Branched-chain Type Research Articles

定電流電解重合によるZn上へのポリ2-ビニルピリジン膜の形成

Poly(2-vinylpyridine) films were deposited on Zn substrate by electropolymerization using galvanostatic technique at 30°C in pH 5 aqueous solution containing methanol. Films were also formed by employing cyclic voltammetry and potentiostatic techniques; these were compared with those formed using galvanostatic electrolysis. The thickness of films formed by galvanostatic electrolysis increased in proportion to the amount of charge passed during electropolymerization but decreased with increasing current density because of increased hydrogen evolution. The FT-IR spectra and the color of the films suggested that the structure of poly(2-vinylpyridine) films changed from the non-branched to the branched chain type with the higher current densities. The anodic current density for Zn dissolution in 3%NaCl solution was significantly decreased by coating with poly(2-vinylpyridine) films. After electropolymerization at 50 A•m-2, the anodic reaction was most inhibited, showing excellent corrosion resistance. Although the electrochemical techniques employed for the film preparation had no influence on the thickness or the structure of films, the films formed by galvanostatic electrolysis contained the fewest cracks and gave the best corrosion resistance.

Formation of Poly(2-vinylpyridine) Films on Zn by Galvanostatic Electropolymerization

Poly(2vinylpyridine) films were deposited on Zn substrate by electropolymerization using a galvanostatic technique at 30 � Ci n pH 5 aqueous solution containing methanol. Films were also formed by employing cyclic voltammetry and potentiostatic techniques; these were compared with those formed using galvanostatic electrolysis. The thickness of films formed by galvanostatic electrolysis increased in proportion to the amount of charge passed during electropolymerization but decreased with increasing current density because of increased hydrogen evolution. The FT-IR spectra and the color of the films suggested that the structure of poly(2-vinylpyridine) films changed from the nonbranched to the branched chain type at higher current densities. The anodic current density for Zn dissolution in 3% NaCl solution was significantly decreased by coating with poly(2-vinylpyridine) films. After electropolymerization at 50 A m � 2 , the anodic reaction was most inhibited, showing excellent corrosion resistance. Although the electrochemical techniques employed had no influence on the thickness or the structure of films, the films formed by galvanostatic electrolysis contained the fewest cracks and gave the best corrosion resistance.

Cellular fatty acid composition and phenotypic and cultural characterization of CDC fermentative coryneform groups 3 and 5

Seventy strains of fermentative, asporogenous, gram-positive coccobacilli or short rods form two closely related groups which have been designated CDC fermentative coryneform groups 3 (32 strains, xylose fermenters) and 5 (38 strains, xylose nonfermenters). The two taxa are otherwise similar to each other phenotypically and culturally and by a distinctive Staphylococcus-like odor and by cellular fatty acid (CFA) composition. CDC group 3 and CDC group 5 strains have been isolated from clinical sources (blood, abscesses, and wounds but not urine or respiratory specimens) in Canada and the United States and among referrals from Belgium, Sweden, and Spain. Coryneform CDC group 3 strains were phenotypically similar to CDC coryneform group A-3 but were distinguishable by their inability to reduce nitrate and by their lack of motility. Coryneform CDC group 5 isolates were phenotypically somewhat similar to Actinomyces viscosus and Rothia dentocariosa, except that none of this group reduced nitrate. Both CDC groups could be differentiated from these similar bacteria by the ability to decarboxylate lysine and ornithine. The CFA compositions of CDC group 3 and 5 strains were similar to each other, were distinctive from those of other coryneforms, and were of the branched-chain type. API CORYNE codes were consistent for both CDC group 3 and CDC group 5 bacteria, suggesting that this method could be useful as an identification method.

Cellular fatty acid composition as an adjunct to the identification of asporogenous, aerobic gram-positive rods

Cellular fatty acid (CFA) compositions of 561 asporogenous, aerobic gram-positive rods were analyzed by gas-liquid chromatography as an adjunct to their identification when grown on blood agar at 35 degrees C. The organisms could be divided into two groups. In the first group (branched-chain type), which included coryneform CDC groups A-3, A-4, and A-5; some strains of B-1 and B-3; "Corynebacterium aquaticum"; Brevibacterium liquefaciens; Rothia dentocariosa; and Listeria spp., the rods had sizable quantities of antiesopentadecanoic (Ca15:0) and anteisoheptadecanoic (Ca17:0) acids. Other species with these types of CFA included B. acetylicum, which contained large amounts of isotridecanoic (Ci13:0) and anteisotridecanoic (Ca13:0) acids. CFAs useful for distinguishing among Jonesia denitrificans, Oerskovia spp., some strains of CDC groups B-1 and B-3, Kurthia spp., and Propionibacterium avidum were hexadecanoic (C 16:0) acid, isopentadecanoic (Ci15:0) acid, and Ca15:0). The second group (straight-chained type), which included Actinomyces pyogenes; Arcanobacterium haemolyticum; C. bovis; C. cystitidis; C. diphtheriae; C. flavescens, "C. gentalium"; C. jeikeium; C. kutscheri; C. matruchotii; C .minutissimum; C. mycetoides; C. pilosum; C. pseudodiphtheriticum; "C. pseudogenitalium"; C. pseudotuberculosis; C. renale; CDC groups 1, 2, ANF-1, D-2, E, F-1, F-2, G-1, G-2, and I-2; C. striatum; "C. tuberculostearicum"; C. ulcerans; C. vitarumen; C. xerosis; and Erysipelothrix rhusiopathiae, was typified by significant quantities of hexadecanoic (C16:0) and oleic acids (C18:cis9), with differences in the amounts of linoleic acid (C18:2), stearic acid (C18:0), an unnamed peak (equivalent chain length, 14.966), and small quantities of other known saturated and unsaturated fatty acids. CFA composition of these organisms was sufficiently discriminatory to assist in classification but could not be used as the sole means of identification.

化学イオン化質量分析法によるアルキルベンゼン類の選択的検出と同定

A simple method for detection and identification of alkylbenzenes was attempted for gasoline, kerosine and industrial grade alkylbenzene mixtures by using GC/CIMS. About 1 μl of each sample was introduced into a Finnigan 4023 GC/MS/DS equipped with an OV-101 capillary column (0.28 mm i. d. ×20 m or 0.25 mm i. d. ×50 m). Methane was used as a reagent gas. The ion source pressure and temperature were maintained at 0.20 Torr and 250°C, respectively. The mass fragmentograms were recorded at the 20-25 characteristic masses, as m/z 79, 91, 92, 93, 105, 106, 107, 119, 121, 133, 135, 147, 149, 161, 163, 175, 177, 189, 191, 203, 217, 231, 245, 259, 273, corresponding to quasi-molecular ions, (M±H)+, molecular ions, M+, fragment ions, (M-CmHm-1)+ and ions formed by olefin displacement reactions, (M-CmH2m-1)+. The alkylbenzenes were detected selectively by this technique for the sample of gasoline and kerosine. Reconstructed ion chromatogram which was obtained by summing up all of the mass fragmentograms contained only the signal of the alkylbenzenes. Although the identification of each alkylbenzenes was difficult, the estimation of the molecular weights was much easier by CI than EI for the sample of industrial alkylbenzene containing branched chain type compounds. Each alkylbenzene could be identified completely in a sample containing straight chain type compounds. In general, it was found that the compounds of C7H8 to C10H14 were possible to be identified by mass fragmentography without the standard samples. For alkylbenzenes of C11H16 and later ones, the estimation of the molecular weights and the classification of groups of isomers were possible by the present method. For example, they were pentylbenzene, methylbutylbenzene…… pentamethylbenzene in the case of C11H16.

General Properties of Mixtures of Paraffinic Insulating Oil with Alkylbenzenes

Mixtures of a paraffinic-base electrical insulating oil for oil-filled transformer use with a branchedchain type alkylbenzene with high viscosity, a branchedchain type dodecylbenzene and a straight-chain type dodecylbenzene were evaluated for improving the characteristics of a paraffinic mineral oil for transformer use. It has been demonstrated that blending the alkylbenzenes in the paraffinic oil brings about some improvements in its chemical, physical, and electrical properties. Moreover, it has been concluded that a modified paraffinic oil which contains 50% of the branched dodecylbenzene gives overall characteristics almost equivalent to the naphthenic transformer oil which is practically employed.

General Properties of Mixtures of Naphtenic Insulating Oil with Alkylbenzenes

Mixtures of naphthenic base electrical insulating oil for oil-filled transformer use with a branched-chain type alkylbenzene with high viscosity, a branched-chain type dodecylbenzene and a straight-chain type dodecylbenzene were evaluated for improving the characteristics of naphthenic mineral oil for transformer use. It has been demonstrated that blending the alkylbenzene in the mineral oil brings about some improvements in its chemical and electrical properties.

Teichoic acids and lipids associated with the membrane of a Bacillus licheniformis mutant and the membrane lipids of the parental strain.

Bacillus licheniformis 6346 MH-1 and a phosphoglucomutase-deficient poorly lytic mutant, B. licheniformis 6346 MH-5, both contain cardiolipin, phosphatidyl ethanolamine, and phosphatidyl glycerol but are devoid of phosphoglycolipids. Gentiobiosyl diglyceride is present in the parent organism but glycolipids are absent from the mutant. Lipoteichoic acid was extracted from the whole cells of MH-5 with hot aqueous phenol and contained fatty acids, glucosamine, and 1,3-polyglycerol phosphate. The fatty acids were predominantly of the branched-chain type and were esterified to hydroxyl groups of a terminal glycerol residue. The polyglycerol phosphate chains contained, on average, 32 to 40 glycerol residues, some of which were substituted at the secondary hydroxyl group with alpha-N-acylglucosaminyl residues. Phenol extraction of the supernatant fluid that remained when walls were removed from preparations of disrupted cells of MH-5 yielded membrane teichoic acid, which consisted of substituted polyglycerol phosphate but was devoid of fatty acids.

Lipoteichoic acid from Bacillus licheniformis 6346 MH-1. Comparative studies on the lipid portion of the lipoteichoic acid and the membrane glycolipid.

A lipoteichoic acid and a membrane glycolipid were isolated from Bacillus licheniformis 6346 MH-1. The fatty acid composition of the two preparations were similar. Most of the fatty acids were of the branched chain type. The glycolipid was shown to be a diacyl derivative of O-beta-D-glucopyranosyl-(1 leads to 6)-O-beta-D-glucopyranosyl-(1 leads to 3)-glycerol. The lipoteichoic acid contained lipid, polyglycerol phosphate, and glucosamine. The lipid was released by treatment with hydrofluoric acid and by hydrolysis in dilute acid and was shown to have a structure identical with that of the membrane glycolipid.

Effect of Alkyl Chain Branching on the Biodegradability of Alkylbenzene Sulf onates

Degree of alkyl chain branching of various commercially available detergent alkylates, including straight chain type, branched chain type and mixture thereof, was studied by means of high-resolution nuclear maenetic resonance. and an explicit correlation between alkyl chain branching ofdetergent alkylates and biodegradability of their sulf onates was obtained.The degree of alkyl chain branching in detergent alkylates is expressed by a parameter HCH3-6 ΣH-5, which is obtained by a combination of NMR and gaschromatography, where HCH3 and Σ H - 5 denote the number of methyl hydrogens and the total number of hydrogens in the alkyl chain, respectively. A plot of this parameter for the alkyl chain branching of detergent alkylates against biodegradability of their sulfonates was found to be almost linear as in Fig.-3. Use of Hω, which denotes the number of total methyl hydrogens in the alkyl chain, instead of HCH3 in the parameter leads to a lack of the linearlity of the plot of the alkyl chain branching against the biodegradability of sulf onates as in Fig.-4. Whereas, biodegradability of alkylbenzene sulfonates can be more rapidly predicted, since Hω, can be derived only from NMR spectra of hydrogens in the alkyl chain in detergent alkylates.

STUDIES OF THE LIPIDS OF ARTHROBACTER GLOBIFORMIS 616. I. THE FATTY ACID COMPOSITION.

Nearly 96% of the fatty acids of Arthrobacter globiformis 616 cultivated in a glucose – mineral salts – nitrate medium were of the branched-chain type. The fatty acids, identified by melting point and by infrared, mass, and nuclear magnetic resonance spectra were (in order of abundance) 12-methyl tetradecanoic, 14-methyl hexadecanoic, 14-methyl pentadecanoic, hexadecanoic, 12-methyl tridecanoic, and tetradecanoic.

Gas-phase oxidation of propylene

The reaction between propylene and oxygen has been examined between the temperatures of 340 and 400°C in a static system by detailed analysis supplemented by pressure-time data. The reaction is of the degenerately branched-chain type, and acetaldehyde is mainly responsible for branching. The aldehyde is probably produced by the decomposition of a peroxide which is the initially formed molecular product. Inhibition of certain of the elementary processes which occurs at high concentrations of hydrocarbon is ascribed to the formation of an unreactive allyl radical. Reaction processes which account for the main features of the reaction and the more important intermediates and products are discussed.

THE STRUCTURE OF LINSEED MUCILAGE. PART I

The neutral polysaccharide component of linseed mucilage has been isolated and examined. On acidic hydrolysis it furnished mainly D-xylose and L-arabinose. Periodate oxidation experiments showed that the polysaccharide is of the branched chain type. Methylation experiments have confirmed this result and have given additional information on the structure of the polysaccharide.