Chain Aliphatic Acids Research Articles

Screening and determination of aliphatic organic acids in commercial Brazilian sugarcane spirits employing a new method involving capillary electrophoresis and a semi-permanent adsorbed polymer coating

A simple method for the screening and determination of short chain aliphatic carboxylic acids in Brazilian sugarcane spirits by indirect capillary zone electrophoresis was developed and validated according to Eurachem guidelines. The separations were performed in a coated capillary (Ltot 73cm×Ldet 64.5cm) with 2-hydroxy-propyltrimethyl-ammonium chloride chitosan. The background electrolyte was optimized using Peakmaster® software and was composed of 21mmolL−1 β-alanine and 10mmolL−1 3,5 dinitrobenzoic acid, at pH3.6, with an applied voltage of −30kV. The method was validated for formic, lactic and acetic acids. Linearity was demonstrated and significant matrix effects were not observed at between 2.8 and 144mgL−1. The recovery (means of 89.6–117.9%) was evaluated, and ANOVA was carried out to determine the RSD values for the repeatability (2.63–8.35%) and reproducibility (1.92–6.62%). The LOD and LOQ ranged from 0.69 to 2.70 and 2.76 to 8.11mgL−1, respectively. The concentrations detected in the samples were 0.19–106.43mg per 100g.

English

Sodium Valproate is a branched chain aliphatic carboxylic acid with broad- spectrum anti-seizure activity effective in the treatment of absence, myoclonic, partial, and tonic-clonic seizures. The most common side effects are transient gastrointestinal symptoms, including anorexia, nausea, and vomiting. Liver injury may follow the inhalation, ingestion, or parenteral administration of a number of pharmacologic and chemical agents. The risk is greatest for children under two years of age and for those taking multiple medications. A rare complication in adults is a fulminant hepatitis that is frequently fatal. We would like to report a case of Sodium Valproate induced hepatitis in an elderly male who presented with dark urine, fever, generalized weakness and other symptoms suggestive of drug

A gene cluster responsible for biosynthesis of phomenoic acid in the plant pathogenic fungus, Leptosphaeria maculans

Phomenoic acid, a long chain aliphatic carboxylic acid is a major metabolite produced by Leptosphaeria maculans, a fungal pathogen of Brassica napus (canola). This fungus has 15 predicted polyketide synthases (PKS) and seven of them have the appropriate domains for the biosynthesis of phomenoic acid. The most highly expressed PKS gene after 7days growth in 10% V8 juice, PKS2, was silenced and the resultant mutant produced very low levels of phomenoic acid, indicating that this PKS is involved in phomenoic acid biosynthesis. This gene is part of a co-regulated cluster of genes. Reduced expression of an adjacent gene encoding the transcriptional regulator C6TF, led to reduced expression of genes for PKS2, P450, a cytochrome P450 monoxygenase, YogA, an alcohol dehydrogenase/quinone reductase, RTA1, a lipid transport exporter superfamily member and MFS, a Major Facilitator Superfamily transporter, as well as a marked reduction in phomenoic acid production. Phomenoic acid is toxic towards another canola pathogen Leptosphaeria biglobosa ‘canadensis’, but not towards L. maculans and only moderately toxic towards the wheat pathogen Stagonospora nodorum. This molecule is detected in infected stems and stubble of B. napus, but biosynthesis of it does not appear to be essential for pathogenicity of L. maculans. Phomenoic acid may play a role in allowing L. maculans to outcompete other fungi in its environmental niche.

Intrinsic acyl-CoA thioesterase activity of a peroxisomal ATP binding cassette transporter is required for transport and metabolism of fatty acids

Peroxisomes are organelles that perform diverse metabolic functions in different organisms, but a common function is β-oxidation of a variety of long chain aliphatic, branched, and aromatic carboxylic acids. Import of substrates into peroxisomes for β-oxidation is mediated by ATP binding cassette (ABC) transporter proteins of subfamily D, which includes the human adrenoleukodystropy protein (ALDP) defective in X-linked adrenoleukodystrophy (X-ALD). Whether substrates are transported as CoA esters or free acids has been a matter of debate. Using COMATOSE (CTS), a plant representative of the ABCD family, we demonstrate that there is a functional and physical interaction between the ABC transporter and the peroxisomal long chain acyl-CoA synthetases (LACS)6 and -7. We expressed recombinant CTS in insect cells and showed that membranes from infected cells possess fatty acyl-CoA thioesterase activity, which is stimulated by ATP. A mutant, in which Serine 810 is replaced by asparagine (S810N) is defective in fatty acid degradation in vivo, retains ATPase activity but has strongly reduced thioesterase activity, providing strong evidence for the biological relevance of this activity. Thus, CTS, and most likely the other ABCD family members, represent rare examples of polytopic membrane proteins with an intrinsic additional enzymatic function that may regulate the entry of substrates into the β-oxidation pathway. The cleavage of CoA raises questions about the side of the membrane where this occurs and this is discussed in the context of the peroxisomal coenzyme A (CoA) budget.

Synthesis and characterization of telechelic macromers containing fatty acid derivatives

Telechelic macromers end-capped with (meth)acrylic functionalities are the most commonly used materials in rigid, dental formulations. In order to provide higher flexibility to the final product (not necessarily for dental applications), long chain aliphatic fatty acid derivatives may be chosen. Thus, new telechelic macromers comprising methacrylic functionalities and dimer fatty acid derivatives have been synthesized for the first time, and their chemical structure is discussed in detail. Six different systems comprising ester, anhydride and urethane bonds were synthesized from non-toxic raw materials. FTIR spectroscopy and NMR analysis were used to evaluate chemical structure of new systems. Their molecular masses were estimated from GPC measurements and from an analytical method based on iodine value determination. The latter one proved to be very accurate in determining molecular masses of methacrylated telechelics according to a new method developed in this work. We demonstrated that, via simple organic chemistry, different architectures of telechelic macromers comprising commercially available, long chain derivatives of fatty acid, mainly linoleic acid, with α,ω-dihydroxy, α,ω-dicarboxy or α,ω-diamino functionalities were successfully synthesized. These macromers facilitate the development of new reactive (preferably, photocurable) flexible systems for potential biomedical applications.

Supercritical fluid extraction of triterpenic acids from Eucalyptus globulus bark

Eucalyptus globulus bark contains four significant families of compounds, namely triterpenic (TT) acids (betulinic, betulonic, oleanolic and ursolic acids, and the acetylated forms of the latter two), long chain aliphatic alcohols, fatty acids, and sterols. The first group is the most abundant and possesses demonstrated bioactivity, which raises the importance of this biomass. The supercritical fluid extraction (SFE) of E. globulus bark was carried out in this work with carbon dioxide at 100, 140 and 200bar, and 40, 50 and 60°C, and the extracts were analyzed by GC–MS. The results are compared with those obtained by Soxhlet with dichloromethane, and the influence of the operating conditions upon the global yield and the individual yields of the triterpenic acids is discussed in detail. The acetylated TT acids imparted a large effect on the extraction yields, as they appeared in large concentrations on the extracts independently of their absolute loadings in the bark. The polarity of the free acids, higher than that of their acetyl derivatives, justifies this behavior. Modeling calculations were also performed for interpreting the SFE results. The experimental observations are in agreement with predictions accomplished for the solubilities and mass transfer fluxes of ursolic acid and 3-acetylursolic acid that were chosen as key TT acids in the process.

Positive molecular ions and ion‐neutral complexes in the gas phase: Structure and stability of C2H4O2+· and C2H4O22+ isomers

AbstractThe structure and stability of several C2H4O2+· and C2H4O22+ isomers were studied by quantum chemical methods in an attempt to elucidate their most stable molecular arrangements and infer their contribution to the ion chemistry of astrophysical environments. The geometry optimizations were performed at B3LYP/6‐311G** and MP2/6‐311G** level. Single‐point calculations at equilibrium geometries were performed at left eigenstate completely renormalized coupled cluster method, CR‐CCL(2,3). Ninety minimum structures for the ions at the MP2 level were found: 38 related to C2H4O2+·, 33 to C2H4O22+, and 19 to ion‐neutral complexes. The more stable C2H4O2+· isomers have enolic structures, in agreement with the McLafferty rearrangement mechanism of straight chain aliphatic acids. In contrast, the most stable C2H4O22+ isomer has an acyclic OCCO nonplanar linear chain structure, with terminal +OH2 and CO+ linkages. In addition, acetic acid and methyl formate analogue structures were found only for the monopositive ion, with higher energies though. Both global minima are significantly different from the more stable neutral isomers and, therefore, could not be found in a geometry optimization procedure starting from the neutral structures. Dissociative recombination reaction pathways of C2H4O2+· and its application to the formation of astrophysical neutral molecules are also discussed. © 2012 Wiley Periodicals, Inc.

Trichome-derived O -acyl sugars are a first meal for caterpillars that tags them for predation

Plant glandular trichomes exude secondary metabolites with defensive functions, but these epidermal protuberances are surprisingly the first meal of Lepidopteran herbivores on Nicotiana attenuata. O-acyl sugars, the most abundant metabolite of glandular trichomes, impart a distinct volatile profile to the body and frass of larvae that feed on them. The headspace composition of Manduca sexta larvae is dominated by the branched chain aliphatic acids hydrolyzed from ingested O-acyl sugars, which waxes and wanes rapidly with trichome ingestion. In native habitats a ground-hunting predator, the omnivorous ant Pogonomyrmex rugosus, but not the big-eyed bug Geocoris spp., use these volatile aliphatic acids to locate their prey.

PM-IRRAS studies of the adsorption and stability of organophosphonate monolayers on passivated NiTi surfaces

Alkylphosphonic acids of different alkyl chain lengths were adsorbed on electrochemically polished NiTi surfaces from ethanolic solutions. The electropolishing process led to passive films mainly composed of Ti-oxyhydroxide. The surface showed nanoscopic etching pits with a depths of about 2 nm and a diameter of about 20 nm. The interfacial binding mechanism of the phosphonic acid group to the oxyhydroxide surface and the ordering of the monolayer were spectroscopically analysed by means of infrared reflection absorption FTIR-spectroscopy with (PM-IRRAS) and without (IRRAS) photoelastic modulation. The comparison of IRRAS and PM-IRRAS data of the long chain octadecylphosphonic acid monolayer proved that the binding mechanism of the phosphonic acid group to the oxyhydroxide surface is based on a mono- or bidentate bond, which is not stable in the presence of high water activities. An alkyl chain length of 17 CH 2 groups is required for the formation of self-assembled monolayers, which are stable in aqueous environments. These long chain aliphatic organophosphonic acid monolayers were shown to inhibit anodic and cathodic surface reactions.

Two Lysine Residues in the Bacterial Luciferase Mobile Loop Stabilize Reaction Intermediates

Bacterial luciferase catalyzes the reaction of FMNH(2), O(2), and a long chain aliphatic aldehyde, yielding FMN, carboxylic acid, and blue-green light. The most conserved contiguous region of the primary sequence corresponds to a crystallographically disordered loop adjacent to the active center (Fisher, A. J., Raushel, F. M., Baldwin, T. O., and Rayment, I. (1995) Biochemistry 34, 6581-6586; Fisher, A. J., Thompson, T. B., Thoden, J. B., Baldwin, T. O., and Rayment, I. (1996) J. Biol. Chem. 271, 21956-21968). Deletion of the mobile loop does not alter the chemistry of the reaction but decreases the total quantum yield of bioluminescence by 2 orders of magnitude (Sparks, J. M., and Baldwin, T. O. (2001) Biochemistry 40, 15436-15443). In this study, we attempt to localize the loss of activity observed in the loop deletion mutant to individual residues in the mobile loop. Using alanine mutagenesis, the effects of substitution at 15 of the 29 mobile loop residues were examined. Nine of the point mutants had reduced activity in vivo. Two mutations, K283A and K286A, resulted in a loss in quantum yield comparable with that of the loop deletion mutant. The bioluminescence emission spectrum of both mutants was normal, and both yielded the carboxylic acid chemical product at the same efficiency as the wild-type enzyme. Substitution of Lys(283) with alanine resulted in destabilization of intermediate II, whereas mutation of Lys(286) had an increase in exposure of reaction intermediates to a dynamic quencher. Based on a model of the enzyme-reduced flavin complex, the two critical lysine residues are adjacent to the quininoidal edge of the isoalloxazine.

Quinoline based receptor in fluorometric discrimination of carboxylic acids

Quinoline and naphthalene-based fluororeceptors 1 and 2 have been designed and synthesized for detection of hydroxy carboxylic acids in less polar solvents. The receptor 1 shows monomer emission quenching followed by excimer emission upon hydrogen bond-mediated complexation of carboxylic acids. The excimer emission distinguishes aromatic dicarboxylic acids from aliphatic dicarboxylic acids and even long chain aliphatic dicarboxylic acids from short chain aliphatic dicarboxylic acids. The receptor 1 is found to be selective for citric acid with a strong excimer emission in CHCl3. On the contrary, the receptor 2 exhibited less binding constant value and did not form any excimer upon complexation with the same acids under similar conditions. This established the role of quinoline ring nitrogen in binding with the acids.

A promiscuous aminoacyl-tRNA synthetase that incorporates cysteine, methionine, and alanine homologs into proteins

A mutant Escherichia coli leucyl-tRNA synthetase has been evolved for the selective incorporation of the methionine homolog 1 into proteins in yeast. This single aminoacyl-tRNA synthetase is capable of charging an amber suppressor Ec tRNA CUA Leu with at least eight different amino acids including methionine and cysteine homologs, as well as straight chain aliphatic amino acids. In addition we show that incorporation yields for these amino acids can be increased substantially by mutations in the editing CP1 domain of the E. coli leucyl-tRNA synthetase.

Synthesis, characterization and spectral studies of various newer long chain aliphatic acid (2-hydroxy benzylidene and 1H-indol-3-ylmethylene) hydrazides as mosquito para-pheromones

여러가지 긴 사슬 지방산 하이드라지드는 방향족과 헤테로 고리 알데히드와 반응하여 알코올 용매하에서 2- hydroxy benzylidene와 새로운 모기 파라-페로몬인1H-indol-3-ylmethylene hydrazides을 얻었다. 마이크로파의 조사기 술과 마찬가지로 전통적인 방법에 의한 다양한 새로운 긴고리 지방산 하이드라지드 (2-hydroxy benzylidene와 1Hindol- 3-ylmethylene)의 합성방법도 보고한다. 이 화합물들의 구조는 FTIR, NMR & MS와 같은 분광학적 기법에 의해 증명되었다. 이 화합물의 전자충격질량스펙트럼 분쇄 패턴의 몇 가지 재미있는 특징도 논의했다. Various long chain aliphatic acid hydrazides react with aromatic and heterocyclic aldehydes in alcoholic medium in refluxing conditions to give corresponding 2-hydroxy benzylidene and 1H-indol-3-ylmethylene hydrazides, a newer class of mosquito para-pheromones. We describe here synthesis of various novel long chain aliphatic acid (2- hydroxy benzylidene and 1H-indol-3-ylmethylene) hydrazides by conventional as well as microwave irradiation techniques. The structures of these compounds have been confirmed by spectroscopic techniques (FTIR, NMR & MS). Some of the interesting features of the electron impact mass spectral fragmentation pattern of these compounds have also been discussed.

Novel and recurrent ALDH3A2 mutations in Italian patients with Sjögren–Larsson syndrome

Sjögren-Larsson syndrome (SLS; MIM#270200) is an autosomal recessive neurocutaneous disease caused by mutations in the ALDH3A2 gene for fatty aldehyde dehydrogenase (FALDH), a microsomal enzyme that catalyzes the oxidation of medium- and long- chain aliphatic aldehydes fatty acids. We studied two unrelated Italian SLS patients with ichthyosis, developmental delay, spastic diplegia and brain white matter disease. One patient was homozygous for a novel ALDH3A2 insertion mutation (c.767insA) in exon 5. The other SLS patient was a compound heterozygote for two previously reported mutations: a slice site mutation (c.1094C > T; S365L) in exon 7. Analysis of fibroblast RNA by RT-PCR indicated that the spice-site mutation caused skipping of exons 2 and 3. The c.1094C > T mutation, previously associated with two ALDH3A2 haplotypes, was found on a third distinct haplotype in our patient, which indicates that arose independently in this kindred. These results add to understanding of the genetic basis of SLS and will be useful for DNA diagnosis of this disease.

A green approach for the synthesis of long chain aliphatic acid esters at room temperature

Fischer esterification of long chain aliphatic acids with methanol and ethanol could be promoted by two novel Brønsted acidic ionic liquids that bear an aromatic sulfonic acid group on the imidazolium or pyridinium cation. The reactions carried out smoothly at room temperature with good to excellent isolated yields (85–99%) under solvent-free conditions in the presence of 10 mol% ionic liquids. These ionic liquids could be recovered easily and recycled three times without any significant loss in catalytic activity.

Molecular Assembly and Photophysical Properties of Quaternary Molecular Hybrid Materials with Chemical Bond

In this paper, two long chain aliphatic carboxylic acids (oleic acid [OLA] and stearic acid [STA]) are modified with cross-linking molecules (N-2-aminoethyl-3-aminopropyl-methyl-dimethoxylsiliane, (AEAPMMS, H(2) N(CH(2))(2)HN(CH(2))(3)SiCH(3)(OCH(3))(2) and 3-aminopropyl-methyl-diethoxylsiliane (APMES, H(2) N(CH(2))(3)SiCH(3)(OC(2)H(5))(2)) resulting in four new kinds of structural molecular bridge OLA (STA)-AEAPMMS (APMES). Subsequently, ternary molecular complex systems with four molecular bridges OLA (STA)-AEAPMMS (APMES) and 2,2-bipyridyl (bipy) of lanthanides (terbium and europium) or zinc ions were assembled, which resulted in four novel kinds of quaternary molecular hybrid materials (named as bipy-Ln (Zn)-OLA (STA)-AEAPMMS (APMES) with strong chemical bonds (N-Ln(Zn)-O coordination bonds and Si-O covalent bonds) after a sol-gel (cohydrolysis and copolycondensation) process of the modified molecular bridges (as structural ligand) with inorganic precursor (tetraethoxysilane, TEOS). And especially bipy behaves as functional ligand to sensitize the luminescence of terbium or europium ions through the effective intramolecular energy transfer process, which gives rise to the characteristic emission of metal ions. The design and assembly from structural and functional ligands can help achieve a candidate technology for molecular hybrids.

Comparative study of lipophilic extractives of hardwoods and corresponding ECF bleached kraft pulps

The lipophilic extractives of Eucalyptus globulus , Eucalyptus grandis , Eucalyptus urograndis , Betula verrucosa and Acacia mangium woods and of the corresponding ECF bleached kraft pulps, were characterised by GC-MS. The five hardwoods showed significant differences in the content and composition of the main families of extractives, namely fatty acids, long chain aliphatic alcohols and sterols. Significant differences in the composition persist after wood pulping and ECF bleaching of pulps. The fate of the various types of extractives during the wood and pulp processing is discussed. Long chain aliphatic acids and alcohols are quite stable during the pulp production and are retained to a great extent in the final bleached pulp; delta 5 sterols are mostly oxidised and partially retained in the pulps, while delta 7 sterols are completely degraded and/or dissolved. B. verrucosa and A. mangium bleached pulps show contents of fatty acids about 4 and 20 times higher than that of Eucalyptus pulps, respectively, while the content of long chain aliphatic alcohols in A. mangium pulp is of the order of 100 times higher than Eucalyptus and B. verrucosa pulps.

Esterification of Long Chain Aliphatic Acids with Long Chain Alcohols Catalyzed by Multi‐Valent Metal Salts.

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Contribution of a selected fungal population to the volatile compounds on dry-cured ham

Dry-cured ham is obtained after several months of ripening. Different fungi strive on the surface, including toxigenic molds. Proteolysis and lipolysis by the endogenous and microbial enzymes seem to play a decisive role in the generation of flavor precursors in dry-cured meat products. In addition, fungi show a positive impact on the volatile compounds of ripened pork loins. However, the contribution of the fungal population to flavor formation in dry-cured ham remains unclear. One selected strain each of Penicillium chrysogenum and Debaryomyces hansenii was inoculated as starter cultures on dry-cured ham. Volatile compounds extracted by solid phase micro-extraction technique were analyzed by gas chromatography/mass spectrometry. A trained panel evaluated flavor and texture of fully ripened hams. The wild fungal population on non-inoculated control hams correlates with higher levels of short chain aliphatic carboxylic acids and their esters, branched carbonyls, branched alcohols, and some sulfur compounds, particularly at the outer muscle. Conversely, P. chrysogenum and D. hansenii seem to be responsible for higher levels of long chain aliphatic and branched hydrocarbons, furanones, long chain carboxylic acids and their esters. The very limited impact of P. chrysogenum on pyrazines in inoculated hams can be due to the activity of the yeast. Lower levels for some of the more volatile linear carbonyls at the ham surface suggest an anti-oxidant effect by micro-organisms. The differences in volatile compounds did not show a neat impact on flavor in the sensorial analysis. Nonetheless, inoculated hams got a better overall acceptability, which has to be attributed to their improved texture. The lower toughness of inoculated hams is a direct consequence of an early settling of a highly proteolytic mold. Thus, the use of selected fungi as starter cultures may be useful to obtain high-quality and safe dry-cured ham.

Efficient Esterification of Long Chain Aliphatic Carboxylic Acids with Alcohols over ZrOCl2×8H2O Catalyst.

Direct condensation of equimolar amounts of long chain carboxylic acids and alcohols could be achieved by using zirconyl chloride as an efficient catalyst. ZrOCl 2 .8H 2 O showed high activity for esterification between primary acids and alcohols; however, it was less active in the combination of branched acid and secondary alcohols to give the corresponding esters.