Higher Carboxylic Acids Research Articles

Extraction Chromatography of lndium(III) on Silica Gel impregnated with High Molecular Weight Carboxylic Acid and its Analytical Applications

Extraction Chromatography of lndium(III) on Silica Gel impregnated with High Molecular Weight Carboxylic Acid and its Analytical Applications

Photochemical formation of silver metal films from silver salt of natural high molecular carboxylic acid

Thin films of silver salt of alginic acid, a typical high molecular carboxylic acid in nature, were photolyzed by 253.7 nm light. On irradiating with a 15-W sterilization lamp in air at relative humidity of more than 70%, the silver alginate films first became yellow-brown colored due to formation of photolytic colloidal silver particles. When irradiation was continued, the irradiated surface of the films finally changed into clear silver mirror. The morphology of these films was observed by means of a high-resolution scanning electron microscope. Colloidal silver particles (10–50 nm diam) formed by a short-time irradiation were sparsely distributed at the film surface. As a result of prolonged irradiation for ∼180 min, film surface was covered with aggregated colloidal silver. The x-ray diffraction study of the irradiated films revealed sharp diffraction lines, indicating that the colloidal silver was in a highly crystalline state. A preliminary observation of a microtomed cross section of the film showed that colloidal silver particles had a tendency to precipitate at the irradiated side of the film. These observations were consistent with more than a 108 -fold decrease of the sheet resistance and change in transmittance spectra of the films caused by photolysis. It has been proposed that silver atoms from the silver alginate migrate and coalesce to yield the colloidal silver. The colloidal silver particles further diffuse in the film and aggregate themselves at the irradiated surface, giving rise to silver metal films.

Reversed-phase Extraction Chromatography of Gallium(III) on Silica Gel impregnated with High Molecular Weight Carboxylic Acid

Reversed-phase Extraction Chromatography of Gallium(III) on Silica Gel impregnated with High Molecular Weight Carboxylic Acid

Reversed Phase Extraction Chromatographic Studies of lron(III) on Silica Gel impregnated with High Molecular Weight Carboxylic Acid and its Analytical Applications

Reversed Phase Extraction Chromatographic Studies of lron(III) on Silica Gel impregnated with High Molecular Weight Carboxylic Acid and its Analytical Applications

High carboxylic acid level in the gingival crevicular fluid (GCF) of the patients with advanced periodontal disease

The carboxylic acids are known to be produced by the bacteria in the dental plaque. The purpose of the present study is to investigate the concentrations of carboxylic acids in the whole saliva and the gingival crevicular fluid (GCF) of periodontal patients. The effects of these acids on human gingival fibroblasts were also examined. Nine males and 9 females patients were divided into two groups (Group A and Group B), according to the differences in probing depth (PD) and alveolar bone loss. Patients of Group A had gingivitis or slight adult periodontitis (PD less than or equal to 4 mm, alveolar bone loss less than or equal to 33%), whereas patients of Group B had moderate to advanced adult periodontitis (PD greater than 4 mm, alveolar bone loss greater than 33%). Carboxylic acids in the whole saliva and the GCF which were collected from the patients of Group A and Group B were examined using high performance liquid chromatography. The effects of two carboxylic acid salts (butyrate and formate) on the proliferation of human gingival fibroblasts from normal human gingiva were also examined by cell culture. Results obtained were as follows. 1. The concentrations of four carboxylic acids (acetic, propionic, succinic and butyric acids) in the GCF collected from patients of Group B were significantly higher than that of Group A. On the contrary, all carboxylic acid contents in the whole saliva were not significantly different between the patients of Group A and Group B. 2. Formate (1 or 3 mM) showed only a small degree of inhibition against the proliferation of human gingival fibroblasts, but butyrate (3 mM) almost completely (95.2%) inhibited the proliferation of human gingival fibroblasts. 3. The results of the present study may indicate that the carboxylic acids are involved in the initiation and development of the periodontal disease and that they can be one of the indicators in the diagnosis of the periodontal disease.

Homologation of esters

Rhodium-based homogeneous catalyst systems are reported that allow the homologation of esters ▪ to occur either at the —OR' moiety, to produce ▪ or at the ▪moiety, to produce ▪. (i) In combination with Ru, the catalyst systems ensure efficient homologation of esters, for example: 2CH 3COOCH 3 + 2CO + 2H 2 → CH 3COOC 2H 5 + 2CH 3COOH (a) under mild reaction conditions (40 bar; 155 °C). (ii) In the absence of Ru, and with carboxylic acids as diluent/promoter they homologate esters to the next higher carboxylic acids, for example: CH 3COOCH 3 + 2CO + 2H 2 → CH 3CH 2COOH + CH 3COOH (b) Mechanisms for both reactions are proposed, which are supported by the identification of several intermediate reactions. The role of various organic and inorganic reaction promoters is discussed. Amongst these, phosphine oxides are exceptionally efficient in that they induce high reaction rates combined with high selectivities. Reactions (a) and (b) potentially provide two-step, methanol/synthesis gas-based routes to ethyl acetate and propionic acid, respectively.

Antitumor Activity of Polycarboxylic Acid Polymers

Abstract We have synthesized several polyanionic polymers for biological evaluation and to probe the mechanism of macrophage activation. We have determined that, while the molecular weight of the polymers is toxicologically important, the hydrophlicity, chain rigidity, and surface charge play a significant role with respect to the degree of macrophage activation. Macrophages elicited with polyanionic polymers with hydrophobic groups were cytotoxic to Lewis lung carcinoma both in vitro and in vivo. However, macrophages stimulated by polymers with high carboxylic acid group density but little hydrophobicity did not demonstrate significant antitumor activity.

Acid-catalyzed hydrolysis of (R)-4-[(1-methyl-3-oxo-1-butenyl) amino]-3-isoxazolidinone, a prodrug of cycloserine

Hydrolysis of (R)-4-[(1-methyl-3-oxo-butenyl)amino]-3-isoxazolidinone(I), a prodrug of d-cycloserine, to (R)-4-amino-3-isoxazolidinone ( d-cycloserine) and 2,4-pentandione is general acid-catalyzed by carboxylic acids. Rectangular hyperbolic plots of pseudo first-order rate constants vs total carboxylic acid buffer concentrations suggest a change in the rate-determining step, from protonation of I at low acid concentrations to hydrolysis of protonated I at high carboxylic acid concentrations.

Gas-solid chromatography with high pressure steam carrier.

Gas-solid chromatography using steam pressurized up to 10 MPa at a column temperature of 350 °C was studied. The high pressure steam was generated continuously by pumping a constant flow of water into a heated precolumn. The carrier steam pressure was adjusted between atmospheric pressure and saturation pressure at the column temperature with a needle valve connected at the end of the separation column. The retention times of the samples (e.g., polyethylene glycols, higher carboxylic acids, etc.) decreased significantly as the pressure increased even with carrier steam having the same mass flow rate. For example, when the carrier steam pressure was raised from 6.5 MPa to 8.5 MPa at a column temperature of 340 °C (Psat =14.4 MPa), the retention times of the applied samples were shortened to fifth or sixth of the initial ones ; and tailing phenomena, if they existed, were reduced to a great extent.

Synthesis and Structural Studies of Some Scandium(III) Carboxylates

Abstract Exchange reaction takes place when scandium triacetate, Sc(OOCCH3)3, is treated with excess of higher carboxylic acids, yielding the corresponding higher carboxylates of scandium with general composition, Sc(OOCR)3 where R = C2H5, CH7 i, C3H7 n and C7H15. All these derivatives have been characterized by elemental analysis and infrared spectra. The νasy (COO) and νsym (COO) frequencies reveal the bidentate behaviour of carboxylate groups suggesting six coordinated environment around the scandium ion.

Solvent Extraction Behavior of Magnesium and Calcium in Versatic Acid-Amine Systems

Abstract Quantitative extraction of calcium and magnesium in high molecular weight carboxylic acid, versatic-9, and amine systems is reported. Butanol was used as diluent. The study includes the extraction behavior as a function of pH by controlled addition of amines, such as monoethanol amine, diethanol amine, and triethanol amine, the effect of diluent, solvent concentration, and different high molecular carboxylic acids such as versatic-10, versatic-911, and SRS-100. A comparison with the β-diketone-buffer-extraction system and versatic-9-buffer system has also been studied. The proposed method is very simple, and quantitative extraction has been achieved.

Complex calcium greases from soaps of individual and mixed acids

1. The thickening power of cCa soaps increases with increasing chain length of the hydrocarbon radical in the high-molecular-weight saponifiable component. The viscosity-temperature characteristics become poorer. In order to produce cCa greases that are satisfactory in rheological characteristics and in other respects, C22 (behenic) and higher carboxylic acids must be excluded from the high molecular weight saponifiables. 2. The characteristics of a grease thickened with a cCa soap from a mixture of individual carboxylic acids will be intermediate with respect to the characteristics of greases prepared from soaps of the individual acids present in the mixture.

Studies of Solvent Extraction Behavior of Some Divalent Metals with Liquid Ion-Exchanger

Abstract A systematic study of the comparative extraction behavior of some divalent metals has been carried out with the high molecular weight carboxylic acid, namely SRS-100. Benzene is used as diluent. The study includes the extraction behavior as a function of pH, effect of diluent, metal ion concentration, solvent concentration, and finally interference of the associated elements. In almost all cases nearly quantitative extraction has been achieved. The proposed method is very simple, rapid, and is applicable both at micro and macro levels. The. method is applicable to extraction of metal ions in the presence of other commonly interfering ions present at the milligram level.

Antistatic additives for petroleum products based on chelating compounds

1. The possibility is shown of preparing antistatic additives based on salicylic acid, theβ -diketones of ferrocene and CTM and higher carboxylic acids, which are not inferior in their properties to foreign additives. 2. The additives based on salicylic acid, theβ -diketones of ferrocene and CTM, and oleic acid increase the electrical conductivity of petroleum products by factors of 103–104, which enables the accumulation of static electrical charges in refined petroleum products to be prevented.

The Reaction of Carboxylic Acids and Hydrocarbons in a Silent Electric Discharge. I. The Reaction of Acetic Acid with Ethylene

Abstract In order to ascertain the possibility of telomerization by a silent discharge, a mixture of acetic acid and ethylene was discharged in an ozonizer under various conditions. The α-C-alkylation of acetic acid which was expected to result from its discharge-induced reaction with ethylene was not observed; neither propionic acid nor higher carboxylic acids were identified by gas chromatography. However, n-butyl acetate was obtained in a good yield. The formation of the acetate can be explained as resulting from the combination of an acetoxy radical with two molecules of ethylene. The yield of the acetate, as well as those of the liquid and gaseous products, increased with a rise in the temperature and in the voltage, with the time, and with a rise in the ratio of ethylene to the acid concentration. Besides this acetate, the liquid products were confirmed to consist of ethyl methyl ketone, acetone, acetaldehyde, hydrocarbons, and ethyl and n-propyl acetates. The gaseous products were carbon dioxide, carbon monoxide, C1–C4-hydrocarbons, and hydrogen. Judging from the relative concentration of each compound in the reaction products, it may be said that the acetoxy radical (CH3COO·) and the acetyl radical (CH3CO·) are the main intermediates in this reaction system.

The purification and physicochemical properties of a lytic enzyme induced by coliphage N20F'

1. 1. The lytic enzymes induced by the infection of Escherichia coli by three mutants of bacteriophage N20F' have been isolated and purified by column chromatography. The lytic enzyme induced by each mutant has two pH optima, one at pH 5.5 and the other at pH 8.5. Relatively high concentrations of carboxylic acids and divalent cations enhance the pH 5.5 activity but inhibit at pH 8.5. However, in the presence of law concentrations of these chemicals the pH 5.5 activity is drastically reduced, while there is no effect on the pH 8.5 activity. A monomer-dimer transition has been observed for this protein. Under conditions of high carboxylic acid and divalent cation concentration monomers are the chief molecular species at both pH 5.5 and pH 8.5. Conversely, the enzymes exist perdominantly as dimers when the concentrations of both these chemicals are lowered. These experiments indicate that monomers are involved in the enzymatic activity at pH 5.5 while dimers are responsible for the activity seen under alkaline conditions. 2. 2.The amino acid content of the three mutant enzymres has been determined. End group analyses show that alanine is the N-terminal amino acid of the lytic enzymes induced by each mutant. However, the C-terminal amino acids are different. Differences in amino acid composition and C-terminal amino acids are also reflected in differences in the peptide “fingerprint maps” that were obtained. These resuts suggest that the three spintaneous mutants may arise by a “frame shift” mutation.

Study of the kinetics of radiation graft polymerization from the vapour phase on mineral powders

IT HAS been shown previously that the method of polymerization by irradiation of solid materials in the presence of monomers in the vapour state extends the possibilities of this process considerably and enables graft polymerization to be achieved not only on organic, but also on mineral substrates [1-2]. :New organo-mineral ion-exchange materials [3] and mechanically strong semiconductors [4] have been produced by this means. A process of a similar nature, based on irradiation of mineral powders in the presence of a two-component gas mixture has been applied to the synthesis of higher carboxylic acids [5]. The process of polymerization from the vapour phase on mineral surfaces has however not been studied sufficiently, in particular the fundamental kinetic relationships have not been elucidated, and knowledge of these is necessary both for selection of the optimal technological conditions and for understanding the peculiarities and mechanism of the process. From the kinetic point of view this process is of particular interest because essentially we have here a new case of heterogeneous polymerization with the distinctive feature that active eentres initiating polymerization are generated continuously during the course of the reaction throughout the entire volume of the solid phase, both in the original mineral particles and in the newly formed surface layer of polymer. This investigation is devoted to elucidation of the main kinetic relationships of radiation graft polymerization from the vapour phase on mineral surfaces. The materials selected for study were methyl methacrylate (MMA) and styrene (St) polymerized on magnesium oxide and Aerosi]. With the four systems a study was made of the dependence of the reaction rate on dose rate, temperature, vapour pressure of monomer and the degree of adsorption of the latter on the irradiated substrate. We also studied the dependence of the reaction rate on the quantity of polymer formed on the mineral powder up to formation on the mineral particles of fairly thick polymer layers, corresponding to the thickness of the grafted layers in the organo-mineral graft materials mentioned above.

有香物質の分類に関する計量心理学的研究 (その3)

The present author has examined from a psychometric point of view, the classificatory systems of odors which were proposed by Henning, Zwaardemaker, and Crocker. The principal methods employed were (1) Torgerson-Indow's multidimensional scaling, and (2) a modification of semantic differential scales. The present study consists of four experiments, two of which (VIII to IX) used the first method and the other two (X and XI) utilized the second method.The purpose of experiment (VIII) was to analyze the similarity patterns and locate some of the unpleasant odors which cause troubles in industry into a more comprehensive scheme of odors. The odorous materials sampled are shown in Table 1. Five naive subjects judged the similarities among these odors. By the application of multidimensional scaling, four factors were extracted and the results are shown in Table 4 and Fig. 1. The first factor was a pleasantunpleasant dimension. Chemically, the positive pole of this axis was represented by resinterpenoids and the negative pole was represented by nitrogen compounds and higher carboxylic acids. The second factor was a sweet-pungent dimension. These pungent “odors” are sometimes called not odors but trigeminal stimulants. The third and the fourth factors were of dubious nature as compared with the first two factors.The purpose and method of experiment (IX) was the same as the experiment (VIII) except that the number of unpleasant odors was reduced. Odorous materials sampled are shown in Table 5. The condition of this experiment differed from those of experiment (VIII) in the following points. (1) The concentrations of odorous materials were calibrated to produce nearly equi-intensive sensation. (2) Subjects were two expert perfumers (A & B of Table 6) and six naive subjects. The reliability (especially inter-judge agreement) of the naive subjects was not sufficiently high. Therefore the multidimensional scaling was applied only to the data of the experts. By the electronic computor Facom 128B, six factors were extracted, but the 4th to 6th factors may not be a real solution. The results are shown in Table 7 and Fig. 2. The first factor was pungent-sweet. Chemically the positive pole of this axis was represented by resinterpenoids, but the common characteristics for the negative pole was not clear. The second factor was persistent-heavy-spicy foul. The negative pole was represented by skatol and clearly unpleasant, but the opposite pole was not necessarily a pleasant one. The third factor was hard to interpret.It may be characteristic of the expert judgments that the hedonic tone was not found as the first or the second factor, although the fact that extremely unpleasant odors were not included in this experiment. The relative weights of the factors (including references 6 and 7) are shown in Fig. 3. Of course the weights are different for each experiment depending on the range of sampling of odorous materials. The rate of convergence of factors was relatively slow in the case of complex odors like perfumery or spices, and relatively rapid in the case of chemically pure compounds.The author has proposed (see ref. 6) 25 semantic bipolar scales (7 point rating) for the description of odors. The purpose of experiment (X) was to reduce the number of these scales. From the semantic profiles for 44 odors (described in experiment VIII to IX) we have calculated the correlation matrix of these scales (Table 8). By the application of factor analysis (centroid method), three factors were extracted (Table 9). The first factor was clearly a “sensory pleasure” dimension, the second factor was a “harshness”, and the third factor was an “intensity or vividness”.An expert perfumer Mr. Kainoshow proposed a 20 semantic monopolar scales (5 point rating) for the description of odors. In experiment (XI), we have analyzed the correlation matrix for these scales (Table 10) by