Dicarboxylic acids and hydroxy fatty acids in different species of fungi

Secondary metabolites of fungi can be responsible for allergies; therefore, the identification of compounds produced by these organisms is very important. Fungi produce large amounts of secondary metabolites, which belong to groups of chemicals such as: dicarboxylic acids, hydroxy acids, alcohols, hydrocarbons, esters, fatty acids, sterols, amino acids and mycotoxins. The presence of all these compounds in human proximity contributes to many diseases. Therefore, the aim of the study was a qualitative and quantitative analysis of hydroxy and dicarboxylic acids produced by fungi occurring in student hostel in Poland, in the province of Pomerania. The following species of fungi were subjected to extraction: Aspergillus niger, Aspergillus fumigatus, Aspergillus candidus, Rhizopus sp., Geotrichum candidum, and Penicillium chrysogenum. A mixture of ethyl acetate and methanol was used for the extraction. The obtained extracts were further analyzed by gas chromatography mass spectrometry (GC–MS). In all samples of fungi, the presence of a total of 22 acids, including 13 dicarboxylic and 9 hydroxy acids, was confirmed. Most acids (17 different acids) were identified in A. fumigatus. Only 10 acids were identified in the mycelium of G. candidum and A. niger. Acids which were identified in all samples of the mycelium were 22-hydroxydocosanoic acid, 24-hydroxytetracosanoic acid and adipic acid. The most abundant compounds were 22-hydroxydocosanoic acid in A. fumigatus, A. candidus, Rhizopus sp., G. candidum and P. chrysogenum, and succinic acid in A. niger. More experiments are needed to understand the physiological role of hydroxy and dicarboxylic acids. We hope that our results are an important contribution to further studies on the human health.     

Electrophilic ipso-iodination of silylated arylboronic acids

Silylated functionalized arylboronic acids were converted into corresponding iodinated arylboronic acids in good yields via the electrophilic ipso-desilylation effected with iodine chloride in refluxing CHCl₃. Disilylated arylboronic acids were susceptible to diiodination. In addition, the structural characterization and reactivity of a novel sterically hindered ortho-silylated diarylborinic ester were reported. The potential of selected iodinated phenylboronic acids as monomers for the Suzuki-Miyaura cross-coupling polymerization was demonstrated.     

Synthesis of retro-inverso peptides employing isocyanates of N-Fmoc-amino acids/peptide acids catalyzed by DMAP

The Goldschmidt-Wick type reaction between isocyanates of N^α-Fmoc-amino acids/peptide acids and N^α-Boc-/Z-/Bsmoc-amino acids catalyzed by DMAP leads to the incorporation of a reversed peptide bond. It was found to be a simple, efficient and clean reaction. All the retro-inverso peptides made were obtained as crystalline compounds in 70-92% yields.     

Synthetic epoxy-mycolic acids

We report the synthesis of single enantiomers of epoxy-mycolic acids containing an α-methyl-trans-alkene or a cis-cyclopropane with structures that match those of major isomers of such molecules present in complex mixtures in Mycobacteria such as Mycobacterium fortuitum or Mycobacterium smegmatis     

Active-sodium-promoted reductive cleavage of halogenated benzoic acids

The outcome of the reaction between 1,2-diaryl-1,2-disodioethanes and halogenated benzoic acids strongly depends on the nature of both reaction partners. Indeed, whilst chloro-, bromo- and iodobenzoic acids are easily dehalogenated, the reductive cleavage of fluorobenzoic acids proceeds to a high extent only in the presence of the dianions endowed with more powerful reducing properties. Moreover, it was observed that ortho-substituted benzoic acids are more easily dehalogenated than the corresponding para or meta isomers. These observations allowed the development of reaction conditions for the exhaustive or regioselective cleavage of selected polyhalogenated benzoic acids.     

Synthesis of nucleoside aminooxy acids

First nucleoside aminooxy acids were synthesized from furanoid sugar phthalimidooxy acids by N-glycosylation with uracil, thymine, N-benzoylcytosine, 6-N-benzoyladenine and 2-N-acetyl-6-O-diphenylcarbamoylguanine. Boc or Fmoc protected uridine aminooxy acid derivatives have also been prepared. As oxyamine protecting group, the phthalimido group was shown to be instable in MeOH, leading to the imide ring-opening product in a reversible way. This reaction was accelerated under acid or basic conditions. A uridine dimer linked by N-oxy amide has also been prepared by coupling of uridine aminooxy ester with uridine phthalimidooxy acid. These nucleoside aminooxy acids might constitute useful building blocks for the development of novel RNA mimics and conjugates with other biomolecules or reporter compounds.     

Determination of polyfluoroalkyl phosphoric acid diesters, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, perfluoroalkyl carboxylic acids, and perfluoroalkane sulfonic acids in lake trout from the Great Lakes region

A comprehensive method to extract perfluoroalkyl carboxylic acids, perfluoroalkane sulfonic acids, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, and polyfluoroalkyl phosphoric acid diesters simultaneously from fish samples has been developed. The recoveries of target compounds ranged from 78?% to 121?%. The new method was used to analyze lake trout (Salvelinus namaycush) from the Great Lakes region. The results showed that the total perfluoroalkane sulfonate concentrations ranged from 0.1 to 145?ng/g (wet weight) with perfluorooctane sulfonate (PFOS) as the dominant contaminant. Concentrations in fish between lakes were in the order of Lakes Ontario ≈ Erie > Huron > Superior ≈ Nipigon. The total perfluoroalkyl carboxylic acid concentrations ranged from 0.2 to 18.2?ng/g wet weight. The aggregate mean perfluorooctanoic acid (PFOA) concentration in fish across all lakes was 0.045?±?0.023?ng/g. Mean concentrations of PFOA were not significantly different (p?>?0.1) among the five lakes. Perfluoroalkyl phosphinic acids were detected in lake trout from Lake Ontario, Lake Erie, and Lake Huron with concentration ranging from non-detect (ND) to 0.032?ng/g. Polyfluoroalkyl phosphoric acid diesters were detected only in lake trout from Lake Huron, at levels similar to perfluorooctanoic acid.     

Highly enantioselective hydrogenation of 2-oxo-4-arybutanoic acids to 2-hydroxy-4-arylbutanoic acids

The Ru-catalyzed asymmetric hydrogenation of 2-oxo-4-arybutanoic acids to afford 2-hydroxy-4-arybutanoic acids was accomplished by employing SunPhos as chiral ligand and 1 M aq HBr as additive. The high enantioselectivities (88.4%-92.6% ee) and efficiency (TON=10,000, TOF=300 h⁻¹) make this method efficient for the synthesis of an important intermediate, (R)-2-hydroxy-4-phenylbutanoic acid, for ACE inhibitors.     

Oxygenated acids of the lipids ofOnopordum acanthium seeds

The structures of the oxygenated fatty acids of the lipids ofOnopordum acanthium L. seeds have been studied by the methods of chemical, chromatographic, and spectral analyses. Triepoxy acids of the C₁₈ series and 24 monohydroxy acids with chain lengths of C₁₄–C₁₈ have been identified, of which the 8-OH-9Z,12Z-18:2 and the 14-OH-9Z,12Z-18:2 acids have been isolated as natural compounds for the first time.     

Photochemical chlorination of alkanoic acids anchored to a polymeric support

The synthesis of 2-(poly-p-styryl)ethyl esters of hexanoic, heptanoic, octanoic, nonanoic and decanoic acids as well as (poly-p-styryl)methyl octanoate and poly-2-(nitro-p-styryl)ethyl octanoate are described and their photochlorination are studied and compared with the monomeric (conventional) photochlorination of the methyl, benzyl and 2-phenylethyl esters of these acids. Hypotheses are advanced to explain the results on monochlorination products.     

Parallel synthesis of homochiral β-amino acids

The parallel asymmetric synthesis of an array of 30 β-amino acids of high enantiomeric purity using the conjugate addition of homochiral lithium N-benzyl-N-(α-methylbenzyl)amide as the key step is accomplished. The experimental simplicity and highly practical nature of the protocol is demonstrated by the efficient parallel conversion of 15 α,β-unsaturated esters to both enantiomeric series of the corresponding β-amino acids in high overall yields and selectivities with minimal purification involved in each step of the reaction protocol.     

Thermodynamic study of fatty acids adsorption on different adsorbents

This work has as objective the study about the adsorption behavior of fatty acids (acetic, propionic, and butyric) on activated carbon and on modified and unmodified montmorillonite clays as a function of temperature and initial concentration of the adsorbate, through adsorption isotherms and their thermodynamic parameters (ΔG, ΔH, and ΔS). The activated carbon presented a higher adsorption capacity due to its relatively large surface area, compared to others adsorbents. The polar characteristic of fatty acids decreased with the increase in the length of non-polar hydrocarbon chain, improving the affinity between the activated carbon (non-polar adsorbent) and the acids. The adsorption capacity of modified montmorillonite (polar adsorbent) was favored due to the presence of the organic cation among its layers, which make the surface more hydrophobic and organophilic when compared to the unmodified montmorillonite surface. The amount of fatty acids adsorbed in the adsorbents surface increased with the concentration, at constant temperature, and decreased with the increase of temperature, at constant concentration. The amount of fatty acids adsorbed in the three adsorbents was related to the surface area and polarity of the adsorbent, concentration and solubility of the adsorbate and temperature of the solution. The negative values of ΔG and ΔH showed that the adsorption on activated carbon and on modified and unmodified montmorillonite clays was a spontaneous and an exothermic process. The decrease in the values of ΔG, with the increase of temperature, demonstrated that the adsorption was benefited by the high temperature and the positive values of ΔS showed that the fatty acids molecules were in a more randomic condition in the adsorbed state than in solution. The experimental results obtained at the temperatures of (298, 303, 313, and 323) K showed that experimental data were well represented by the Langmuir and Freundlich isotherms models.     

A new direct synthesis of cinnamic acids from aromatic aldehydes and aliphatic carboxylic acids in the presence of sodium borohydride

Cinnamic acids have been prepared in 59-86% yields by a new direct synthesis from aromatic aldehydes and aliphatic carboxylic acids in the presence of sodium borohydride and N-methyl-2-pyrrolidinone (NMP) as solvent, at reflux (185-190°C), for 9-12 hours. Without sodium borohydride, this reaction is not possible.     

Synthesis and magnetic resonance studies of some phosphinous acids,phosphorylacetic acids,and some of their coordination compounds

The synthesis of phosphorylacetic acids, RR′P(O)CH₂COOH, where R = C₆H₅ and R′ = OC₂H₅, C₂H₅, i-C₃H₇, n-C₄H₉, sec-C₄H₉ and C₆H₅, from the appropriate phosphinous acids, several of which are previously unreported, is discussed. ³¹P nuclear magnetic resonance spectra are reported for the phosphinous acids, RR′P(O)H, the phosphorylacetic acids and the metal derivatives of the phosphinous acids, RR′POM, where M in Na or MgBr, which are intermediates in the synthesis. The diastereoisomers of Phsec-BuP(O)H exhibit different ³¹P NMR spectra. Diastereotopic protons of the phosphinous acids and phosphorylacetic acids do not exhibit complex PMR spectra, whereas the diastereotopic methyl groups of the isopropyl compounds do. Some metal complexes of the phosphorylacetic acids are reported.     

Coelectroosmotic capillary electrophoresis of phenolic acids and derivatized amino acids using N,N-dimethylacrylamide-ethylpyrrolidine methacrylate physically coated capillaries

Two different families of compounds, i.e., phenolic and amino acids have been separated by capillary electrophoresis using a physically adsorbed polymer as capillary coating. The polymer used was N,N-dimethylacrylamide-ethylpyrrolidine methacrylate (DMA-EpyM) and it provided an stable coating by only flushing the capillary with a DMA-EpyM aqueous solution for 2 min between runs. The usefulness of this procedure has been demonstrated through the fast analysis of different families of solutes. Two different detection systems, diode-array detector and laser-induced fluorescence, have been used to determine phenolic acids and derivatized amino acids with fluorescein isothiocyanate, respectively. The main factors affecting reversal of electroosmotic flow (EOF) such as pH, type and concentration of buffer, and concentration and influence of organic solvents, as well as all the instrumental conditions were studied and optimized for both families of compounds.     

Peptides of aminonucleic acids

Polyamino acids with degrees of polymerization on the order of 9–10 were obtained by polymerization of p-nitrophenyl esters of β-(1-pyrimidyl)-α-alanines. Their hybridization with RNA is demonstrated.     

New N-acylamino acids and derivatives from renewable fatty acids: gelation of hydrocarbons and thermal properties

This work reports the synthesis of new fatty N-acylamino acids and N-acylamino esters from the C16:0, C18:0, C18:1, and C18:1(OH) fatty acid families and demonstrates the activity of these compounds as organogel agents. Compounds were heated and dissolved in various solvents (n-hexane, toluene, and gasoline). Only saturated C16:0 and C18:0 derived from alanine were able to form gels in toluene, and saturated C16:0 derived from phenylalanine showed gelation in n-hexane. This is the first evidence that fatty N-acylamino esters and N-acylamino acid derivatives of l-serine and fatty acids C16:0, C18:0, and C18:1 are able to form gels with hexane. This observation confirms the importance of the hydroxyl group in the segment derivative of l-serine in forming good gels.     

Rhodium/zinc co-catalyzed asymmetric ring opening reactions of oxabenzonorbornadienes with carboxylic acids

The asymmetric ring opening reactions of oxabenzonorbornadienes with carboxylic acids are described. By using the complex of [Rh(COD)Cl]₂ and (S,S)-BDPP, with ZnI₂ as the co-catalyst, a range of aromatic acids and alkyl acids were utilized as nucleophiles to afford the corresponding chiral hydronaphthalene products with high enantioselectivities (84–94% ee). Thus, the present methodology has provides an effective synthetic method for the preparation of enantioenriched hydronaphthalenes.     

A new biocatalyst for the preparation of enantiomerically pure 2-arylpropanoic acids

A new biocatalyst, a strain of Pseudomonas fluorescens MTCCB0015, is described, which produces ibuprofen, ketoprofen and flurbiprofen as enantiomerically pure (S)-2-arylpropanoic acids from their corresponding racemic esters. 2-Arylpropanoic acids are an important class of non-steroidal anti-inflammatory compounds, whose anti-inflammatory activity is mainly due to the (S)-enantiomer.     

The first synthesis of single enantiomers of ketomycolic acids

We report the synthesis of single enantiomers of two protected ketomycolic acids, one containing a cis-cyclopropane the other an α-methyl-trans-cyclopropane, and of related hydroxy-mycolic acids.