bluuebunny/crossref_metadata_2025 huggingface dataset:
APETALA1andSEPALLATA3interact withSEUSSto mediate transcription repression during flower development
Authors: Sridhar Vaniyambadi V. , Surendrarao Anandkumar , Liu Zhongchi
Published: July 2006

The transcriptional repression of key regulatory genes is crucial for plant and animal development. Previously, we identified and isolated two Arabidopsis transcription co-repressors LEUNIG(LUG) and SEUSS (SEU) that function together in a putative co-repressor complex to prevent ectopic AGAMOUS(AG) transcription in flowers. Because neither LUG nor SEU possesses a recognizable DNA-binding motif, how they are tethered to specific target promoters remains unknown. Using the yeast two-hybrid assay and a co-immunoprecipitation assay, we showed that APETALA1 (AP1)and SEPALLATA3 (SEP3), both MADS box DNA-binding proteins,interacted with SEU. The AP1-SEU protein-protein interaction was supported by synergistic genetic interactions between ap1 and seu mutations. The role of SEU proteins in bridging the interaction between AP1/SEP3 and LUG to repress target gene transcription was further demonstrated in yeast and plant cells, providing important mechanistic insights into co-repressor function in plants. Furthermore, a direct in vivo association of SEU proteins with the AG cis-regulatory element was shown by chromatin immunoprecipitation. Accordingly, a reporter gene driven by the AG cis-element was able to respond to AP1- and SEP3-mediated transcriptional repression in a transient plant cell system when supplied with SEU and LUG. These results suggest that AP1and SEP3 may serve as the DNA-binding partners of SEU/LUG. Our demonstration of the direct physical interaction between SEU and the C-terminal domain of SEP3 and AP1 suggests that AP1 and SEP3 MADS box proteins may interact with positive, as well as negative, regulatory proteins via their C-terminal domains, to either stimulate or repress their regulatory targets.
A role for chromatin remodeling in regulation of CUC gene expression in theArabidopsiscotyledon boundary
Authors: Kwon Chang Seob , Hibara Ken-ichiro , Pfluger Jennifer , Bezhani Staver , Metha Heral , Aida Mitsuhiro , Tasaka Masao , Wagner Doris
Published: July 2006

The CUP-SHAPED COTYLEDON (CUC) genes CUC1, CUC2 and CUC3act redundantly to control cotyledon separation in Arabidopsis. In order to identify novel regulators of this process, we have performed a phenotypical enhancer screen using a null allele of cuc2, cuc2-1. We identified three nonsense alleles of AtBRM, an Arabidopsis SWI/SNF chromatin remodeling ATPase, that result in strong cotyledon fusion in cuc2-1. atbrm also enhances cotyledon fusion in loss-of-function cuc1 and cuc3 mutants, suggesting a general requirement for this ATPase in cotyledon separation. By contrast, a null allele of SPLAYED(SYD), the closest homolog of AtBRM in Arabidopsis, enhances only the loss-of-function cuc1 mutant. By investigating the activities of the CUC promoters in the cotyledon boundary during embryogenesis in sensitized backgrounds, we demonstrate that AtBRM upregulates the transcription of all three CUC genes, whereas SYD upregulates the expression of CUC2. Our results uncover a specific role for both chromatin remodeling ATPases in the formation and/or maintenance of boundary cells during embryogenesis.
Free-flight responses ofDrosophila melanogasterto attractive odors
Authors: Budick Seth A. , Dickinson Michael H.
Published: July 2006

Many motile organisms localize the source of attractive odorants by following plumes upwind. In the case of D. melanogaster, little is known of how individuals alter their flight trajectories after encountering and losing a plume of an attractive odorant. We have characterized the three-dimensional flight behavior of D. melanogaster in a wind tunnel under a variety of odor conditions. In the absence of olfactory cues, hungry flies initiate flight and display anemotactic orientation. Following contact with a narrow ribbon plume of an attractive odor, flies reduce their crosswind velocity while flying faster upwind, resulting in a surge directed toward the odor source. Following loss of odor contact due to plume truncation, flies frequently initiate a stereotyped crosswind casting response, a behavior rarely observed in a continuous odor plume. Similarly, within a homogeneous odor cloud, flies move fast while maintaining an upwind heading. These results indicate both similarities and differences between the behavior of D. melanogaster and the responses of male moths to pheromone plumes,suggesting possible differences in underlying neural mechanisms.
Cardiovascular and haematological responses of Atlantic cod (Gadus morhua) to acute temperature increase
Authors: Gollock M. J. , Currie S. , Petersen L. H. , Gamperl A. K.
Published: July 2006

For fish to survive large acute temperature increases (i.e. >10.0°C)that may bring them close to their critical thermal maximum (CTM), oxygen uptake at the gills and distribution by the cardiovascular system must increase to match tissue oxygen demand. To examine the effects of an acute temperature increase (∼1.7°C h-1 to CTM) on the cardiorespiratory physiology of Atlantic cod, we (1) carried out respirometry on 10.0°C acclimated fish, while simultaneously measuring in vivocardiac parameters using Transonic® probes, and (2) constructed in vitro oxygen binding curves on whole blood from 7.0°C acclimated cod at a range of temperatures. Both cardiac output(Q̇) and heart rate(fh) increased until near the fish's CTM(22.2±0.2°C), and then declined rapidly. Q10 values for Q̇ and fh were 2.48 and 2.12, respectively, and increases in both parameters were tightly correlated with O2 consumption. The haemoglobin (Hb)-oxygen binding curve at 24.0°C showed pronounced downward and rightward shifts compared to 20.0°C and 7.0°C, indicating that both binding capacity and affinity decreased. Further, Hb levels were lower at 24.0°C than at 20.0°C and 7.0°C. This was likely to be due to cell swelling, as electrophoresis of Hb samples did not suggest protein denaturation, and at 24.0°C Hb samples showed peak absorbance at the expected wavelength (540 nm). Our results show that cardiac function is unlikely to limit metabolic rate in Atlantic cod from Newfoundland until close to their CTM, and we suggest that decreased blood oxygen binding capacity may contribute to the plateau in oxygen consumption.
Material properties and biochemical composition of mineralized vertebral cartilage in seven elasmobranch species (Chondrichthyes)
Authors: Porter Marianne E. , Beltrán Jennie L. , Koob Thomas J. , Summers Adam P.
Published: July 2006

Elasmobranchs, particularly sharks, function at speed and size extremes,exerting large forces on their cartilaginous skeletons while swimming. This casts doubt on the generalization that cartilaginous skeletons are mechanically inferior to bony skeletons, a proposition that has never been experimentally verified. We tested mineralized vertebral centra from seven species of elasmobranch fishes: six sharks and one axially undulating electric ray. Species were chosen to represent a variety of morphologies, inferred swimming speeds and ecological niches. We found vertebral cartilage to be as stiff and strong as mammalian trabecular bone. Inferred swimming speed was a good, but not infallible, predictor of stiffness and strength. Collagen content was also a good predictor of material stiffness and strength, although proteoglycan was not. The mineral fraction in vertebral cartilage was similar to that in mammalian trabecular bone and was a significant predictor of material properties.
Metabolic organization and effects of feeding on enzyme activities of the dogfish shark (Squalus acanthias) rectal gland
Authors: Walsh Patrick J. , Kajimura Makiko , Mommsen Thomas P. , Wood Chris M.
Published: July 2006

In order to investigate the metabolic poise of the elasmobranch rectal gland, we conducted two lines of experimentation. First, we examined the effects of feeding on plasma metabolites and enzyme activities from several metabolic pathways in several tissues of the dogfish shark, Squalus acanthias, after starvation and at 6, 20, 30 and 48 h post-feeding. We found a rapid and sustained ten-fold decrease in plasma β-hydroxybutyrate at 6 h and beyond compared with starved dogfish, suggesting an upregulation in the use of this substrate, a decrease in production, or both. Plasma acetoacetate levels remain unchanged, whereas there was a slight and transient decrease in plasma glucose levels at 6 h. Several enzymes showed a large increase in activity post-feeding, including β-hydroxybutyrate dehydrogenase in rectal gland and liver, and in rectal gland, isocitrate dehydrogenase, citrate synthase, lactate dehydrogenase, aspartate amino transferase, alanine amino transferase, glutamine synthetase and Na+/K+ ATPase. Also notable in these enzyme measurements was the overall high level of activity in the rectal gland in general. For example, activity of the Krebs' TCA cycle enzyme citrate synthase (over 30 U g-1) was similar to activities in muscle from other species of highly active fish. Surprisingly, lactate dehydrogenase activity in the gland was also high (over 150 U g-1), suggesting either an ability to produce lactate anaerobically or use lactate as an aerobic fuel. Given these interesting observations, in the second aspect of the study we examined the ability of several metabolic substrates (alone and in combination) to support chloride secretion by the rectal gland. Among the substrates tested at physiological concentrations (glucose, β-hydroxybutyrate, lactate,alanine, acetoacetate, and glutamate), only glucose could consistently maintain a viable preparation. Whereas β-hydroxybutyrate could enhance gland activity when presented in combination with glucose, surprisingly it could not sustain chloride secretion when used as a lone substrate. Our results are discussed in the context of the in vivo role of the gland and mechanisms of possible upregulation of enzyme activities.
Like a `rolling stone': quantitative analysis of the body movement and skeletal dynamics of the sponge Tethya wilhelma
Authors: Nickel Michael
Published: July 2006

Although sponges (Porifera) are basal Metazoa without muscles and a central nervous system, they are able to locomote, which is generally correlated to drastic morphological changes. This behaviour has been known for more almost 150 years, but it is only partly understood. The sponge T. wilhelmadisplays extraordinary movement and rhythmic body contractions, and is thus a valuable model for the investigation of sponge movement. The aims of the present study were to track T. wilhelma quantitatively on natural and artificial substrates, to test for a peristaltic movement mechanism and to check for the influence of morphological changes. T. wilhelmadisplays a unique mode of locomotion among sponges, without reorganizing the whole sponge body. The overall morphology was stable, and skeletal rotation during movement was shown; this is the first time that such movement has been demonstrated in a sponge. The stability of the skeletal superstructure arrangement during movement suggests that only the cortical tissue is involved in movement, with only local tissue rearrangements. The movement track followed a straight direction for long periods, but directions could be altered instantly. It is most likely that environmental conditions play an important roll in induction of movement. In summary, T. wilhelmaresembles the proverbial `rolling stone' that stays at a given location if the conditions are favourable and starts moving when conditions change for the worse.
Effects of different training protocols on Ca2+ handling and oxidative capacity in skeletal muscle of Atlantic salmon (Salmo salarL.)
Authors: Anttila Katja , Mänttäri Satu , Järvilehto Matti
Published: July 2006

The modulation of calcium channel density and oxidative capacity in skeletal muscle after different training protocols were studied in 3-year-old Atlantic salmon smolts. The effect of endurance exercise on dihydropyridine(DHP) and ryanodine (Ry) receptor densities as well as on muscle metabolism were determined by immunoblot and histochemical analysis from swimming muscles of fish subjected to nine different training protocols varying in duration and water current velocity.

In general, exercise training caused a significant increase in the density of both DHP and Ry receptors in both muscle types studied. In red muscle, the most notable increase in DHP and Ry receptor expression was observed in muscle sections from fish swimming against intermediate current velocity for a 2-week period (182.3±16.3%, 234.6±30.3%, respectively). In white muscle, the expression of DHP and Ry receptors was most upregulated after a 6-week swimming period also at intermediate water current velocity(270.4±23.9%, 114.4±15.3%, respectively). As with the activity of enzymes involved in muscle energy supply, endurance exercise resulted in a significant increase in succinate dehydrogenase (SDH) activity, but a significant decrease in phosphorylase activity.

We conclude that the expression of both DHP and Ry receptors was upregulated in the swimming muscles of salmon as a consequence of exercise training. This, along with the increased oxidative enzyme activity, provides benefits to the contraction efficiency of fish muscles while swimming. However, it was also observed that optimal oxidative swimming capacity is achieved only with a proper exercise program, since the most relevant changes in DHP and Ry receptor expression, as well as in oxidative capacity, were seen in the group training with the intermediate swimming velocity.
Sound production mechanism in carapid fish: first example with a slow sonic muscle
Authors: Parmentier Eric , Lagardère Jean-Paul , Braquegnier Jean-Baptiste , Vandewalle Pierre , Fine Michael L.
Published: July 2006

Fish sonic swimbladder muscles are the fastest muscles in vertebrates and have fibers with numerous biochemical and structural adaptations for speed. Carapid fishes produce sounds with a complex swimbladder mechanism, including skeletal components and extrinsic sonic muscle fibers with an exceptional helical myofibrillar structure. To study this system we stimulated the sonic muscles, described their insertion and action and generated sounds by slowly pulling the sonic muscles. We find the sonic muscles contract slowly, pulling the anterior bladder and thereby stretching a thin fenestra. Sound is generated when the tension trips a release system that causes the fenestra to snap back to its resting position. The sound frequency does not correspond to the calculated resonant frequency of the bladder, and we hypothesize that it is determined by the snapping fenestra interacting with an overlying bony swimbladder plate. To our knowledge this tension release mechanism is unique in animal sound generation.
The ESR Study of the Ion Pair Complexes of m-Iodonitrobenzene with Alkali and Alkaline Earth Metals
Authors: Nakamura Kazuo
Published: July 2006

The ESR spectra of the ion-pair complexes of the m-iodonitrobenzene anion with alkali and alkaline earth cations were measured. Cation-induced variations in the nitrogen and proton splitting constants were found. When the observed alkali metal splittings were related to the back-transferred charge, ρ, on the ns-shell of each metal, ρ increased in the sequence: Li<Na<K<Rb<Cs at 20°C. The solvent and the temperature effects on alkali-metal splitting varied with the alkali metal. The Cs and Rb splitting constants increased in the sequence: DME<THF<THP solutions, and were independent of the temperature. The Na and Li splitting constants decreased in the above sequence of solvents. With a lowering of the temperature, the Na splitting constant decreased while the Li splitting constant increased. The K splitting constant was independent of both the temperature and the solvent. These results were found in the ion pairs of other halogeno-nitrobenzenes, also.
A Classification of Polymerizations from a Kinetic Point of View
Authors: Kagiya Tsutomu , Izu Masatsugu , Fukui Kenichi
Published: July 2006

Polymerizations were classified from a kinetic point of view. The polymerizations were divided into those with a rapid initiation and those with a slow initiation, according to the magnitude of the initiation rate in relation to the propagation rate. Both of these groups were then divided into stationary and non-stationary polymerizations according to the change in the number of moles of the propagating species with the reaction time. The next sub-classification, into chain and successive polymerizations, was made by estimating the change, with the reaction time, in the number-average degree of the polymerization of the polymer formed. Each proposed class was shown to possess a characteristic kinetic feature. Several examples of each class were collected.
Studies of Diarylalkanes. IV. The Cleavage of Diphenylmethanes under the Influence of Aluminum Chloride in the Binary Mixture of Benzene with Chlorobenzene
Authors: Tsuge Otohiko , Tashiro Masashi
Published: July 2006

The reactions of DPM and its chloro derivatives with aluminum chloride in a mixture of benzene and chlorobenzene have been studied in order to obtain clearer information concerning the bond cleavage of the diarylmethanes. The constants or the activation energy of the cleavage reaction have been determined, and it has found that, in such reactions, a first-order dependence on the aromatic substrate exists; an equilibrium relationship consisting of four systems has been an equilibrium relationship consisting of four systems has been established among the products. The isomer distribution of the Cl-DPM which was formed by the cleavage of DPM or 4-Cl-DPM exhibited a marked variation with the reaction time. These results show that the cleavage reaction is closely connected with Friedel-Crafts benzylation.
An Experimental Study of the Vaporization of Chlorine Compounds from Basaltic Lavas during the Cooling Process. I
Authors: Iwasaki Bunji , Katsura Takashi
Published: July 2006

An attempt was made to make clear the manner of the vaporization of chlorine compounds from basaltic rocks at a series of temperatures ranging from 1000 to 1300°C, in atmospheres of air and of a mixed gas (CO2–H2), and on cooling from 1200 to 800°C in air, neglecting the effect of water vapor. The vaporization of chlorine compounds was found to take place from the surface of a melt and through the interstices of rock grains. When crystals began to separate from the melt, they suddently prevented the vaporization. From the results of cooling experiments on the basaltic melt, it was concluded that the chlorine compounds in the liquid basaltic lava extruded at approximately 1200°C are continously vaporized until the liquid lava is covered with thin films including crystals and glassy materials. The temperature at which the vaporization of chlorine compounds ceases is 1100°C at the highest.
Reaction of Perchloro-(3, 4-dimethylenecyclobutene) with Molecular Oxygen
Authors: Kusuda Kousuke , Mano Koichi , Fujino Akira , Sakan Takeo
Published: July 2006

The reaction of perchloro-(3, 4-dimethylenecyclobutene) (I) with molecular oxygen in the solutions of carbon tetrachloride, benzene and ether was investigated. The identified products were phosgene, perchloro-(dimethylenesuccinic) acid (IIa), its dichloride, its anhydride, perchloro-(2, 3-dimethylenecyclobutanone) (IV) and 2, 2, 3′, 3′, 4-pentachloro-3-methyleneglutaric acid (VIII) in carbon tetrachloride. In benzene the products were the same as in carbon tetrachloride except VIII. Phosgene, oxalic acid, IIa and perchloro-(3-cyclobutene)-1, 2-dicarboxylic acid were obtained in ether. A radical chain mechanism is suggested for the degradations in the former two solvents on the basis of the similar reaction of I with oxygen in tetrachloro-ethylene yielding phosgene, IV, VIII and trichloroacetyl chloride. A possibility that I could be a chlorine radical source for the chain initiation by forming an unstable adduct with oxygen in the solution is also discussed.
Reactions of Alkylantimony Compounds with Titanium Chlorides
Authors: Takashi Yûkichi
Published: July 2006

The reactions of various alkylantimony compounds with titanium chlorides have been investigated. Tetraethylstibonium chloride was found to react with titanium tetrachloride to give the complex salts [SbEt4]2TiCl6 (I), [SbEt4]TiCl5 (II) and [SbEt4]Ti2Cl9 (III), and with titanium trichloride to give the complex salts [SbEt4]2TiCl5 (VI) and [SbEt4]TiCl4 (V). Titanium dichloride was oxidized by tetraethylstibonium chloride to form the complex salts of tervalent titanium, IV and V. Triethylantimony dichloride made addition with titanium tetrachloride and afforded two or more ionic complexes, SbEt3Cl2·TiCl4 and (SbEt3Cl2)m(TiCl4)n. Titanium dichloride was oxidized by triethylantimony dichloride to give a complex of tervalent titanium, SbEt3·nTiCl3. Triethylstibine reduced titanium tetrachloride and formed an adduct of tervalent titanium, SbEt3Cl2·2TiCl3, when an excess of titanium tetrachloride was allowed to react. An excess of triethylstibine gave rise to complicated reactions with titanium tetrachloride, and formed TiCl3·mSbEt3Cl2·nSbt3 complexes.
Studies on the Isomerization Esterification of Crotonyl Chloride to the Vinylacetic Acid Ester. II. The Effects of the Amine, the Alcohol, the Solvent, and the Reaction Temperature
Authors: Ozeki Toshitsugu , Kusaka Masakatsu
Published: July 2006

The effects of the amine, the alcohol, the solvent, and the reaction temperature on the isomerization esterification of crotonyl chloride to the vinylacetic acid ester were investigated. Amines can be divided into three groups. The first group includes the amines with pka-values as high as 10; they give the isomerized product, ethyl vinylacetate (IEt), in a ca. 90% yield. The second includes the amines with pKa-values lower than 7.2; they give the normal product, ethyl trans-crotonsite (IIIEt). The third includes the remaining amines with intermediate pKa-values; they give various amounts of the two products. Ethyl cis-crotonate (IIEt) is always formed in only a small quantity. Alcohols favored the product ratio of IEt in the order:

MeOH<EtOH<i-BuOH<i-PrOH<t-BuOH.

Various aliphatic and aromatic solvents gave almost identical product ratios, regardless of their polarities. Below room temperature, the formation of IEt was predominant (ca. 95—97%), but above that temperature IIEt and IIIEt increased. It was understood that the steric factors of amine and alcohol influenced the extent of the double-bond shift and that the reaction proceeded via the ketene intermediate. The course of the reaction has been discussed.
Spectroscopic Studies on 2-Pyrazolin-5-one Dyes
Authors: Yasuda Heinosuke
Published: July 2006

The spectra of forty-five 2-pyrazolin-5-one dyes in the ultraviolet and visible regions are discussed on the basis of their hydrazone-keto structures. In particular, the effects of sterically-sensitive ortho-substitutions in the 1- and 4-positions on the pyrazolinone ring are investigated. The bathochromic effects on the visible absorption band of pyrazolinone dyes are caused by electron-attracting substituents in the 3-position, not by 1- and 4-substituents.
The Kinetics of the Vapor-Phase Ammoxidation of Xylene Isomers over a Vanadium Catalyst
Authors: Ito Masatomo , Sano Ken-ichi
Published: July 2006

The kinetics of the vapor-phase ammoxidation of xylene isomers over a vanadium oxide catalyst was studied in a flow system. The reaction-rate data obtained for each xylene were then correlated with the rate equations based upon the Langmuir-Hinshelwood mechanism; this correlation suggested that each xylene reacted by a parallel consecutive reaction scheme in which tolunitrile was involved as an intermediate. The order of the relative ease of reaction was: para>meta\fallingdotseqortho. The ratio of the specific rate constant of xylenes, kx, to that of tolunitriles, kM, was 6 for meta and para isomers and 4 for the ortho isomer at 400°C; this ratio decreased with an increase in the reaction temperature. The order of relative ratios for the direct formation of dicyanobenzenes from xylenes was ortho>meta>para, while that for the direct formation of carbon oxides and hydrogen cyanide was ortho\fallingdotseqmeta>para. The ratio of the specific rate constant for the formation of dicyanobenzenes from tolunitriles, k2, to kM decreased with an increase in the ratio of kx to kM. These results seem to result from the adsorptivities of xylenes and tolunitriles on the catalyst surface.
Hydrogen Bonding between Phenols and Carbon Disulphide
Authors: Sannigrahi A B , Chandra A K
Published: July 2006

The effect of hydrogen bonding on the near ultraviolet absorption spectra of some phenols was studied with carbon disulfide as a base. The results show that the π→π* bands of phenols move toward longer wavelength and the n→π* band of carbon disulphide moves toward shorter wavelength. From the optical density measurements in the wavelength regions where both the bands occur the stability constants of the hydrogen bonded complexes were measured. From the result it was concluded that proton donating power of the phenols increases in the order p-cresol<phenol<β-naphthol<α-naphthol which is exactly the relative order of their acidities. These results also support the electrostatic theory of hydrogen bonding.
Effect of Electric Fields on Gamma Radiolysis of Methanol Vapor
Authors: Ohmae Tadayuki , Sakurai Hiroshi
Published: July 2006

Electric fields were applied during the irradiation of methanol vapor up to voltages necessary to cause secondary ionization. The yields per ion pair of 3.00±0.02, 0.39±0.02, and 0.120±0.003 were estimated for hydrogen, carbon monoxide, and methane respectively by relating the product yields to the saturation ion current measured during the irradiation. The hydrogen yields decreased in the saturation current region, while the carbon monoxide and the methane yields remained nearly constant. The reduction of hydrogen yield may be ascribed to a suppression of dissociative electron-capture process CH3OH+e→CH3O−+H by a fast electronabsorption to the anode. The contribution of molecular or hot hydrogen atom process to the formation of hydrogen was found to increase with an increase of the electric field strength.
The Crystal Structure of Benzaldehyde-Potassium Bisulfite Addition Product (Potassium α-Hydroxybenzylsulfonate)
Authors: Kuroda Toshimasa , Ashida Tamaichi , Sasada Yoshio , Kakudo Masao
Published: July 2006

The addition compound of benzaldehyde and potassium bisulfite crystallizes in the monoclinic space group P21⁄c, with four formula units per unit cell with the dimensions: a=16.37, b=6.07, c=9.12 Å and β=103.4°. The structure was determined by the heavy atom method, and the structural parameters were refined by least-squares method with a block-diagonal approximation. The analysis showed that the addition product is potassium α-hydroxybenzylsulfonate, C6H5CH(OH)SO3−·K+. Three S-O bond distances range from 1.43 to 1.46 Å; the average of three O-S-O bond angle is 112.1°, while that of three O-S-Cα’s is 106.7°. The bond distance of S-Cα, 1.831 Å, is significantly longer than those in other sulfonates so far reported. The potassium ion is surrounded by nine oxygen atoms; the K-O distances being from 2.73 to 3.27 Å.
Mono-, Di- and Tri-ethanolamine Derivatives of Samarium
Authors: Sankhla B S , Kapoor R N
Published: July 2006

Reactions of samarium isopropoxide with mono-, di- and tri-ethanolamines have been studied in presence of benzene. The reaction between samarium isopropoxide and monoethanolamine in different molar ratios gave mono-, di- and tri- derivatives. Compound Sm(dieth. am)(OPri) is formed when samarium isopropoxide (1 mol) reacted with diethanolamine (1 mol), whereas the reaction in the molar ratio of 2 : 3 yielded Sm2(dieth. am)3. All the three moles of isopropanol were liberated when an equimolecular quantities of samarium isopropoxide and triethanolamine were allowed to react with the isolation of samarium triethanolaminate. The only soluble compounds being Sm(monoeth.am) (OPri)2 and its corresponding tertiary butanol derivative, Sm(moneth. am)(OBut)2. Attempts to distil some of these compounds were unsuccessful, as these decompose on being heated under reduced pressure.
Cobalt(II) Complexes of Schiff Bases Derived from 3-Methoxysalicylaldehyde and Amines
Authors: Yoshida Emiko , Yamada Shoichiro
Published: July 2006

Bis(N-substituted-3-methoxysalicylideneiminato)cobalt(II) complexes, including several new compounds, have been prepared, and their configurations examined. It has been concluded that these cobalt(II) compounds take a tetrahedral configuration of a high-spin type in nondonor solvents and in the solid state. For R=n-alkyl and monosubstituted phenyl, these complexes in pyridine take an octahedral configuration, with two pyridine molecules bound to the cobalt(II) ion. However, bis(N-2′, 6′-dimethylphenyl- and bis(N-2′, 6′-diethylphenyl-3-methoxysalicylideneiminato) complexes take a hexa-coordinate, though considerably distorted, configuration in pyridine. This behaviour is different from that of the corresponding salicylideneiminato-complexes of cobalt(II). The results of the present work are compared with the findings on the corresponding salicylideneiminato-complexes.
The Kinetics of the Acid-catalyzed Etherification of the Tautomers of p-Nitrosophenol and p-Benzoquinoneoxime with Ethanol
Authors: Furuya Yoshiaki , Morikawa Daiyoshi , Itoho Kazuo
Published: July 2006

The rates of the acid-catalyzed reversible etherification reaction of the allelotrope of p-nitrosophenol and p-benzoquinoneoxime with ethanol to form p-nitrosophenetole have been measured by ultraviolet spectrophotometry. The rates of the forward reaction have been found to be the sum of the rate of the second-order with ethanol and the allelotrope and a small portion of the first-order with the allelotrope. The plot of the logarithm of the forward rate constant vs. the acidity function gave a straight line with a slope of −0.93. We have postulated a probable mechanism involving the rate-determining attack of protonated ethanol on the carbonyl O-atom of p-benzoquinoneoxime and a small portion of the rate-determining protonation to the allelotrope, thus forming protonated p-nitrosophenol, followed by a rapid attack on the hydroxyl O-atom of ethanol. The energy of the activation of the forward reaction was 16.3 kcal/mol.
The Ring-opening Polymerization of Cyclic Aminophosphinites
Authors: Fujisawa Tamotsu , Yokota Yukio , Mukaiyama Teruaki
Published: July 2006

A further study of 1, 3-addition-type ring-opening polymerization has been attempted by using cyclic N-phenyl- and N-methylethyleneamino phenylphosphinites as monomers, each of those has a nitrogen atom in place of one of the two oxygen atoms in the ring structure of a cyclic phosphonite. They were prepared from phenylphosphonous dichloride and N-phenyl-and N-methylaminoethanols. The ring-opening 1, 3-addition reaction of the N-phenyl derivative with benzyl bromide, as a model experiment for the polymerization, has been found to proceed smoothly, giving the desired adduct, which in turn gave benzylphenylphosphinic acid and N,N′-diphenylpiperadine on hydrolysis. These cyclic aminophosphinites were then polymerized to give the expected poly(aminophosphine oxide) s in the presence of Arbusov reaction-type reagents or in the absence of a catalyst at elevated temperatures.
The Modification of Polypropylene by the Blending of a Polymeric Fine Powder with Crosslinkage
Authors: Mizutani Yukio
Published: July 2006

In order to improve the properties of polypropylene (PP), the modification of PP by the blending of a polymeric fine powder with crosslinkage (PFPC) was investigated. PFPC, prepared by the radical polymerization of vinyl monomers and divinyl benzene (DVB), was blended into PP, and the properties of the polymer composite were studied. The dyeability of the composite was much improved. PFPG with a reactive functional group was especially available, because the dye could be fixed perfectly in the substrate. On the other hand, it was found that the addition of PFPG did not much cause the following properties to deteriorate: the transparency, the thermal stability, the melt index, and the pressure coefficient of the polymer efflux rate at 230°C and in the applied pressure range of 20—40 kg/cm2.
The Square-Wave Polarographic Determination of Free Sulfur in Liquefied Petroleum Gases
Authors: Kashiki Masayuki , Oshima Shozo
Published: July 2006

A method has been developed for the polarographic determination of the free sulfur present in liquefied petroleum gases in concentrations as low as 0.01 ppm. Samples of liquefied petroleum gases are collected in a specially-fitted pressure glass bottle. After the volatilization of the sample, the free sulfur remaining in the sample container is dissolved in a methanol-methyl iodide-glacial acetic acid-sodium acetate solvent, and the resulting solution is electrolyzed polarographically. The effect of the change in solvent and in supporting electrolyte concentration, dissolved oxygen and temperature are discussed. It is found that the concentrations of 90 vol% methanol, 2 vol% glacial acetic acid, 8 vol% methyl iodide, and 1.5 m sodium acetate are necessary to obtain satisfactory analytical results. The polarographic wave of free sulfur consisted of two waves; the peak potential of the first wave was −0.57 V vs. SCE, while that of the second wave was −0.87 V vs. SCE. The limit of determination was governed by the solubility of the naphtha in the base solution.
Aminobutadienes. IV. Addition Reactions to 1-Phthalimido- and 2-Phthalimido-1,3-butadienes
Authors: Terada Akira , Murata Kenichi
Published: July 2006

1-Phthalimido-1,3-butadiene (I) and 2-phthalimido-1,3-butadiene (II) were chosen for study as typical imidobutadienes in order to clarify the role of such imido groups in determining the orientation of the addition reactions, and also the addition modes in their own polymerizations. The addition reactions of either I or II with bromine, hydrogen chloride, acrolein, acrylic acid and its methyl ester, maleic anhydride, and p-benzoquinone were shown to give the corresponding adducts. However, with crotonaldehyde, I and II each gave only the polymer. The ozonolysis studies have shown that all of the dibromides and monochlorides were 1,4-adducts, 1-chloro-1-phthalimido-2-butene (V) and 1-chloro-3-phthalimido-2-butene (XIII) respectively. No further hydrochlorination of V and XIII took place, even under more vigorous conditions. The major products obtained by the additions of acrolein, acrylic acid, and its methyl ester to I and II were shown to be 1-phthalimido-6-substituted-2-cyclohexene or 1-phthalimido-4-substituted-1-cyclohexene respectively.
Studies of Peptide Antibiotics. X. Syntheses of Cyclosemigramicidin S and Gramicidin S
Authors: Waki Michinori , Izumiya Nobuo
Published: July 2006

The possibility of the occurrence of benzyloxycarbonyl-substituted cyclosemigramicidin S in the course of the cyclization reaction of a linear-pentapeptide-active ester with pyridine was investigated. It was indicated that the crude product of the cyclization of the linear-active ester was composed of two components. The protected gramicidin S, a less soluble material, was easily isolated by fractional crystallization, while the protected cyclosemigramicidin S, a more soluble material, was isolated by a column chromatography of Sephadex LH-20. The hydrogenolyses of these products in the presence of hydrogen chloride afforded the crystalline hydrochlorides of gramicidin S and cyclosemigramicidin S. The cyclic decapeptide was as active as the natural gramicidin S, however, cyclosemigramicidin S showed no activity in response to any of the microorganisms tested.
Studies of Poly-β-benzyl-l-aspartate Helix. III. Infrared Spectra of Copolymers of β-Benzyl-l-aspartate with β-p-Methyl, Chloro, Cyano, or Nitrobenzyl-l-aspartate in a Chloroform Solution
Authors: Hashimoto Masahisa , Arakawa Satoshi
Published: July 2006

Infrared studies of the copolymers in a chloroform solution have revealed that, in each series of copolymers, the transition from the left- to the right-handed α-helix simultaneously brings about sharp changes in the characteristic amide frequencies. The frequencies of the NH-stretching, amide I, and amide II bands of the copolymers in the left-handed α-helix are higher by ca. 13 cm−1, ca. 10 cm−1, and ca. 5 cm−1 respectively than those in the right-handed α-helix. The amide bands of the copolymers in the right-handed form lie in the normal frequency ranges as established for α-helical polypeptides. On the contrary, the amide frequencies of poly-β-benzyl-l-aspartate or the copolymers in the left-handed form are anomalous. The anomalous amide frequencies of the lefthanded helix are to be ascribed to the reversal in the helical sense, but not to the particular aspartate group, since the copolyaspartate esters in the right-handed helix exhibit normal amide frequencies. The transition in the helical sense is reflected also in the C=O stretching bands of the side-chain ester groups.
Studies on the Membrane Permeability of Silver and Cadmium Ferro- and Ferricyanides
Authors: Malik Wahid U , Arif Hasan , Siddiqi Fasih A
Published: July 2006

The permeability and membrane potential of various electrolytes, through parchment supported silver and cadmium ferro- and ferricyanide membranes was investigated. The order of permeability was found to be:

Cl−>NO3−>SO4−2>FeCy6−3>FeCy6−4

while membrane potential was of the reverese order. The magnitude of permeability and potential values, decreases or increases respectively, with potassium ferro- or ferricyanide treated membranes. The relation y=ax1⁄n where x and y represents permeability and potential respectively, and a and n are constants, proposed earlier has been found to be valid for these membranes also. The energy of activation for the diffusion process for various electrolytes was found to lie between 4 to 10 kcal/mol. The potential values determined at varying concentrations of electrolytes, showed that the values increase with dilution. The electronegative character of the membranes, have got a profound influence on the movement of the anions. When the concentration of the electrolyte within the pores are higher, the repulsion of the fixed charges are reduced by screening, that is, at higher concentrations the selectivity of the membrane is decreased to an appreciable extent, resulting thereby in a marked decrease in membrane potential and increase in the permeability values.
The Photochemistry of Aqueous Hexacyanoferrate(II) Solutions. I. Photo-aquation Reaction at 3660 Å
Authors: Ohno Shin-ichi
Published: July 2006

The photochemistry of hexacyanoferrate(II) ions in aqueous solutions was studied at 3660 Å in the presence and in the absence of nitrous oxide as an electron scavenger. Only a photo-aquation reaction yielding aquopentacyanoferrate(II) and cyanide ions was observed to occur as the primary process. The formation of aquopentacyanoferrate(II) ions, determined spectrophotometrically after a reaction with sodium azide, was studied as a function of the irradiation time over a wide pH range (0.5 to 13). In neutral or alkaline solutions the amount of aquopentacyanoferrate(II) ions measured was small, because of an efficient thermal back reaction. The initial quantum yield depended on the pH; for example, the yield 0.52 at pH 0.65 and 0.89 at pH 4.0 for 0.01 m solutions at 25 °C. The yield decreased with an increase in the hexacyanoferrate(II) concentration.
Racemization Catalyst for Amino Acids. II. Racemization with Aurintricarbonic Acid
Authors: Hirota Kazuhiro , Miyamoto Kunihiko , Izumi Yoshiharu
Published: July 2006

The catalytic racemization of amino acids with aurintricarboxylic acid was examined in the presence of cupric ion. The tests were conducted at various pH values to study the optimum pH for the racemization. Moreover the racemizations with aurintricarboxylic acid and with o-cresolphthalein were compared and the results are briefly discussed with regard to the relationship between the structural features and the activities of these catalysts.
Cobalt(II) Complexes of β-Ketoamines Derived from β-Diketones and Aromatic Amines
Authors: Yamada Shoichiro , Yoshida Emiko
Published: July 2006

Many compounds of the Co(Aca.R)2 and the Co(Bza.R)2 type have been synthesized, in order to examine the stereochemistry of bis(β-ketoaminato) cobalt(II) complexes (bis(acetylacetone and bis(benzoylacetone-aminato)cobalt(II) complexes are abbreviated as Co(Aca.R)2 and Co(Bza.R)2, respectively, R being an aryl group attached to the nitrogen atom.) and compare it with that of bis (salicylideneiminato) cobalt (II) complexes. The configuration of these cobalt (I I) complexes in non-donor solvents is tetrahedral, but the complexes in pyridine take a tetrahedral, a penta-coordinate or an octahedral configuration, depending upon the ligand. The complexes of the Co(Bza.R)2 type in pyridine take an octahedral configuration, except for Co(Bza.2, 6-X2C6H3)2, where X denotes CH3 and C2H5. On the contrary, Co(Aca.CH3C6H4)2, Co(Aca.2, 6-(CH3)2C6H3)2 and Co(Aca.α-naphthyl)2 in pyridine retain a tetrahedral configuration, while the complexes, such as Co(Aca.C6H5)2 and Go(Aca.ClC6H4)2, take an octahedral configuration with two pyridine molecules bound to the cobalt(II) ion.
Spectrophotometric Study of the Solution Equilibria between Eriochrom Black T and Zinc(II)-Nitrilotriacetate or Copper(II)-Cyclohexanediaminetetraacetate
Authors: Kodama Mutsuo , Ebine Hide
Published: July 2006

The solution equilibria between Eriochrom Black T (BT) and the zinc(II)-NTA or copper(II)-CyDTA chelate were studied spectrophotometrically, and the stability constants and the compositions of 1-to-1 chelates of BT with these metal ions were determined. Under the experimental conditions employed, irrespective of pH, copper(II) forms only a normal chelate, CuD−, with BT, the stability constant of which is 1021.98(μ=0.10). Zinc (II), however, forms a normal chelate, ZnD−, at pH values lower than 9.00 and a mixed chelate, ZnDX4−, with BT and NTA at pH values higher than 9.00. The stability constant for ZnD− was determined to be 1012.76 (μ=0.10) at pH 8.50, in good agreement with the value reported by Schwarzenbach, and that for ZnDX4−, 1015.38 (μ=0.10).
Studies of the Mixed Amino-acid Complexes of Cobalt(III). II. A Complete Series of [Co(ox)x(gly)y(en)z] Complexes
Authors: Matsuoka Nobuko , Hidaka Jinsai , Shimura Yoichi
Published: July 2006

Five new complexes, C1-cis(O)[Co(gly)2(en)]Br·3H2O, C2-cis(O)-[Co(gly)2(en)]Br·H2O, trans(N)-K[Co(ox)(gly)2], C1-cis(N)- and C2-cis(N)-Na[Co(ox)(gly)2], have been synthesized. The geometrical isomers of both the [Co(gly)2(en)]+ and the [Co(ox)(gly)2]− complex have been separated by ion-exchange column chromatography. The geometrical structures have been determined on the basis of the visible absorption spectra and of the NMR spectra, and from a consideration of the reaction processes of derivation. The visible and near-ultraviolet absorption spectra of a complete series of the sixteen complexes of the [Co(ox)x(gly)y(en)z] type, have been measured and discussed.
The Stereochemistry of Hydrogenation and Hydrogenolysis. VIII. The Stereochemistry of the Reduction of 2-Acetoxy-1-tetralone and 3-Acetoxy-4-chromanone
Authors: Hanaya Kaoru
Published: July 2006

2-Acetoxy-1-tetralone (VI) and 3-acetoxy-4-chromanone (VII) were reduced with a metal hydride complex and by catalytic hydrogenation; the main products of the reduction were found, to be cis-forms. These results indicate that, in the catalytic hydrogenation, the acetoxyl groups at the C-2 position of VI and at the C-3 position of VII hinder these carbonyl compounds from being adsorbed on the catalyst; also, in the reduction with metal hydride complex, the acetoxyl groups exert a steric hindrance upon the approach of the hydride ion to the carbonyl carbon atom.
Kinetic Studies of Bimolecular Nucleophilic Substitution. I. Rates of SN2 Reactions of Phenacyl Bromide with Sodium Phenoxides and Sodium Carboxylates in 50% Aqueous Acetone
Authors: Okamoto Kunio , Kushiro Hajime , Nitta Issei , Shingu Haruo
Published: July 2006

The rates of the bimolecular nucleophilic substitution (SN2 reactions) of phenacyl bromide with sodium para-substituted phenoxides, sodium para-substituted benzoates, and sodium aliphatic carboxylates have been measured in 50% aqueous acetone at 10–70°C. Linear free-energy relationships between the nucleophilic reactivities and basicites (expressed in terms of the pKa’s of the conjugate acids) have been observed in the reactions of para-substituted aromatic nucleophiles, whereas no linear relationships have been seen in the reactions of aliphatic carboxylates except in the cases of sodium acetate, sodium formate, and sodium monochloracetate. An equation, logk2=αpKa+const., has been applied to these reaction series and to the 30 literally-known series of SN2 reactions. The correlation coefficients have then been calculated as a measure of the precision of these linear relationships. Hammett’s ρ values for the reactions of para-substituted aromatic nucleophiles have also been calculated, and the several factors which affect the linear relationships have been discussed.
The Reaction of Nitrosyl Chloride and of Nitryl Chloride with 2-Cholestene
Authors: Terada Akira , Hassner Alfred
Published: July 2006

In connection with our studies on introduction of nitrogen functions into steroids we investigated the addition of nitrosyl chloride and of nitryl chloride to 2-chlestene. Addition of nitrosyl chloride to 2-cholestene followed by dehydrohalogenation with pyridine leads to 2-nitro-2-cholestene as the only isolable product. The formation of nitro addition products is not attributable to the reaction of the olefin with nitryl chloride since the latter reacts with 2-cholestene to give mainly 2β, 3α-dichlorocholestane and 3α-chloro-2β-cholestanyl nitrate.
The Aconite Alkaloids. XXXVII. Anhydro-diacetyldelcosine (Anhydrodiacetyllucaconine) and Its Novel Hydrogenation
Authors: Amiya Takashi , Shima Takeo
Published: July 2006

Delcosine (lucaconine) and its derivatives have all been shown to lose one mole of water, upon treatment with acetyl chloride, thus giving an anhydro compound. On the basis of the observation of the infrared spectra of anhydro-diacetyldelcosine, anhydro-oxodelcosine, and anhydro-1, 10-didehydro-oxodelcosine, it may be concluded that, in each compound, dehydration takes place between two tertiary hydroxyl groups, with a ketone carbonyl group being formed. Based on a tentative structure for delcosine proposed by Marion and his co-workers, structures for anhydro-diacetyldelcosine and anhydro-oxdelcosine are proposed. On hydrogenation over platinum in acetic acid, anhydro-diacetyldelcosine yielded anhydro-dihydro-diacetyl-delcosine. Anhydro-oxodelcosine was inert under these reduction conditions. On the basis of these experimental results, a possible mechanism of this novel hydrogenation is proposed. The ultraviolet spectrum of anhydro-diacetyldelcosine, with a new type of chromophore, is also shown.
Reactions of Aldehyde Caused by Tris(trimethylsiloxy)aluminum
Authors: Saegusa Takeo , Kitagawa Sadao , Ueshima Takashi
Published: July 2006

Reactions of n-butyraldehyde caused by tris(trimethylsiloxy)aluminum were examined and compared with those caused by aluminum t-butoxide. In the Tishchenko reaction of aldehyde caused by aluminum t-butoxide, the t-butoxy group was first transferred from aluminum to the carbonyl group of n-butyraldehyde to produce t-butyl n-butyrate. On the other hand, we observed no formation of trimethylsilyl n-butyrate by the transfer of the trimethylsiloxy group to n-butyraldehyde. However, esters of the n-butyric acid of n-butanol and the glycol derived from the aldol of n-butyraldehyde were found in the system with tris(trimethylsiloxy)aluminum: their formation was ascribed to the aluminum alkoxide species which was first formed between tris(trimethylsiloxy)aluminum and the aldol of n-butyraldehyde. The above assumption has been supported by the finding that aluminum t-butoxide caused the Tishchenko reaction of benzaldehyde, producing benzyl benzoate almost quantitatively, whereas tris(trimethylsiloxy)aluminum did not cause any change because aldol condensation was impossible for benzaldehyde.