Branched-chain Acids Research Articles

The regiospecific palladium catalysed hydrocarboxylation of alkenes under mild conditions

Alkenes react with carbon monoxide, water, oxygen, hydrochloric acid, and palladium and copper chlorides, to give branched chain acids in good yields.

Lubricity properties of additives based on higher fatty acids

This article investigates possible lubricity additive applications for a number of products separated from a C/sub 17/-C/sub 20/ fraction and still-bottoms in synthetic fatty acids (SFA) production. Each additive (MKNK, DKK, NKK and FKKO) was dissolved in a hydrotreated T-7 fuel, and lubricity properties were evaluated by the KIIGA-2 method. Finds that the branched-chain monocarboxylic and unsaturated acids recovered from the C/sub 17/-C/sub 20/ SFA fraction, and also the fraction of acids from the SFA still-bottoms, form rather strong chemisorbed films on metal surfaces, and fuel formations based on these materials have a high level of lubricity.

Gas chromatography of homologous esters

Abstract The retention behaviour of methyl, chloromethyl and isomeric methyl monochloro esters of n-carboxylic acids and of the branched-chain C5 carboxylic acids on Carbowax 20M and SE-30 capillary columns has been examined. The effect on retention of the position of the chlorine substituent and of branching in the acid chain is discussed and the results are compared with those of other studies of aliphatic esters.

Dimers of unsaturated carboxylic acids from synthetic fatty acid fractions as jet fuel corrosion inhibitors

The synthetic fatty acids (SFA) cuts contain considerable amounts of branched-chain acids and higher unsaturated acids that can be used as raw materials in producing dimers and trimers for corrosion protection. This paper examines the use of a commercial C/sub 17/-C/sub 20/ SFA cut from a petroleum refinery as the starting material in preparing dimers and trimers of higher unsaturated carboxylic acids. It investigates the synthesized dimers, which are readily soluble in hydrocarbon fuels, as corrosion inhibitors in T-8V and T-7 jet fuels, which are produced by methods involving hydrogenation. The dimers of unsaturated acids prepared from the iso-MCUA fraction give good corrosion protection of carbon steel and are essentially equal to the Santolene C in corrosion protection.

Cellular fatty acid composition of Legionella longbeachae sp. nov.

The cellular fatty acid composition of Legionella longbeachae was determined by gas-liquid chromatography. As in other Legionella species, the fatty acids of this new species are characterized by relatively large amounts of branched-chain acids.

Relationships between Pyruvate Decarboxylation and Branched-Chain Volatile Acid Synthesis in Ascaris Mitochondria

The rate of 14CO2 evolution from 1-[14C]pyruvate by intact Ascaris mitochondria was very slow, but increased with increasing concentrations of pyruvate. At all concentrations of pyruvate, in an aerobic environment, pyruvate decarboxylation was stimulated greatly by the addition of fumarate, malate, or succinate. However, under anaerobic conditions, only malate and fumarate stimulated pyruvate decarboxylation; succinate had no effect. This implies that the aerobic metabolism of succinate, presumably to other dicarboxylic acids, may be required for the stimulation. Incubation of sonicated mitochondria with pyruvate plus fumarate, under rate-limiting concentrations of NAD+, resulted in approximately equal quantities of pyruvate utilized and succinate formed, suggesting that pyruvate oxidation and fumarate reduction may be linked. Branched-chain, volatile fatty acids were not formed during incubations with either malate or succinate, or succinate plus acetate. However, incubations of intact Ascaris mitochondria with pyruvate plus succinate yielded 2-methylbutyrate and 2-methylvalerate, whereas incubations with pyruvate plus propionate yielded almost exclusively 2-methylvalerate. Oxygen dramatically inhibited the synthesis of the branched-chain acids from succinate plus pyruvate, attesting to the apparent anaerobic nature of Ascaris mitochondrial metabolism. Significantly, the addition of glucose plus ADP stimulated the formation of all volatile fatty acids. Therefore, the synthesis of branched-chain acids may be related directly to increased energy generation. Alternatively, they may function in the regulatory role of maintaining the mitochondrial redox balance.

Hydrogenated oils and fats: the presence of chemically-modified fatty acids in human adipose tissue

A total of 231 samples of adipose tissue has been analyzed for trans unsaturated acids which arise in large measure via consumption of hydrogenated fat; 136 specimens derived from patients who had died of ischemic heart disease (cases), the remainder being controls. They have also been analyzed by gas-liquid chromatography which gave information regarding the amounts of 1) "higher acids"--C20 plus C22 acids, mainly monoenoic--which derive from hydrogenated marine oils present in high amounts in certain margarines in the United Kingdom, and 2) "lower acids"--14:1 plus odd-numbered and branched chain acids in the C15 to C17 range--which are present in hydrogenated fat in lower amounts than in, say, butter-fat. Values of trans unsaturated acids tend to be higher, and values of lower acids lower for cases than controls, but we cannot at present conclude that these differences are statistically significant. Case versus control levels in respect of higher acids and linoleic acid do not appear to be significantly different.

Studies on Acholeplasma laidlawii grown on branched-chain fatty acids

Acholeplasma laidlawii B was grown on the branched-chain fatty acids, 14-methylpentadecanoic acid and 14-methylhexadecanoic acid, and the straight-chain palmitic acid. The incorporation of the branched-chain fatty acids was very effective; more than 90% of the fatty acids of the lipids of this organism consisted of the branched-chain constituents. A somewhat smaller amount (81%) was found in the cells grown with palmitic acid. Differential scanning calorimetry of the isolated membranes showed that distinct lipid phase transitions occurred in between 15 and 31 °C for the 14-methylpentadecanoic acid, 11 and 29 °C for the 14-methylhexadecanoic acid, and 14 and 36 °C for the palmitic acid-enriched membranes. Freeze-fracture electron microscopy showed that the lipid phase transitions were accompanied by particle aggregation only in the case of palmitic acid-enriched membranes. When the branched-chain acid-enriched membranes were quenched from temperatures below the onset of the lipid phase transition, a random distribution of particles on both fracture faces of the membrane was observed. The membranes were incubated with pig pancreatic phospholipase A 2 at various temperatures. Below the onset of the lipid phase transition phosphatidylglycerol was not accessible for this enzyme in palmitate-enriched membranes. However, a fast hydrolysis of 60–75% of the phosphatidylglycerol could be measured in the branched-chain acid-enriched membranes at temperatures below the onset of the lipid phase transition. The residual phosphatidylglycerol could be hydrolyzed at a slower, temperature-dependent rate. The observations show that lipids containing branched-chain acids undergo a cooperative lipid phase transition which does not result in a tight packing of the lipids of the bilayer below the phase transition.

Fatty acids in milk of marine little toothed whales Stenella attenuata.

The composition and quantity of free short-chain acids in the milk of whales Stenella attenuata and the composition of short-and long-chain acids in their milk lipids were studied. The content of lipids in the milk was about 19.7%, the REICHERT-MEISSL value about 6.1, and the content of free short-chain acids about 3.1 meq/l. Acetic, propionic, isobutyric, isovaleric, and n-enamthic acids were usually present in free form. Acetic acid was the most dominate, followed by n-enanthic and isovaleric acids. Other acids were detected in trace amounts. A series of short-chain straight acids from acetic acid to n-capric acid and a series of short-chain branched acids from isobutyric acid to isoenanthic acid were usually detected in milk lipids. Generally, actic acid was the most abundant, the straight-chain acids from proponic acid to n-capric acid were present in nearly equal amounts, but branched-chain acids were few. Long-chain branched acids in milk lipids were also prewent only in small amounts. Iso-17:0 acid showed the maximum concentration among the odd-numbered iso acids and iso-18:0 acid among the even-numbered iso acids. Few anteiso acids and few iso acids with carbon number lower than 13 were detected.

Fatty acids in blood of marine little toothed whales Stenella caeruleo-alba.

The compositions or quantities of free short-chain acids in plasma, of free and esterified short-and long-chain acids in plasma protein, and of long-chain acids in blood corpuscle lipids werestudied with adult whales Stenella caeruleo-alba which were caught alive. The concentration of free short-chain acids in blood was about 0.97 meq/l, and that in plasma was low, being combined mainly with plasma protein. Free short-chain acids were composed mostly of acetic acid; iso-valeric, propionic, isobutyric and n-butyric acids were also present in decreasing order. Several esterified short-chain acids were found in plasma protein; n-valeric and n-carpoic acids were detected, in addition to those free short-chain acids observed in blood. The ratio of acetic acid in the esterified acids was very low compared to that in the free acids. In plasma protein, long-chain branched acids were rare in both free and esterified forms. These forms had different compositions. In particular, many branched-chain acids with carbon numbers lower than 13 were recognized in the free acids, but few in the esterified acids, where the composition was similar to that of fish oil. In the long-chain straight acids in plasma protein, the amount of saturated and monoenoic acids with carbon numbers lower than 16 and total saturated acids was greater in free form and total polyenoic acids in esterified form.

An E.S.R. study of the oxidation of some malonic and other acids by hydroxyl radicals

A series of terminal dicarboxylic acids, malonic acids and branched-chain aliphatic acids on oxidation with TiC13/H2O2 in a flow system give rise to e.s.r. spectra arising from mixtures of radicals. In most cases the dominant radical is that formed by abstraction of hydrogen from the β-carbon. Malonic acids complex with titanium(III) ions sufficiently strongly to be examined at elevated pH values without the need for added ethylenediaminetetraacetic acid.

Further studies of the cellular fatty acid composition of Legionnaires disease bacteria.

The cellular fatty acid composition of 36 strains of the Legionnaires disease bacterium was determined by gas chromatography after growth on different media. The fatty acid profile of each strain was essentially identical on each medium and was characterized by large amounts (greater than 68%) of branched-chain acids.

Hydrophobic interactions in ternary zinc(II) and copper(II) complexes containing 1,10-phenanthroline or 2,2′-bipyridyl and an alkane carboxylate or sulphonate

The methyl resonances of [Me3Si(CH2)3SO3]– and of [Me3Si(CH2)2CO2]– are shifted upfield by [Zn(bipy)]2+ or by [Zn(phen)]2+, whereas Zn2+ causes no shift at all; 2,2′-bipyridyl (bipy) or 1,10-phenanthroline (phen) alone cause only much smaller upfield shifts. This effect is attributed to a hydrophobic interaction between the trimethylsilyl group and the heterocyclic aromatic ring system. The stability constants of all four ternary complexes have been determined from the variation of the n.m.r. spectra with [Zn(bipy)]2+ or [Zn(phen)]2+ concentration. The stability constants of the binary Cu2+ and Zn2+ and the ternary [Cu(bipy)]2+, [Zn(bipy)]2+, [Cu(phen)]2+, and [Zn(phen)]2+ complexes of [Me3Si(CH2)2CO2]– have been determined by potentiometric titrations, and indicate small positive values of Δ log K. The methyl resonances of a range of medium-length straight- and branched-chain carboxylic acids are also shifted, showing that a hydrophobic interaction between an aromatic group and a methyl, isopropyl, or t-butyl group can also occur in a ternary complex.

Studies on characterization and variation in triglyceride fatty acids from Puntus sarana body lipids.

AbstractBody lipids of P. sarana of four different sizes were fractionated into phospholipids, neutral lipids, nonsaponifiables, total fatty acids, polyunsaturated, monounsaturated and saturated fatty acid fractions. Percentage composition of each fraction was determined. The triglyceride fatty acids were identified by thin layer and gas liquid chromatography. C8 to C23 fatty acids including both odd numbered and branched chain acids were detected. The major constituents were C14, C15, C16, C16:1, C18 C18:1, C18:2, C18:3; forty‐three other acids were detected in lower proportions. Composition of each fatty acids and their variation with size have been discussed.tP. sarana body lipids in general showed a behavior typical of fresh water fish by having a higher percentage of saturated C16 and unsaturated C18 acids and a lower percentage of unsaturated C20 acid.

Volatile acid production from threonine, valine, leucine and isoleucine by clostridia

The amounts of the volatile acids produced from thereonine, valine, leucine and isoleucine by growing cultures of clostridia have been measured. The species used were Clostridium sporogenes; C. caloritolerans; C. botulinum proteolytic type A; C. botulinum proteolytic type B; C. botulinum proteolytic type F; C. botulinum proteolytic type G; C. putrificum; C. difficile; C. ghoni; C. bifermentans; C. sordellii; C. mangenoti; C. cadaveris; C. lituseburense; C. propionicum; C. sticklandii; C. scatologenes; C. subterminale; C. putrefaciens; C. histolyticum; C. tetanomorphum; C. limosum; C. lentoputrescens; C. tetani; C. melanomenatum; C. cochlearium; C. sporospheroides. Most of the species tested gave increased yields of propionic acid when grown in the threonine medium; in addition, some species resembled C. propionicum and produced n-butyric acid when grown in this medium. C. histolyticum produced only acetic acid in the basal medium; all seven strains of this species produced more acetic acid when grown in the threonine medium than in the basal medium. Species which oxidize valine to iso-butyric acid also oxidize leucine to 3-methyl butyric acid and isoleucine to 2-methylbutyric acid. The iso-caproic fraction produced by some species is shown to be derived from leucine. The identitity of the branched-chain acids produced by C. sporogenes has been confirmed by gas liquid chromatography/mass spectrometry.

CELLULAR FATTY ACID COMPOSITION IN PSEUDOMONAS SPECIES

Cellular fatty acid composition of 50 strains of the genus Pseudomonas was determined by gas-liquid chromatography. Straight-chain saturated acid of C16:0 and straight-chain unsaturated acids of C16:1 and C18:1 with a double bond were commonly found in all the strains tested. The presence of hydroxy acids, cyclopropane acids, and branched-chain acids showed the characteristics for the groups and species in the genus Pseudomonas. Similarity values calculated on the basis of fatty acids exhibited a clear correlation to the taxonomic groups of this genus. Bacterial fatty acid composition was considered to be useful for the study of interrelation and for rapid identification of the bacteria. Taxonomic studies on bacteria have been mainly carried out on the basis of morphological, biochemical, and physiological characteristics. Recently, chemical constituents of bacterial cells have become of interest from the point of taxonomy, and DNA base composition, cell wall composition, and type of co-enzyme Q have been used for taxonomic criteria in some taxa. The progress of instrumental analyses has contributed to the development of chemotaxonomy, and the results involved have been useful not only for the bacterial classification, but also for rapid identification of the bacteria.

Historical and marketing trends of natural/synthetic fatty acids

Abstract and SummaryAs long as a substantial portion of raw materials for natural fatty acids are relatively inexpensive by‐products of other major industries, natural fatty acids should fulfill the world's projected needs at least through 1985. Production of synthetic fatty acids may also increase; however, at the present time the cost of their raw material and processing has made them largely noncompetitive, except in a few cases. Synthetic organic acid manufacturers currently supplying short chain products will continue their efforts to enter the detergent range fatty acid market area. We expect some breakthrough in synthetics during the life of our forecast. However, potential producers have yet to develop an economically competitive synthetic fatty acid as a replacement for natural fatty acids in the U.S. Petroleum‐based products include odd, even, and branched chain acids whose performance must be proven. Finally, the petroleum base for synthetic fatty acids no longer has the price stability we have been accustomed to in the past. Recent changes in price of ethylene and forecasts are evidence of this trends for the future.

Cellular fatty acid composition of isolates from Legionnaires disease.

The cellular fatty acids of four isolates from Legionnaires disease and two antigenically related isolates were identified by gas chromatography, mass spectrometry, and associated techniques. The six isolates had essentially the same fatty acid composition, which was characterized by large amounts (greater than 80%) of branched-chain acids.

Early diagenesis of fatty acids in lacustrine sediments—I. Identification and distribution of fatty acids in recent sediment from a freshwater lake

Fatty acids have been isolated and quantitatively determined from a 1.5 m sediment core of Lake Suwa, a eutrophic lake in the central districts of Japan. The fatty acids identified by combined gas chromatography-mass spectrometry were straight-chain saturated (C 12 to C 34), monounsaturated with even carbon number (C 16 to C 24) and branched-chain ( iso, anteiso, 10-methyloctadecanoic) acids. The concentrations of the higher molecular weight (⩾ C 20) saturated fatty acids remained nearly constant throughout the core, suggesting a high degree of preservation of those acids, whereas the monounsaturated and the lower molecular weight saturated fatty acids indicated a great decrease in concentration with depth to an approximately 20cm level. It is suggested that the microbial activity in sediments causes a significant reconstruction of the fatty acid distribution during early diagenesis.

Fatty acids in fossil fruits

Fatty acids extracted from six fruit of Nyssa fissilis from the Early Tertiary Brandon Lignite, Vermont, include mainly palmitic, palmitoleic, stearic, and oleic acids and a number of probable branched chain acids. Four unidentified ‘round fruit’ from the lignite contained the same acids in predominance. The two taxa were chemically indistinguishable because of wide intraspecific variation in percentage of each n-fatty acid present. ‘Fingerprint’ chromatograms of non-aromatic hydrocarbon extracts from two distinct taxa of fruit from an Eocene clay of Tennessee also showed no consistent interspecific differences. We conclude that degradation and removal of the seed food reserves and introduction of extraneous lipids limits the utility of fatty acids and hydrocarbons in chemosystematic study of fossil fruits at the species and genus levels.