Series Of Homologous Acids Research Articles

Molecular characterization of Type I kerogen from the Green River Formation using advanced NMR techniques in combination with electrospray ionization/ultrahigh resolution mass spectrometry

This study describes a new approach for characterizing high molecular weight compounds in Type I kerogen, involving both nuclear magnetic resonance (NMR) spectroscopy and Fourier transform ion cyclotron mass spectrometry (FTICR-MS). Kerogen isolated from the Mahogany zone of the Green River Formation was examined directly using high resolution magic angle spinning (HRMAS) NMR to obtain liquid-like multidimensional spectra. It was then successively extracted with n-pentane, dichloromethane and pyridine. Pyridine extraction was also performed for comparison with the successive extractions. Using solid-state NMR, we show that the sum of the successive extracts and the single pyridine extract are quantitatively representative of the unextracted kerogen. This suggests that a non-invasive characterization of Green River kerogen can be obtained by examining the soluble extracts, all of which were subjected to ESI-FTICR-MS to identify a wide series of compounds. Series of polar CHO, CHOS and CHON compounds between C 12 and C 50+ were found. In all the extracts the two homologous series of acids (C n H 2 n O 2 and C n H 2 n −2O 4) dominated. Collision-induced dissociation was also employed to identify the different functional groups comprising the different series. The CHO series contained carboxylic acid and alkoxyl groups, whereas the CHOS and CHON series contained sulfoxide groups and nitrile-type compounds. The results also show that pyridine extraction can be used either for screening a large series of samples or for the specific study of CHO compounds. However for a detailed and complete study of the different homologous series we recommend using the successive extraction protocol.

Mass fragmentation study of the trimethylsilyl derivatives of arctiin, matairesinoside, arctigenin, phylligenin, matairesinol, pinoresinol and methylarctigenin: Their gas and liquid chromatographic analysis in plant extracts

The mass fragmentation patterns and the characteristic behavior of the trimethylsilyl (TMS) derivatives of the dibenzylbutyrolactone-type (arctiin, arctigenin, methylarctigenin, matairesinoside, matairesinol) and those of the diphenylperhydrofurotetrahydrofurane-type (phylligenin, pinoresinol) lignans, obtained by gas chromatography–mass spectrometry (GC–MS), were presented. It was shown that upon acidic hydrolysis the dibenzylbutyrolactone-type lignans are stable while the diphenylperhydrofurotetrahydrofurane-type ones decompose. As a novelty to the field we confirmed that the fragment species of the derivatized lignan glycosides, in the presence of excess hexamethyldisilazane, leaded to their in situ derivatization. Quantification of the selective fragment ions of the TMS derivatives by GC–MS, in respect of the ions found one by one, and concerning the selective fragment ions {SFI(s)} in total, provided acceptable reproducibilities, suitable for quantitation purposes: varying between 1.20% and 6.6% relative standard deviation percentages (RSD%). For characterization of the behavior of various type of lignans, analyses were performed with the untreated and with the trifluoroacetic acid hydrolyzed plant extracts, from the same sample, in parallel, both by GC–MS and by high performance liquid chromatography–mass spectrometry, working in the positive electron ionization mode (HPLC–ESPI-MS). The analysis of lignans in fruit and leaf extracts (obtained from the Arctium, Centaurea and Forsythia plants) was confirmed both by GC–MS and by HPLC–ESPI-MS. Our multicomponent system (including the identification and quantification of sugars, sugar alcohols, and several members of various homologous series of acids, anthraquinones and flavonoids) has been extended to the analysis of lignan glycosides and to the free lignans. Reproducibilities in the quantitation of lignans in plant matrices, as averages on GC and HPLC basis, varied between 0.9% and 11% (RSD). The distribution of the lignan constituents was presented for 5 Arctium, for 8 Centaurea and for 4 Forsythia plant extracts: the total of lignan contents varied between 0.42 and 87.9 mg/g, respectively.

In vitro effects of cuticular lipids of the aphids Sitobion avenae, Hyalopterus pruni and Brevicoryne brassicae on growth and sporulation of the Paecilomyces fumosoroseus and Beauveria bassiana

The exoskeleton lipids of three dangerous pests, Sitobion avenae, Hyalopterus pruni and Brevicoryne brassicae were identified by GC/MS studies. The main components found were triacylglycerols with one hexanoyl group. Fatty acid composition and position of triacylglycerols were determined from mass spectra. There was a trace of triacylglycerol with the E,E-2,4- hexadienoyl group in the extract of Brevicoryne brassicae. A series of hydrocarbons and free fatty acids were identified. Single components of straight chain aldehyde (C30) and alcohol (C32) were detected in the lipids of H. pruni, B. brassicae. Free fatty acids, including these found in the aphid lipids, were subjected to fungi-insect ecological studies. A homologous series of acids were added individually into media used to evaluate the mycelia growth and sporulation tests of the fungi, Beauveria bassiana and Paecilomyces fumosoroseus. The tests were performed in vitro and linear mycelial growth and sporulation of fungi after 14 days were measured. For both fungi, complete inhibition was observed with pentanoic and sorbic (E,E-2,4-hexadienoic) acids at a concentration as low as 0.02% w/v in both tests. Growth stimulation effects were only observed for B. bassiana with tetradecanoic and eicosanoic acid. Inhibitions were noticed for both fungi and the strongest effects were for dodecanoic (B. b.) and eicosanoic acid (P. f.). Beside free fatty acids, no other group of chemical compounds was found in the lipids which could be involved in aphids resistance to entomopathogenic fungi.

Ruthenium tetroxide oxidation of natural organic macromolecules: Messel kerogen

Molecular characterisation of Messel kerogen was undertaken using selective chemical degradation with ruthenium tetroxide (RuO 4). Eight degradation experiments were performed utilising co-oxidant/substrate (c/s) ratios (weight for (weight for weight (w/w) based upon a Total Organic Carbon (TOC) content of 53.5% for the kerogen concentrate) of 4:1, 8:1, 12:1, 16:1, 20:1, 30:1, 40:1, and 50:1 at a temperature of 25°C. Two further experiments were executed using a temperature of 35°C and c/s ratios (w/w based on TOC) of 4:1 and 16:1; the products were extracted from the former reaction and more co-oxidant added (16:1) to continue the oxidation. It was discovered that a high (20:1 and above) c/s ratios yields a high percentage of organic solvent extract and an increase in temperature liberates more products from the lower c/s ratio reaction mixtures more rapidly. For these reasons, ruthenium tetroxide completely oxidises (> 95%) the kerogen matrix at elevated (> 20:1) co-oxidant concentrations. Affects of time on the reaction (with an excess (50:1) of cooxidant and a temperature of 25°C) were also investigated; temperature and time appear to be inversely proportional to each another and directly affect reaction rates without significantly altering the products. Solvent-soluble extracts were dominated by two homologous series of acids: straight chain monocarboxylic acids (mono' acids) and α,ω-dicarboxylic acids (di' acids) (C 4C 30) indicating that polymethylene chains are important constituents of Messel kerogen. Of lesser importance was a series of acyclic isoprenoid acids (C 13C 17) and C 19C 21), and minor series of branched mono' (C 13C 17), branched di' (C 5C 11) and hopanoic' (C 30C 32) acids. This method provides valuable compositional information about the aliphatic and alicyclic portions of the kerogen. From these results, Messel kerogen appears to be a mixed type I and type II kerogen which can then be definitely classified as a type II on a van Krevelen diagram.

Esterification of Methanol with a Homologous Series of Acids Using Amberlite IR-120

Esterification of Methanol with a Homologous Series of Acids Using Amberlite IR-120

A Thermodynamic Interpretation of Solubility of the Selected Higher Fatty Alcohols and Acids in Organic Solvents

AbstractThere were discussed the thermodynamic effects, accompaning the process of dissolving higher fatty alcohols and acids in the organic solvents. It was established that the homologous series of alcohols demonstrated the uniform thermodynamic properties, independent of the even or odd nCH2 characteristics, while the homologous series of acids was evidently splittet into two separate sub‐series.

A new relation between molar sound velocity and molar volume in carboxy acid solutions

A new relationship between molar sound velocity ‘R ’ and molar volume (M/ρ) in carboxy acid solutions has been established. Using the composite ultrasonic interferometer, both monocarboxylic and dicarboxylic acid solutions in common solvents like methyl alcohol, carbontetrachloride have been studied and it has been established that a linear relationshipR =a 0 +a 1 · M/ρ holds good in all solutions of homologous series of acids in a common solvent at a particular temperature. The constantsa 0 anda 1 for a number of carboxy acid solutions have been evaluated.

The mycolipodienic acids.

A series of homologous acids, designated mycolipodienic acids, has been isolated from the lipids of tubercle bacilli as their methyl esters. Evidence is presented which shows that these esters have the structure Me·[CH2]x·CH:CH·[CH2]y·CHMe·CH2·CHMe·CH:CMe·CO2Me where the αβ-double bond has trans- and the non-conjugated double bond cis-configuration, and x and y for the main homologue are 7 and 8, respectively; C-4 and C-6 are regarded as having L-configuration. Studies of the hydrocarbons, and the saturated and unsaturated straight-chain esters isolated in the course of this work are also reported.

Surface properties of perfluoro acids as affected by terminal branching and chlorine substitution

Abstract : When an otherwise fully fluorinated carboxylic acid molecule was altered by terminal branching and terminal chlorine atom substitution, significant increases resulted in the wettability of its adsorbed monolayer. Two new homologous series of acids (CF3)2CF(CF2)nCOOH and CF2C1(CF3)CF(CF2)nCOOH, where n ranged from 11 to 1 and 9 to 1, respectively, were adsorbed as condensed monolayers on highly polished clean disks of chromium and platinum. The critical surface tension of wetting (gamma sub c) of each resulting surface was determined by contact angle measurements on homologous series of n-alkanes, open-chain polydimethylsiloxanes, and miscellaneous other liquids. In every case the wettability, expressed as gamma sub c, was increased by branching or by terminal chlorine substitution. Thus, in the series (CF3)2CF(CF2)nCOOH, gamma sub c on chromium ranged from 13.3 dynes/cm (when n = 11) to a maximum of 15.2 (when n = 1), whereas in the series CF2 C1(CF3)CF(CF2)nCOOH, gamma sub c ranged from 17.2 (when n = 9) to around 20 (when n = 1).9 These results are excellent examples of the effect on gamma sub c on substituting one terminal chlorine atom in the surface for a fluorine atom. For a given acid monolayer, almost the same gamma sub c values were obtained on each of the two metals except that gamma sub c became larger on platinum than on chromium when the acid was a lower homolog in each series. The causes of this divergence relate to a smaller adsorption site spacing and the consequent tighter molecular packing and better chain adlineation of the adsorbed compound on chromium. (Author)

Transition temperatures and transition energies of the p-n-alkoxy benzoic acids, from n-propyl to n-octadecyl

The alkoxy benzoic acids, above n-propyl, exhibit liquid crystal properties. The homologous series of acids from n-propyl to n-octadecyl has been synthesized, the transition temperatures of each member of the series measured by means of a heated-stage, polarizing microscope, and the corresponding transition energies determined by differential scanning calorimetry. Some of the acids showed solid state transitions not previously reported.

The metabolism of certain acids, amides and nitriles within plant tissues.

The plant growth-regulating activities of the first six members of the homologous series ω -(2:4-dichlorophenoxy)alkanecarboxylic acids and the corresponding amides and nitriles have been assessed in the wheat cylinder, pea curvature, pea segment and tomato-leaf epinasty tests. The breakdown of these compounds when metabolized under standard conditions in wheat coleoptile and pea-stem tissues has also been investigated using paper chromatography together with chromogenic and bio-assay procedures. In addition, colorimetric analysis was used. The alternation in activity shown by the homologous series of acids and the production of 2:4-dichlorophenoxyacetic acid and of 2:4-dichlorophenol from alternate members indicates that β -oxidation of the side-chain of these acids occurs within wheat and pea tissues. The behaviour of the amides was similar to that of the acids and explicable in terms of hydrolysis to corresponding acid within the tissue followed by β -oxidation. Only the first member of the nitrile series was active in the pea and tomato tests, though in the wheat cylinder test all showed some activity, that of the propionic derivative, however, being only slight. With the exception of this compound, the nitriles yielded 2:4-dichlorophenoxyacetic acid and all gave some 2:4-dichlorophenol when metabolized in wheat tissue. These results can be interpreted in terms of modification of the —CH 2 CN grouping by two mechanisms, viz. hydrolysis to corresponding acid, and a type of breakdown which we refer to as α -oxidation which leads to the production of the lower carboxylic acid. The acids produced by either route are then subject to β -oxidation. A study of the metabolism of 3-indolylacetonitrile provided further evidence that α -oxidation of substituted nitriles can occur in plant tissue. In this instance, the end-product of the reaction was proved to be 3-indolecarboxylic acid and the occurrence of 3-indolealdehyde as an intermediate compound was established. The mechanism of α -oxidation of nitriles is discussed and it is suggested that this may be a general reaction occurring in both plant and animal biochemistry.

Alpha-Oxidation of Omega-(2:4-Dichlorophenoxy)alkanenitriles and 3-Indolylacetonitrile within Plant Tissues

BIOLOGICAL and chemical investigations carried out here on the plant growth-regulating activity of ω-aryloxyalkanecarboxylic acids have established the importance of β-oxidation as a mechanism by which these acids are degraded in plants1. As a logical extension of this work, the corresponding nitriles were prepared and examined in the wheat cylinder elongation test (Table 1, Fig. 1) and pea curvature test (Table 1). Extracts of the wheat and pea tissues and of the solutions used in these tests were then separately examined by paper chromatography in the descending manner using butanol/ammonia/water (200:6:36 at 20° C.). The chromatograms were divided transversely into ten equal segments and each was assayed for growth-regulating activity by the wheat test. Authentic 2 : 4-dichlorophenoxy-acetic acid was also run in each experiment. By such means it was possible to correlate activity of the substance originally tested with the production of the dichlorophenoxyacetic acid, a compound highly active in the wheat cylinder test. In every instance where growth-regulating activity was shown, chrom-atographic evidence for degradation of the compound to 2:4-dichlorophenoxyacetic acid was obtained. Thus, when the homologous series of acids used in these experiments (RO(CH2)nCOOH) was treated with both wheat and pea tissue, an alternation in activity associated with β-oxidation1 was accompanied by the appearance of 2:4-dichlorophenoxy-acetic acid when n was 1, 3 and 5.