Morcillo Julian , Martínez-Morales Juan Ramon , Trousse Françoise , Fermin Yasmin , Sowden Jane C. , Bovolenta Paola
Published: July 2006

The optic disc develops at the interface between optic stalk and retina,and enables both the exit of visual fibres and the entrance of mesenchymal cells that will form the hyaloid artery. In spite of the importance of the optic disc for eye function, little is known about the mechanisms that control its development. Here, we show that in mouse embryos, retinal fissure precursors can be recognised by the expression of netrin 1 and the overlapping distribution of both optic stalk (Pax2, Vax1) and ventral neural retina markers (Vax2, Raldh3). We also show that in the absence of Bmp7, fissure formation is not initiated. This absence is associated with a reduced cell proliferation and apoptosis in the proximoventral quadrant of the optic cup, lack of the hyaloid artery, optic nerve aplasia, and intra-retinal misrouting of RGC axons. BMP7 addition to organotypic cultures of optic vesicles from Bmp7-/- embryos rescues Pax2 expression in the ventral region, while follistatin, a BMP7 antagonist, prevents it in early, but not in late, optic vesicle cultures from wild-type embryos. The presence of Pax2-positive cells in late optic cup is instead abolished by interfering with Shh signalling. Furthermore, SHH addition re-establishes Pax2 expression in late optic cups derived from ocular retardation (or) embryos, where optic disc development is impaired owing to the near absence of SHH-producing RGC. Collectively, these data indicate that BMP7 is required for retinal fissure formation and that its activity is needed, before SHH signalling, for the generation of PAX2-positive cells at the optic disc.
Dynamic and reversible restructuring of the ER induced by PDMP in cultured cells
Authors: Sprocati Teresa , Ronchi Paolo , Raimondi Andrea , Francolini Maura , Borgese Nica
Published: July 2006

In many cells, the endoplasmic reticulum (ER) contains segregated smooth and rough domains, but the mechanism of this segregation is unclear. Here, we used a HeLa cell line, inducibly expressing a GFP fusion protein [GFP-b(5)tail] anchored to the ER membrane, as a tool to investigate factors influencing ER organisation. Induction of GFP-b(5)tail expression caused proliferation of the ER, but its normal branching polygonal meshwork architecture was maintained. Experiments designed to test the effects of drugs that alter ceramide levels revealed that treatment of these cells with Phenyl-2-decanoyl-amino-3-morpholino-1-propanol-hydrocholride (PDMP) generated patches of segregated smooth ER, organised as a random tubular network, which rapidly dispersed after removal of the drug. The effect of PDMP was independent of its activity as sphingolipid synthesis inhibitor, but could be partially reversed by a membrane-permeant Ca2+ chelator. Although the smooth ER patches maintained connectivity with the remaining ER, they appeared to represent distinct domains differing in protein and lipid composition from the remaining ER. PDMP did not cause detachment of membrane-bound ribosomes, indicating that smooth ER patch generation was due to a reorganisation of pre-existing ribosome-free areas. Our results demonstrate a dynamic relationship between smooth and rough ER and have implications for the mechanisms regulating ER architecture.
JUN siRNA regulates matrix metalloproteinase-2 expression, microvascular endothelial growth and retinal neovascularisation
Authors: Zhang Guishui , Fahmy Roger G. , diGirolamo Nick , Khachigian Levon M.
Published: July 2006

Transcription factors link changes in the extracellular environment with alterations in gene expression. As such, these molecules serve as attractive targets for intervention in pathological settings. Since JUN has been linked with microvascular disease in humans, we hypothesised that small interfering RNA (siRNA) targeting this immediate-early gene may be useful agents that suppress endothelial growth and neovascularisation. Here we show that Jun siRNA inhibits Jun mRNA and protein expression in murine microvascular endothelial cells, blocks cell proliferation and suppresses migration in a scratch-wound assay. It also inhibits three-dimensional tubular formation on basement membrane extracts and reduces angiogenesis in mice bearing Matrigel plugs as subcutaneous implants. Single intravitreal administration of Jun siRNA reduces neovascularisation in a murine model of proliferative retinopathy, and suppresses endothelial JUN and matrix metalloproteinase-2 (MMP-2) immunoreactivity in retinal vessels, data supported by its repression of MMP-2 expression and gelatinolytic activity in vitro. Co-administration of TGFβ with the siRNA reverses this neovascular inhibitory effect, which is in turn abrogated by cis-9-octadecenoyl-N-hydroxylamide, consistent with the involvement of a metalloproteinase such as MMP-2. Thus, JUN siRNA can serve as a specific inhibitor of aberrant endothelial and neovascular growth.
The dynamics of hylobatid bipedalism: evidence for an energy-saving mechanism?
Authors: Vereecke Evie E. , D'Août Kristiaan , Aerts Peter
Published: July 2006

When gibbons travel through the forest canopy, brachiation is alternated with short bipedal bouts over horizontal boughs. We know, from previous research, that brachiation is a very efficient locomotor mode that makes use of a pendulum-like exchange of energy, but to date, nothing is known about the dynamics of hylobatid bipedalism. We wondered if gibbons also make use of an efficient gait mechanism during bipedal locomotion. To investigate this, we calculated oscillations of the centre of mass (COM), energy fluctuations,recovery rates and power outputs from the 3D ground reaction forces. These ground reaction forces were collected during spontaneous bipedal locomotion of four untrained white-handed gibbons (Hylobates lar) over an instrumented walkway (with an AMTI force plate). Excursions of the COM are relatively large during hylobatid bipedalism and the fluctuations of potential and kinetic energy are largely in-phase. Together with the low inverted pendulum recovery rates, this points to a spring-mass mechanism during bipedal locomotion. Although the well-developed Achilles tendon of gibbons seems to be a good candidate for the storage and recoil of elastic energy, this is not supported by kinematical data of the ankle joint. Instead, we suggest that the knee extensor muscle tendon unit functions as an energy-saving mechanism during hylobatid bipedalism, but detailed anatomical data is needed to confirm this suggestion. At low speeds gibbons use either pendular or spring mechanics, but a clear gait transition as seen in most quadrupedal mammals is absent. At moderate to high velocities, gibbons use a bouncing gait, generally without aerial phases. This supports the view that aerial phases are not a prerequisite for spring-mass mechanics and reinforces the claim that duty factor alone should not be used to distinguish between a walk and run.
Dynamics of rapid vertical climbing in cockroaches reveals a template
Authors: Goldman Daniel I. , Chen Tao S. , Dudek Daniel M. , Full Robert J.
Published: July 2006

Rapid, vertically climbing cockroaches produced climbing dynamics similar to geckos, despite differences in attachment mechanism, `foot or toe'morphology and leg number. Given the common pattern in such diverse species,we propose the first template for the dynamics of rapid, legged climbing analogous to the spring-loaded, inverted pendulum used to characterize level running in a diversity of pedestrians. We measured single leg wall reaction forces and center of mass dynamics in death-head cockroaches Blaberus discoidalis, as they ascended a three-axis force plate oriented vertically and coated with glass beads to aid attachment. Cockroaches used an alternating tripod gait during climbs at 19.5±4.2 cm s-1,approximately 5 body lengths s-1. Single-leg force patterns differed significantly from level running. During vertical climbing, all legs generated forces to pull the animal up the plate. Front and middle legs pulled laterally toward the midline. Front legs pulled the head toward the wall,while hind legs pushed the abdomen away. These single-leg force patterns summed to generate dynamics of the whole animal in the frontal plane such that the center of mass cyclically accelerated up the wall in synchrony with cyclical side-to-side motion that resulted from alternating net lateral pulling forces. The general force patterns used by cockroaches and geckos have provided biological inspiration for the design of a climbing robot named RiSE(Robots in Scansorial Environments).
Spectrophotometric Studies of the Metal Chelates of 2-Aminomethyl-pyridine and Its Derivatives. II. The Preparation and Electronic Absorption Spectra of Some Nickel and Copper(II) Chelates of 6-Methyl-2-aminomethylpyridine and N-Methyl-2-aminomethylpyridine
Authors: Utsuno Shunji , Sone Kôzô
Published: July 2006

Fifteen chelates of nickel and copper(II), among which twelve are new, of 6-methyl-2-aminomethylpyridine (6-methyl-2-picolylamine=“mepic”) and N-methyl-2-aminomethylpyridine (picolylmethylamine=“pma”) were prepared, and the electronic absorption spectra of their aqueous solutions were measured. The spectra observed were practically those of the chelate ions [Cu L]2+, [Cu L2]2+, [Ni L]2+, [Ni L2]2+ (L=mepic or pma) and [Ni (pma)3]2+; [Ni(mepic)3]2+ was found to be unstable in solution, and to dissociate into [Ni(mepic)2]2+ and a ligand molecule. With the exception of [Cu(pma)]2+, the wave numbers of the absorption maxima (νmax) of these chelates were all smaller than those of the corresponding 2-aminomethylpyridine (2-picolylamine=“pic”) chelates as a result of the steric hindrance caused by methyl substitution in the ligands. The nature and degree of this steric hindrance in each chelate, and the probable structure of some of these chelates, can be studied by a comparison of the obtained spectra with one another and by the use of scale models of these chelates.
Microwave Spectrum of Carbonyl Selenide
Authors: Morino Yonezo , Matsumura Chi
Published: July 2006

The microwave spectra of the OCSe molecule have been measured for the ground and vibrationally excited states of a number of isotopic species under the natural abundance ratio. It was concluded from the results that the rs-structure is given by r(O–C)=1.157 Å and rs(C–Se)=1.708 Å, and that the general quadratic force field is represented by fR(CSe)=5.42, fr(CO)=15.38, fRr=0.68, and fα=0.286 md/Å.
The Effect of Triphosphate on the Crystallization of Strontium Sulfate
Authors: Naono Hiromitu
Published: July 2006

The inhibiting action of triphosphate on the crystallization of strontium sulfate has been investigated conductometrically. The crystallization of strontium sulfate is remarkably inhibited by a minute amount of triphosphate. A supersaturated solution of 0.02 m strontium sulfate is, in practice, completely stabilized in the presence of 3×10−5  m triphosphate. In this stabilized solution, the growth of the seed crystal of strontium sulfate has been examined. The growth of the seed suggests that, in the stabilized solution, the formation of the critical nucleus of strontium sulfate is inhibited by the action of triphosphate. By utilizing the relation between the nucleation rate of strontium sulfate and the concentration of triphosophate, it has been shown that triphosphate increases the energy of formation of the critical nucleus. On the other hand, the adsorption of triphosphate on the crystal surface of strontium sulfate is endothermic; the heat of adsorption is estimated to be 3kT per triphosphate from the temperature dependence on the adsorption isotherm. The heat of adsorption of triphosphate increases the energy of formation of the critical nucleus of strontium sulfate. It may, therefore, be concluded that the nucleation of strontium sulfate is inhibited by the adsorption of triphosphate. From the calculation of the collision between triphosphate and the embryo of strontium sulfate, it may be deduced that the adsorption of triphosphate is predominant in the initial stage of the formation of the embryo of strontium sulfate.
Spectrophotometric Determination of Fluorine with the PAC-Th Complex
Authors: Shimoishi Yasuaki , Hayami Tadashi
Published: July 2006

The method of determining micro amounts of fluorine is based on the bleaching of the thorium complex of 2-(1, 8-dihydroxy-3, 6-disulfo-2-naphthylazo)-phenoxyacetic acid (PAC) by fluoride ions, which are strongly coordinated to the thorium in the complex and with thus liberate the free PAC. The complex is composed of thorium and PAC in a 1 : 1 molar ratio. PAC has an absorption maximum at 525 mμ, while the thorium complex shows a maximum at 555 mμ. The determination is based on the decrease in the absorbance at 610 mμ. Beer’s law holds up to 30 μg fluoride ions per 25 ml. The optimum pH range is from 2.5 to 3.5. The apparent molar extinction coefficient is calculated to be 20000.
Studies of Diarylalkanes. V. The Benzylation of Benzene and Chlorobenzene with Benzyl or p-Chlorobenzyl Chloride under the Influence of Various Catalysts
Authors: Tsuge Otohiko , Tashiro Masashi
Published: July 2006

The benzylation of benzene and chlorobenzene with benzyl or p-chlorobenzyl chloride under the influence of various catalysts has been carried out in order to elucidate the relation between the cleavage reaction of the DPM and the Friedel-Crafts benzylation. In the aluminum chloride- or gallium chloride-catalyzed benzylation, the compositions of the equilibrium mixture are similar to those of the cleavage reaction. It has been suggested that, in the presence of such catalysts, the DPM formed at an initial stage is cleft with the catalyst, and that the same equilibrium relationship as has been postulated in the cleavage reaction is established. On the other hand, in the aluminum chloride-, gallium chloride-nitro compound complex or in indium chloride, which does not exhibit the ability to cleave the DPM, both the products and the isomer distributions are different. It has been estiablished that the isomer distributions in the benzylation are affected by the reactivity of the reactive species as well as by the catalytic ability to cleave the DPM. It has also been found that, under the influence of a strong catalyst such as the aluminum chloride - nitromethane complex, the relative reactivity of p-chlorobenzyl chloride on benzene is equal to that of benzyl chloride, while the reactivity of the former is about half that of the latter in the presence of such a weak catalyst as indium chloride.
Dimerization and Rearrangement of Diphenylcyclopropenone
Authors: Toshima Naoki , Moritani Ichiro , Nishida Shinya
Published: July 2006

The reaction of diphenylcyclopropenone with cyclopentadienylmagnesium bromide did not give the expected tertiary carbinol, but resulted in the formation of tetraphenylcyclopenta-dienone, tetraphenyl-p-benzoquinone, and tetraphenylpyrocatechol in 1%, 2%, and 8% yields respectively. When diphenylcyclopropenone was treated with a mixture of metallic magnesium and iodine, the same products were obtained in increased yields. Similarly, the treatment of diphenylcyclopropenone with sodium amalgam in isopropyl alcohol - acetic acid gave tetraphenyl-p-benzoquinone and tetraphenylpyrocatechol in 4% and 20% yields respectively. These results suggest that diphenylcyclopropenone gives pinacol, 1, l′-dihydroxy-2, 2′, 3, 3′-tetraphenyl-l, l′-bi-cyclopropenyl, under the reaction conditions, but the pinacol is too unstable to be isolated and rearranges to the benzene derivatives.
The Kinetics of the Vapor-Phase Ammoxidation of m-Xylene over Mixed Vanadium Catalysts
Authors: Ito Masatomo , Sano Ken-ichi
Published: July 2006

The kinetics of the vapor-phase ammoxidation of m-xylene over a chromium-vanadium catalyst and an antimony-vanadium catalyst, in which the atomic ratio of chromium or antimony to vanadium was unity, was studied in a flow system and compared with that over a vanadium catalyst. The reaction-rate data obtained were then correlated with the reaction kinetic model proposed for a vanadium catalyst. There was no great difference in the reaction rates of m-xylene over the various catalysts. The ratios of the specific rate constant of m-xylene to that of m-tolunitrile, kx/kM both mixed vanadium catalysts were considerably smaller than that for a vanadium catalyst. The relative ratio for the formation of m-tolunitrile from m-xylene, k1/kx, was nearly equal for a vanadium catalyst and a chromium-vanadium catalyst, but it was larger for an antimony-vanadium catalyst. The order of the relative ratio for the direct formation of carbon oxides and hydrogen cyanide from m-xylene was: vanadium catalyst>chromium-vanadium catalyst>antimony-vanadium catalyst. The order of the selectivity for the formation of isophthalonitrile from m-tolunitrile on these catalysts was similar to the order of kx/kM. It seems that those results may be ascribed to the weaker adsorptivity for m-xylene on mixed vanadium catalysts.
The Cobalt Carbonyl-catalyzed Hydroesterification of Acrylonitrile with Carbon Monoxide and Methanol in the Presence of a Small Amount of Hydrogen and a Limited Amount of Pyridine
Authors: Matsuda Akio
Published: July 2006

The present reaction was studied in connection with our preceding research on the hydroesterification of propylene (This Bulletin, 38, 710 (1965)). The cobalt carbonyl-catalyzed reaction was successfully carried out in the presence of a small amount of hydrogen and a limited amount of pyridine; methyl esters of α- and β-cyanopropionic acids were thus obtained, the former in a larger amount than the latter. As the temperature decreased or as the partial pressure of carbon monoxide increased, the selectivity of the reaction toward the methyl α-cyanopropionate grew larger. The reaction mechanism was mainly investigated by kinetic methods. The infrared spectra of the catalyst solutions were measured at −60°C with a low-temperature cell. It was found by the IR study that acylcobalt carbonyls were formed in the acrylonitrile solution of dicobalt octacarbonyl and pyridine when it was treated under the same conditions (temperature and pressure) as in the reaction. It was found from the results of kinetic studies that the mechanisms of reactions at temperatures above and below 100°C were different; each of these mechanisms was discussed.
The Direct and Alternating Current Polarography of ε-Aminocaproic Acid and Its Linear Oligomers via the Schiff Bases
Authors: Kobayashi Yoshinari
Published: July 2006

ε-Aminocaproic acid (ACA) and its linear oligomers were transformed with formaldehyde to the corresponding Schiff bases, which are polarographically active. The a. c. and d. c. polarographic behavior was almost same among ACA, its linear dimer and trimer, of which the half-wave potentials and peak potentials were identical within the range of experimental errors. In d. c. polarography the diffusion current constant was independent of the degree of polymerization, although the peak-current constant in a. c. polarography was influenced by the degree of polymerization and there existed no linear relationship between the concentrations and the peak currents. This electrode reaction was supposed to be a one-electron reduction. In the presence of ε-carprolactam, the N-hydroxymethylation of the compound interfered with the appearance of polarographic waves.
Studies of Phenyl Ether Derivatives. III. Friedel-Crafts Type Condensation Reactions of Some Phenyl Ether Derivatives
Authors: Oshima Akio
Published: July 2006

By treating the p, p′-disubstituted diphenyl ether with stannic chloride or sulfuric acid in some solvents, two sorts of substances were obtained. One was a compound, (ArCH2C6H5)2O (I), produced by the condensation of two molecules of the aromatic solvent and a molecule of the phenyl ether, the other was a self-condensation product (II) of the phenyl ether itself. Which product is obtained is dependent not upon the substituent in phenyl ether, but upon the sort of solvent. On the basis of the analytical data, molecular-weight measurements, UV- and IR-spectral analyses, and the results of pyrolyzing gas chromatography, the author has deduced the structures A and B for I and II respectively. He has inferred about the mechanism for these phenomena as follows: in each case the reaction can be regarded as a sort of Friedel-Crafts reaction. When the reactivity of the solvent molecule is high enough to bring about normal condensation, the compound (I) is produced. On the other hand, inter- and/or intra-molecular condensations take place between the phenyl ether molecules to yield the compound (II) when the reactivity of the solvent is rather low.
Solvent Effect under High Pressure. A Novel Procedure for the Estimation of the Activation Volume and an Abnormal Acceleration of Reaction under High Pressure
Authors: Kondo Yasuhiko , Tojima Hiroshi , Tokura Niichiro
Published: July 2006

In order to examine the relation between the effects of solvents and the effects of pressure on reaction rates, an apparatus for kinetic runs under pressure was constructed and the rates of the Menschutkin reaction were measured in various solvents under pressure. A graphical method for the calculation of an activation volume from experimental results was then developed and applied to these data. Experimental results in acetonitrile, methanol, and nitromethane showed a linear relation between log(kp⁄k1)⁄P  vs.  P, but in the case of benzene and nitrobenzene large deviations from the line, that is, abnormal accelerations due to pressure, were observed at 1200 and 1500 (kg·cm−2). Analyzing these data, it was concluded that this abnormal acceleration was due to a freezing of the solvent with the increase in pressure.
Coumarins. III. A Novel Synthesis of o-Hydroxybenzaldehydes
Authors: Amakasu Takeshi , Sato Kikumasa
Published: July 2006

The catalytic hydrogenation of salicyloyl chloride at a mild temperature gave a high yield of salicylaldehyde. A similar partial reduction of substituted salicyloyl chlorides provided the corresponding salicylaldehydes in appreciable yields. Attempts to prepare other isomeric hydroxybenzoyl chlorides were, however, unsuccessful. The relationship between the structure of salicyloyl chlorides and the ease of their conversion to salicylaldehydes is discussed. Moreover, the formylation of phenol with dichloromethyl methyl ether and the selective ortho-formylation are described.
Reaction Rates in Binary Mixed Solvents. III
Authors: Kondo Yasuhiko , Tokura Niichiro
Published: July 2006

The expressions for the activation energies in binary mixed solvents have been derived from the differentiation of the expressions for the rate constants in binary mixed solvents obtained in Part II of this series [Y. Kondo and N. Tokura, Bull. Chem. Soc. Japan, 40, 1433 (1967).] with respect to the temperature. The activation energies in mixed solvents have been expressed in terms of the activation energies of the pure solvents, the equilibrium constant, and the composition of the solvent. From comparison with the experimental results, the model used by the authors has been proved to be valid for a consideration of the effects of solvents on the reaction rates and the activation parameters in binary mixed solvents.
The Deamination of 3-Methylenecyclobutylcarbinylamine
Authors: Ooba Shigehiro , Kato Hiroshi , Ohta Masaki
Published: July 2006

The nitrous acid deamination of 3-methylenecyclobutylcarbinylamine in water gave 2-methylenecyclopentanol and 3-methylenecyclopentanol. The reduction of methyl 3-methylene-cyclobutanecarboxylate with lithium aluminum hydride gave 3-methylenecyclobutylcarbinol.
Studies on the κ-Polysaccharide of the Red Seaweed Gigartina Tenella
Authors: Hirase Susumu , Watanabe Kyoko
Published: July 2006

The polysaccharide extracted from the red seaweed Gigartina tenella has been separated into κ- and λ-polysaccharide by potassium chloride. The former polysaccharide is a gelling component precipitated with potassium chloride, while the latter is a non-gelling component insensitive to the precipitant. Complete hydrolysis and methanolysis, together with quantitative determination, have shown that the κ-polysaccharide is composed mainly of d-galactose, 3, 6-anhydro-d-galactose, and an ester sulfate in the molar proportion 1 : 0.98 : 1.17. Very small amounts of l-galactose and d-xylose have also been isolated from the products of hydrolysis. The partial methanolysis of the κ-polysaccharide yielded dimethyl acetal of carrabiose (4-O-β-d-galactopyranosyl-3, 6-anhydro-d-galactose) in a good yield. It follows from these results that this disaccharide is a chief repeating unit of the carbohydrate moiety of the polysaccharide, as in the case of κ-carrageenan.
Component Sugars of the Polysaccharide of the Red Seaweed Grateloupia Elliptica
Authors: Hirase Susumu , Araki Choji , Watanabe Kyoko
Published: July 2006

The extraction of Grateloupia elliptica with hot water afforded a mucilageous sulfated polysaccharide, which was then purified through precipitation as a complex with cetyl pyridinium chloride. In order to examine the component sugars, the polysaccharide was subjected to complete hydrolysis and methanolysis, the respective products of which were then carefully fractionated both by crystallization and chromatography in order to isolate the individual products. The results obtained, coupled with the data of quantitative estimation, have shown that the bulk of the polysaccharide is composed of d-galactose, l-galactose, 3, 6-anhydro-d-galactose, and sulfate, existing in the approximate molar proportion of 9 : 1 : 2 : 8. In addition to these main components, the presence of small amounts of d-xylose, 2-O-methyl-l-galactose, 4-O-methyl-d-galactose and 2-O-methyl-3, 6-anhydro-l-galactose has also been established. These compounds have been identified on the crystalline basis. The partially-methylated sugars isolated above have seldom or never previously occurred in polysaccharides.
Studies of the Organic Reactions of Metal Carbonyls. XI. The Reaction of Potassium Iron Carbonylates with Olefin Oxides
Authors: Takegami Yoshinobu , Watanabe Yoshihisa , Masada Hiromitsu , Kanaya Isao
Published: July 2006

The reaction between potassium iron carbonylates (KHFe(CO)4, K2Fe(CO)4, K2Fe2(CO)8, and K2Fe3(CO)11) and olefin oxides has been studied. Propylene oxide reacts readily with these carbonylates and carbon monoxide at atmospheric pressure at room temperature. As the reaction product, β-hydroxy-n-butyrate is obtained by the treatment of the reaction mixture with an iodine and hydrogen chloride solution in alcohol, indicating that a complex with a type of β-hydroxy-n-butyryliron carbonyl is formed in the reaction. Ethylene oxide also reacts with the carbonylate to give β-hydroxypropionate.
Studies of the Organic Reactions of Metal Carbonyls. XII. The Oxo Reaction of Ethyl Acrylate by Rhodium Carbonyl
Authors: Takegami Yoshinobu , Watanabe Yoshihisa , Masada Hiromitsu
Published: July 2006

The oxo reaction of ethyl acrylate by rhodium carbonyl has been studied and compared with that by cobalt carbonyl. The reaction conditions (the temperatures, and the partial pressures of carbon monoxide and hydrogen) affect the distribution of the products (α- and β-carbethoxy-propionaldehyde) more remarkably, but in a way similar to that in the reaction by cobalt carbonyl: the proportion of β-carbethoxypropionaldehyde increases greatly with an increase in the reaction temperature, but decreases with an increase in the partial pressure of carbon monoxide or hydrogen. Judging from this similarity, it is probable that rhodium carbonyl reacts with ethyl acrylate as rhodium hydrocarbonyl to give alkyl- and acylrhodium carbonyls in the course of the reaction.
The Isolation of Isomeric 5-Oxazolones and the Assignment of Their Structures by Means of NMR Spectroscopy
Authors: Iwakura Yoshio , Toda Fujio , Torii Yoshinori
Published: July 2006

In the syntheses of 5-oxazolones (2-isopropenyl-4-alkyl-2-oxazolin-5-ones) from N-meth-acryloyl-α-amino acids, new isomerized oxazolones were obtained. By NMR spectroscopy, the structures of isomerized oxazolones were determined to be pseudoxazolones (2-isopropylidene-4-alkyl-3-oxazolin-5-ones). The NMR spectra of several pseudoxazolones were measured and compared with the normal oxazolones.
10, 11-Dihydro-5H-dibenzo[a, d]cycloheptenylidene
Authors: Moritani Ichiro , Murahashi Shun-Ichi , Yoshinaga Kunio , Ashitaka Hidetomo
Published: July 2006

The photolysis of 5-diazo-10, 11-dihydro-5H-dibenzo[a, d]cycloheptene in cis-2-butene gave 5, 5′-bi(10, 11-dihydro-5H-dibenzo[a, d]cycloheptenyl) (81%), 10, 11-dihydro-5H-dibenzo[a, d]-cycloheptene (6%), and 10, 11-dihydro-5H-dibenzo[a, d]cyclohepten-5-one (6%). The ESR spectrum established the triplet ground state of this carbene. The absorption spectrum of this carbene was obtained successfully. These spectra are similar to that of diphenylmethylene. 5, 5-Dibromo-10, 11-dihydro-5H-dibenzo[a, d]cycloheptene was prepared by the bromination of the diazo compound at −30°C. The reaction of this dibromide with alkyllithium in the presence of olefin gave 5, 5′-bi(10, 11-dihydro-5H-dibenzo[a, d]cycloheptenylidene) and 5-alkyl-10, 11-dihydro-5H-dibenzo[a, d]cyclohepten-5-ol. No cyclopropane derivatives were obtained.
The Nuclear Magnetic Resonance Spectra of Olefinic Protons and the Substituent Effects. IV. Intramolecular Interactions between Substituents in trans-1,2-Disubstituted Ethylenes
Authors: Niwa Jun
Published: July 2006

The olefinic proton chemical shifts (δji), measured in parts per million from ethylene, in an extensive series of trans-1,2-disubstituted ethylenes (RjCHjiCHijRi) show uniform deviations from the simple additivity of the substituent-shielding parameters. These deviations may be attributed to the interactions between the Ri and Rj substituents, so the chemical shift, δji or δij, may be expressed as δji=dc(Ri)+dG(Rj)+Iji or δij=dc(Rj)+dG(Ri)+Iij. The abbreviations dc(Ri) and dG(Rj) represent the substituent-shielding parameters, while Iji and Iij represent the respective terms of the interactions. The chemical shifts, δji, in each series of compounds bearing Rj as an invariable substituent are determined by the Hammett’s σ-constants of Ri, and much more closely by dc(Ri). That is, δji=dG(Rj)+ρJσi, and δji=dG(Rj)+ρJ′dc(Ri), where the susceptibility, ρJ, is also related to ρJ′ by a linear function. By assuming that Iji is approximately equal to Iij, the following equations may be derived:

ρJ′−ρ0′=κσj and Iji=κσjdc(Ri)

The applicabilities of these equations were tested graphically for the 70 shifts in series of trans-1,2-disubstituted ethylenes. The results revealded that the chemical shift, δji or δij, was comprehensively expressed as:

δji=dG(Rj)+(−0.59σj+1.08)dc(Ri)

or δij=dG(Rt)+(−0.59σi+1.08)dc(Rj)

with the exception of those compounds bearing halogen substituents. The values of standard deviation and the correlation coefficient were 0.08 and 0.994 respectively.
Fluorenylidene and 2,7-Dibromofluorenylidene
Authors: Murahashi Shun-ichi , Moritani Ichiro , Nagai Toshikazu
Published: July 2006

Photolysis of 9-diazofluorene or 2,7-dibromo-9-diazofluorene in diethyl maleate or diethyl fumarate was found to give cyclopropane derivatives nonstereospecifically. Irradiation of 9-diazofluorene in 1,2-dichloroethylene gave no addition product, but did 9-chlorofluorene in 85–89% yield. The same reaction in carbon tetrachloride gave 9,9′-dichloro-9,9′-bifluorenyl in 48% yield. Thus fluorenylidene has strong abstraction character. These chemical results suggest that fluorenylidene and 2,7-dibromofluorenylidene react in triplet state. Furthermore the ground states of these carbenes were confirmed to be triplet by ESR spectra. Concerning to zero-field parameter little effect of bromine substituent was observed in 2,7-dibromofluorenylidene.
Studies of Organic Catalytic Reactions. V. The Function of the Chelates formed in the Hydrolysis of 2-Cyanopyridine with Metal Oxide Catalysts
Authors: Sakai Koji , Ito Takehiko , Watanabe Ken-ichi
Published: July 2006

When 2-cyanopyridine is refluxed with water in the presence of nickel or copper oxide, it is easily hydrolyzed and affords a chelate compound of the acid with nickel or copper. On the other hand, 3- or 4-cyanopyridine affords only the corresponding free amide by the same reaction. The interfering effect of thiophene is not observed in the reaction of 2-cyanopyridine, but it is observed in the case of the 3- or 4-cyanopyridine. When 2-cyanopyridine is refluxed with an aqueous solution of nickel or cupric chloride, it is hydrated to form a chelate of the amide with nickel or copper. These chelates are hydrolyzed with the metal oxides in water to afford the chelates of the acid. Pyridine-2-carboxylic acid amide is also hydrolyzed to the chelate of the acid, but the hydrolysis of the 3- or 4-amide isomer does not occur under the same conditions. The four chelates of the acid and amide are excellent catalysts for the hydration of 2-cyanopyridine, giving the free amide in a high yield. From these facts, it may be presumed that: 1) The adsorption of 2-cyanopyridine or its amide on the catalysts is stereospecific and results in the formation of a kind of chelate. Upon forming the acid, the metal atom of the catalyst is drawn out of the catalyst to form the chelate. 2) The metal oxide is the most suitable catalyst for the chelate-type adsorption and for the chelate formation. 3) The chelate of the acid formed during the hydrolysis of 2-cyanopyridine acts as another catalyst in the formation of the free amide, then, the amide is further converted into the chelate of the acid by means of the metal oxide catalyst.
Kinetic Studies of Solvolysis. XIV. The Solvolysis of Optically Active α-Phenylethyl Chloride in Binary Mixtures of Methanol and Phenol —The SN1 Methanolysis with the Retention of the Configuration—
Authors: Okamoto Kunio , Komatsu K\={o}ichi , Shingu Haruo
Published: July 2006

The competitive SN1 methanolysis and SN1 phenolysis of optically-active α-phenylethyl chloride in the presence of added triethylamine give α-phenylethyl methyl ether and α-phenylethyl phenyl ether, both with a net inverted configuration, in 50 wt% methanolic phenol, whereas in 85–95 wt% methanolic phenol both the methyl and the phenyl ether have been obtained with a net retained configuration. In the intermediate solvent range (e.g., 75 wt% methanolic phenol), the methyl ether possesses a net inverted configuration, while the phenyl ether has a net retained configuration. Over the entire solvent range examined, the o- and p-α-phenylethylphenols (the C-alkylation products) possess net inverted configurations. This heretofore unusual retained steric course of the methanolysis is explained by the SNi-like four-center attack of a methanol molecule from the retentive side of the SN1 ion-pair intermediate. Much as in the retentive hydrolysis in the aqueous phenols, the specific solvation of the phenol molecules to the SN1 ion-pair intermediate may be suggested as a factor which assists the retentive attack of the methanol molecule.
Oxidation of Methyl Conjugated Octadecadienoate with Monoperphthalic Acid
Authors: Suhara Yasuo , Shibuya Yoshinori , Otsuru Hideki
Published: July 2006

Methyl trans-9-trans-11-octadecadienoate was oxidized with monoperphthalic acid under various conditions. The products obtained were separated into several fractions by washing them with an alkaline solution and then submitting them to column chromatography. The substance thus obtained from each fraction was studied by chemical and spectroscopic procedures. From the results of chemical tests, periodic acid cleavage, and spectroscopic observation in the infrared and ultraviolet regions, it is inferred that the oxidation products in all cases contain all the methyl trans-9,10-epoxy-trans-11- and methyl trans-11,12-epoxy-trans-9-octadecenoates, methyl dihydroxy-trans-octadecenoate, and methyl 9(10)-hydroxy-10(9)-(o-carboxy)benzoyloxy-trans-11-and methyl 11(12)-hydroxy-12(11)-(o-carboxy)benzoyloxy-trans-9-octadecenoates.
Synthetic Studies of Bacitracin. I. Synthesis of a Protected Intermediate Heptapeptide (5—11)
Authors: Ariyoshi Yasuo , Shiba Tetsuo , Kaneko Takeo
Published: July 2006

A protected heptapeptide, the formyl-l-isoleucyl-ε-benzyloxycarbonyl-l-lysyl-δ-5-tosyl-d-ornithyl-l-isoleucyl-d-phenylalanyl-im-benzyl-l-histidyl-l-aspartic acid α-methyl-β-benzyl ester, was synthesized by the azide method and the carbodiimide method. It is an intermediate peptide for the total synthesis of the antibiotic bacitracin A, the structure of which is still ambiguous at a few points. β-Benzyl benzyloxycarbonyl-l-aspartate was prepared by a novel method similar to that used in the synthesis of γ-benzyl glutamate. The α-methyl-β-benzyl l-aspartate prepared could be useful in the synthesis of branched aspartic acid peptide. Phenomena of dimorphism were observed in crystals of δ-tosyl-d-ornithine and δ-tosyl-d-ornithyl-l-isoleucyl-d-phenylalanine ethyl ester hydrobromide, and two crystal forms of each compound were isolated in pure states.
The Crystal Structure of the 1 : 1 Complex of Naphthalene with 1, 2, 4, 5-Tetracyanobenzene
Authors: Kumakura Shigekazu , Iwasaki Fujiko , Saito Yoshihiko
Published: July 2006

The crystal of the equimolar complex between 1, 2, 4, 5-tetracyanobenzene and naphthalene is monoclinic, with space group C2/m, a=9.39, b=12.66, c=6.87 Å, β=107.2 ° and Z=2. The structure was deduced from the hk0 weighted reciprocal lattice and a packing consideration, and refined by the three-dimensional difference synthesis and the block-diagonal least-squares method. The constituent molecules are approximately planar and overlap each other with an average interplanar spacing of 3.43 Å. They are stacked alternately in infinite columns along the c axis. The structure is disordered, with the naphthalene molecules adopting one of alternative orientations with equal probability. The determined structure is consistent with the electronic spectra of the cyrstal.
The Liquid Phase Oxidation of Acrolein. III. Decompositions of Peracrylic Acid by Catalysts and with Acrolein
Authors: Ohkatsu Yasukazu , Hara Takao , Osa Tetsuo , Misono Akira
Published: July 2006

Peracrylic acid was decomposed by four kinds of catalysts in a benzene solution at 30°C. The order of the catalysts’ effect on the decomposition was: Mn>Co>Fe>Ni; this agreed, except for the reverse order of Co and Mn, with that of the effective catalysts in the oxidation of acrolein (Co>Mn>Fe>Ni). The empirical rate equation,

−d(CH2=CHCOO2H)⁄dt=k(CH2=CHCOO2H)0.58(catalyst)0.56

was obtained from the decomposition by Co(acac)3. On the other hand, from the stationary-state treatment of elementary steps adequate to the reaction and some assumptions, and from the experimental data, the following equation was derived:

−d(CH2=CHCOO2H)⁄dt=1.3×10−1(CH2=CHCOO2H)(Co3+)+9.6×10−3(CH2=CHCOO2H)1⁄2(Co3+)1⁄2

The above two equations have been confirmed as agreeing with each other over the range of reaction conditions used. The interaction of peracrylic acid with acrolein was carried out in the absence of a catalyst under an oxygen or nitrogen atmosphere. In this case, there was formed a complex consisting of both peracrylic acid and acrolein. The complex was mainly decomposed through the ionic mechanism, but in part through the radical mechanism at a higher temperature, namely, through the homolytic cleavage of its peroxy group, followed by the induced decomposition of peracrylic acid. Furthermore, the formation mechanism of acrylic acid in the oxidation of acrolein was discussed in view of the activation energy of the decomposition of peracrylic acid.
Studies on Seven-Membered Heterocyclic Compounds Containing Nitrogen. VIII. Structural Considerations of Pyrazole and Thiazole Compounds Fused with a Hydrazepine Ring
Authors: Yokoo Akira , Morosawa Shiro
Published: July 2006

The alternative structure of III, 2-methyl-4,5,7,8-tetrahydro-6(H)-azepino[5,4-d]thiazole (IV) has been found by a study of the NMR spectrum of the corresponding 6-ethoxycarbonyl derivative (V). The structure of 1-ethoxycarbonyl-3-hydroxymethylene-1-azacycloheptan-one (VIII) has also been ascertained by a study of the NMR spectrum and also by its conversion into the methyl derivative (XI).
The Grignard Reaction of 1,3-Diazaazulene
Authors: Mukai Toshio , Tsuruta Haruki , Momotari Yoshitaka
Published: July 2006

From the point of view of the nucleophilic substitution, the Grignard reaction of 1,3-diazaazulene (I) was investigated using phenyl magnesium bromide and t-butyl magnesium chloride. Substitution occurred at 4- and/or 6-positions of I and 4-phenyl-4H-(II), 4-t-butyl-4H- (VIIIa) and 6-t-butyl-6H-cycloheptaimidazole (VIIIb) were isolated respectively. The NMR and UV spectra of these products were discussed. Of the products, II and VIIIb afforded 4-phenyl-(III) and 6-t-butyl-1, 3-diazaazulene (XI) by dehydrogenation.
Studies of Antibiotics and Related Substances. XXXI. The Synthesis of Kanamycin-6′-phosphate
Authors: Umezawa Sumio , Tatsuta Kuniaki , Tsuchiya Tsutomu , Yamamoto Eiichi
Published: July 2006

The introduction of a phosphate group into the 3-amino-3-deoxy-d-glucose moiety of kanamycin, a useful antibiotic, has been described. Tetra-N-anisylidene kanamycin was treated with diphenyl phosphorochloridate. Hydrolysis of the product followed by hydrogenolysis afforded kanamycin-6′-phosphate in a good yield. An alternative phosphorylation of kanamycin via tetra-N-carbobenzoxykanamycin to hexa-O-acetyl-tetra-N-carbobenzoxy-6′-diphenylphosphoro-kanamycin was described, however, the removal of the all protecting groups except the phosphate group encountered a difficulty.
The Reactions of the Photochemically Produced Electron in Aqueous Hexacyanoferrate(II) Solutions
Authors: Ohno Shin-ichi
Published: July 2006

The reactions of the photochemically-produced electron, e−aq, in an aqueous solution of hexacyanoferrate(II) were studied when H2PO4−, NO3−, H2O2, CO2, [Fe(CN)6]3− and H3BO3 were used as the solute. The relative reaction rates, obtained by competition kinetics, are compared with those calculated using the published data on the absolute rate constants. The agreements are satisfactory in some cases, but not in other cases (e.g., H2PO4−, H2O2 and CO2), for which a possible explanation is given. This explanation includes the postulation of an electrontransfer reaction between the solutes employed; it is shown that information on the efficiency of this electrontransfer reaction may be obtained by using the relative rates obtained both from competition kinetics and from pulse radiolysis.
The Rheological Study of Aqueous Solutions of Polyethylene Glycol at Ultrasonic Frequencies
Authors: Arakawa Kiyoshi , Takenaka Nobuo
Published: July 2006

Ultrasonic investigations of aqueous solutions of polyethylene glycol solutions have been made by means of an ultrasonic pulse technique. Two samples of the polymer have been used, the molecular weights being 4000 and about 6000. The measurements of the sound velocity and of the absorption have been made on 5–30 wt% solutions of the polymers, together with an ethylene glycol-water mixture for the sake of comparison, over the frequency range of 5–45 Mc/sec. The temperature has been varied over the range of 10–70°C. It has been found that the velocity vs. temperature curve for each solution has a peak, and that the peak has a trend to shift to a lower temperature with the increase in the concentration. From the absorption data obtained, it has been found that a characteristic relaxation frequency appears near 40 Mc/sec at room temperatures. The magnitude of the absorption has been found to increase linearly approximately with the increase in the concentration, and to be independent of the molecular weight of the polymers at least in the range studied. From the temperature dependence of the relaxation frequency, the apparent activation energy of the relaxation process has been estimated to be not larger than 1 kcal/mol. It has been concluded from the results that the source of the relaxation process is not the hydrogen bonding between polymer molecules and water, as recently stated by G. G. Hammes et al. (J. Phys. Chem., 70, 1610 (1966)), but some intramolecular process.
The Chemistry of Protactinium. IV. On the Absorption Spectra of Tetravalent Protactinium in Aqueous Solutions
Authors: Mitsuji Toshikazu
Published: July 2006

The liquid zinc amalgam method was developed as a rapid procedure for the reduction of pentavalent protactinium. Several minutes were sufficient for the complete reduction of 4.2×10−4  m pentavalent protactinium in both hydrochloric and sulfuric acid solutions. The stability of tetravalent protactinium in these media was investigated by spectrophotometry. Re-oxidation occurred gradually, even in the absence of atmospheric oxygen, and amounted to 8% in 15 hr. These results may be understood in terms of the slow rate of the (2Pa4++2H+\ightleftarrows2Pa5++H2) reaction. The formation of sulfato complexes of tetravalent protactinium was inferred by spectrophotometry with relation to the similarity of the electronic structure between Pa4+(5f1) and Ce3+(4f1).
The Electronic Structure of Peptide and the Base Components of Nucleic Acids in the Triplet State
Authors: Imamura Akira , Fujita Hiroko , Nagata Chikayoshi
Published: July 2006

The electronic structures of β-naphthol, the base components of nucleic acids, and peptide have been calculated for the ground, singlet-excited, and triplet-excited states by means of the ASMO SCF CI method. The calculated π electron density of β-naphthol agrees well with the experimental data. The π electron density, the dipole moment, and the bond order for the ground, singlet and triplet excited states have been obtained, and the characteristics of the electronic structures for the ground, singlet-excited, and triplet-excited states have been discussed in connection with the chemical behavior of the molecule.