NMR-Based Metabolomics Reveals That Conjugated Double Bond Content and Lipid Storage Efficiency in HepG2 Cells Are Affected by Fatty Acidcis/transConfiguration and Chain Length

2011 ◽  
Vol 59 (16) ◽  
pp. 8994-9000 ◽  
Author(s):  
Heidi Najbjerg ◽  
Jette Feveile Young ◽  
Hanne Christine Bertram
Keyword(s):  
Double Bond ◽  
Chain Length ◽  
Hepg2 Cells ◽  
Lipid Storage ◽  
Storage Efficiency ◽  
Double Bond Content

scholarly journals Nighttime oxidation of surfactants at the air–water interface: effects of chain length, head group and saturation

2018 ◽  
Vol 18 (5) ◽  
pp. 3249-3268 ◽  
Author(s):  
Federica Sebastiani ◽  
Richard A. Campbell ◽  
Kunal Rastogi ◽  
Christian Pfrang
Keyword(s):  
Oleic Acid ◽  
Double Bond ◽  
Methyl Ester ◽  
Reaction Kinetics ◽  
Chain Length ◽  
Rate Coefficients ◽  
Head Group ◽  
Water Interface ◽  
Organic Monolayers ◽  
Air Water Interface

Abstract. Reactions of the key atmospheric nighttime oxidant NO3 with organic monolayers at the air–water interface are used as proxies for the ageing of organic-coated aqueous aerosols. The surfactant molecules chosen for this study are oleic acid (OA), palmitoleic acid (POA), methyl oleate (MO) and stearic acid (SA) to investigate the effects of chain length, head group and degree of unsaturation on the reaction kinetics and products formed. Fully and partially deuterated surfactants were studied using neutron reflectometry (NR) to determine the reaction kinetics of organic monolayers with NO3 at the air–water interface for the first time. Kinetic modelling allowed us to determine the rate coefficients for the oxidation of OA, POA and MO monolayers to be (2.8±0.7) × 10−8, (2.4±0.5) × 10−8and (3.3±0.6) × 10−8 cm2 molecule−1 s−1 for fitted initial desorption lifetimes of NO3 at the closely packed organic monolayers, τd, NO3, 1, of 8.1±4.0, 16±4.0 and 8.1±3.0 ns, respectively. The approximately doubled desorption lifetime found in the best fit for POA compared to OA and MO is consistent with a more accessible double bond associated with the shorter alkyl chain of POA facilitating initial NO3 attack at the double bond in a closely packed monolayer. The corresponding uptake coefficients for OA, POA and MO were found to be (2.1±0.5) × 10−3, (1.7±0.3) × 10−3 and (2.1±0.4) × 10−3, respectively. For the much slower NO3-initiated oxidation of the saturated surfactant SA we estimated a loss rate of approximately (5±1) × 10−12 cm2 molecule−1 s−1, which we consider to be an upper limit for the reactive loss, and estimated an uptake coefficient of ca. (5±1) × 10−7. Our investigations demonstrate that NO3 will contribute substantially to the processing of unsaturated surfactants at the air–water interface during nighttime given its reactivity is ca. 2 orders of magnitude higher than that of O3. Furthermore, the relative contributions of NO3 and O3 to the oxidative losses vary massively between species that are closely related in structure: NO3 reacts ca. 400 times faster than O3 with the common model surfactant oleic acid, but only ca. 60 times faster with its methyl ester MO. It is therefore necessary to perform a case-by-case assessment of the relative contributions of the different degradation routes for any specific surfactant. The overall impact of NO3 on the fate of saturated surfactants is slightly less clear given the lack of prior kinetic data for comparison, but NO3 is likely to contribute significantly to the loss of saturated species and dominate their loss during nighttime. The retention of the organic character at the air–water interface differs fundamentally between the different surfactant species: the fatty acids studied (OA and POA) form products with a yield of  ∼ 20 % that are stable at the interface while NO3-initiated oxidation of the methyl ester MO rapidly and effectively removes the organic character ( ≤ 3 % surface-active products). The film-forming potential of reaction products in real aerosol is thus likely to depend on the relative proportions of saturated and unsaturated surfactants as well as the head group properties. Atmospheric lifetimes of unsaturated species are much longer than those determined with respect to their reactions at the air–water interface, so they must be protected from oxidative attack, for example, by incorporation into a complex aerosol matrix or in mixed surface films with yet unexplored kinetic behaviour.

Structural Homogeneity in Unsaturated Fatty Acids of Marine Lipids. A Review

1964 ◽  
Vol 21 (2) ◽  
pp. 247-254 ◽  
Author(s):  
R. G. Ackman
Keyword(s):  
Fatty Acids ◽  
Double Bond ◽  
Polyunsaturated Fatty Acids ◽  
Chain Length ◽  
Unsaturated Fatty Acids ◽  
Analytical Data ◽  
Double Bonds ◽  
Marine Origin ◽  
Methyl Group ◽  
Marine Lipids

Consideration of recent analytical data supports the conclusion that the longer-chain polyunsaturated fatty acids of marine origin are all structurally homogeneous in that the double bonds are cis, the double bonds methylene interrupted, and that, with the exception of the C16 chain length, the ultimate double bond will normally be three, six or nine carbon atoms removed from the terminal methyl group.

Diels-Alder Reaction Curing of Chlorobutyl Rubber by bis-Maleimides

1989 ◽  
Vol 62 (1) ◽  
pp. 42-54 ◽  
Author(s):  
K. Ho ◽  
R. Steevensz
Keyword(s):  
Zinc Oxide ◽  
Double Bond ◽  
Chain Length ◽  
Crosslinking Agent ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Electronic Distribution ◽  
Curing Agents ◽  
Chlorobutyl Rubber

Abstract Different bis-maleimides are found to have different efficiencies and reactivities in the crosslinking of CIIR in the presence of zinc oxide. Although the degrees of crosslinking of CIIR by bis-maleimides cannot be defined absolutely, some trends concerning the efficiencies of the crosslinking are evident. In general, the aromatic bis-maleimides gave higher degrees of crosslinking than the aliphatic analogs. The reactivity and crosslinking efficiency of an individual bis-maleimide is very much affected by its end-to-end chain length and its electronic distribution, resulting from the interaction between the maleimide groups, and from the interaction between the maleimide groups and other functional groups present in the same molecule. The longer the bis-maleimide molecule and the more electron deficient the maleimido double bond, the greater its effectiveness as a crosslinking agent. Other curing mechanisms, possibly including polymerization of the maleimido groups, appear to be operative when using aromatic bis-maleimides as curing agents for CIIR.

scholarly journals Single-chain polybutadiene organometallic nanoparticles: an experimental and theoretical study

2016 ◽  
Vol 7 (3) ◽  
pp. 1773-1778 ◽  
Author(s):  
Inbal Berkovich ◽  
Sudheendran Mavila ◽  
Olga Iliashevsky ◽  
Sebastian Kozuch ◽  
N. Gabriel Lemcoff
Keyword(s):  
Molecular Weight ◽  
Double Bond ◽  
High Molecular Weight ◽  
Metal Binding ◽  
Theoretical Study ◽  
Binding Kinetics ◽  
Rhodium Complexes ◽  
Single Chain ◽  
Double Bond Content

High molecular weight polybutadienes and rhodium complexes were used to produce single chain organometallic nanoparticles. A relationship was found between the cis double bond content of the polymer and metal binding kinetics.

The Vulcanization of Highly Elastic Polymers. 81. Sulfur Vulcanization of Ethylene-Propylene Terpolymers Containing Varying Amounts of Double Bonds

1975 ◽  
Vol 48 (5) ◽  
pp. 889-895
Author(s):  
W. Scheele ◽  
S. Fleige
Keyword(s):  
Double Bond ◽  
Supermolecular Structure ◽  
Stoichiometric Ratio ◽  
Technological Properties ◽  
Sulfur Concentration ◽  
Double Bonds ◽  
Ethylene Propylene ◽  
Rate Laws ◽  
Chemical Constitution ◽  
Double Bond Content

Abstract The results of unaccelerated and accelerated vulcanizations of ethylene-propylene terpolymers (EPDM) demonstrate that the reaction of sulfur with allyl systems (such as those which the 1,5-polyenes contain at concentrations far exceeding the quantity of sulfur introduced for crosslinking purposes) tends toward an order above unity and eventually towards second order, as the sulfur concentration and the double bond content approach the stoichiometric ratio. This could be shown with unaccelerated vulcanizations of EPDM in the absence of ZnO, as well as those accelerated by zinc mercaptobenzothiazole. This is so, in our opinion, because in the one case autocatalysis by the polysulfidic sulfur is inhibited, and in the other it becomes negligible because of the very rapid reaction rate. According to Scheele and Huischen, the reaction order for sulfur decrease for the unaccelerated vulcanization of nitrile rubber is first order, both with respect to time and (very important!) with respect to concentration (nt=no=1), and the reaction is not subject to autocatalysis because of disulfidic crosslinks. Accordingly, we arrive at the conviction, in view of the relations obtained with the EPDM rubbers, that all the rate laws determined for sulfur decrease in 1,5-polyene vulcanizations with an excess of double bonds have as their basis pseudo-reaction orders or pseudo-molecularities. In spite of these generally revealing differences in the kinetics of sulfur decrease and in its chemistry between the 1,5-polyenes with their excess of double bonds and the EPDM rubbers with double bond content that is commensurate with the sulfur concentration, the fact still remains that the reaction of sulfur with polymers containing allyl groups has all the characteristics of a multistep reaction of of catalysis by an intermediate and that these characteristics are obviously those generally found in reactions between sulfur and any kind of compound that contains allyl groups. Even the great differences observed between the chemical constitution and the macromolecular structure of the various homo- and copolymers of the 1,3-dienes (natural rubber and poly butadiene), of polypentenamer, and of the EPDM rubbers under consideration here, cannot alter that circumstance, since each situation involves an analogous reaction of sulfur with the allyl units which sulfur-crosslinkable rubbers contain. Any quantitative differences noted can be attributed to the concentration ratios of all the participating reactants as well as the chemical constitution and reactivity of the allyl units. Thus one cannot escape the conclusion that the submolecular, molecular, and supermolecular structure of the rubbers, as well as the polymerization degree and the molecular weight distribution, are of greater importance for the physical, mechanical, and technological properties of the vulcanizates than the vulcanization itself, which, incidentally, should always be carried out so as to realize optimum technological properties in order to meet the industrial technological requirements.

scholarly journals Influence of chain length of pyrene fatty acids on their uptake and metabolism by Epstein–Barr-virus-transformed lymphoid cell lines from a patient with multisystemic lipid storage myopathy and from control subjects

1990 ◽  
Vol 269 (1) ◽  
pp. 107-113 ◽  
Author(s):  
J Radom ◽  
R Salvayre ◽  
T Levade ◽  
L Douste-Blazy
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Chain Length ◽  
Cell Lines ◽  
Lymphoid Cell ◽  
Lipid Storage ◽  
Lymphoid Cells ◽  
Lipid Storage Myopathy ◽  
Fatty Acid Chain ◽  
Lymphoid Cell Lines

The uptake and intracellular metabolism of 4-(1-pyrene)butanoic acid (P4), 10-(1-pyrene)decanoic acid (P10) and 12-(1-pyrene)dodecanoic acid (P12) were investigated in cultured lymphoid cell lines from normal individuals and from a patient with multisystemic lipid storage myopathy (MLSM). The cellular uptake was shown to be dependent on the fatty-acid chain length, but no significant difference in the uptake of pyrene fatty acids was observed between MLSM and control lymphoid cells. After incubation for 1 h the distribution of fluorescent fatty acids taken up by the lymphoid cell lines also differed with the chain length, most of the fluorescence being associated with phospholipid and triacylglycerols. In contrast with P10 and P12, P4 was not incorporated into neutral lipids. When the cells were incubated for 24 h with the pyrene fatty acids, the amount of fluorescent lipids synthesized by the cells was proportional to the fatty acid concentration in the culture medium. After a 24 h incubation in the presence of P10 or P12, at any concentration, the fluorescent triacylglycerol content of MLSM cells was 2-5-fold higher than that of control cells. Concentrations of pyrene fatty acids higher than 40 microM seemed to be more toxic for mutant cells than for control cells. This cytotoxicity was dependent on the fluorescent-fatty-acid chain length (P12 greater than P10 greater than P4). Pulse-chase experiments permitted one to demonstrate the defect in the degradation of endogenously biosynthesized triacylglycerols in MLSM cells (residual activity was around 10-25% of controls on the basis of half-lives and initial rates of P10- or P12-labelled-triacylglycerol catabolism); MLSM lymphoid cells exhibited a mild phenotypic expression of the lipid storage (less severe than that observed in fibroblasts). P4 was not utilized in the synthesis of triacylglycerols, and thus did not accumulate in MLSM cells: this suggests that natural short-chain fatty acids might induce a lesser lipid storage in this disease.

Influence of Chain Length and Double Bond on the Aqueous Behavior of Choline Carboxylate Soaps

Langmuir ◽  
2013 ◽  
Vol 29 (8) ◽  
pp. 2506-2519 ◽  
Author(s):  
Doris Rengstl ◽  
Olivier Diat ◽  
Regina Klein ◽  
Werner Kunz
Keyword(s):  
Double Bond ◽  
Chain Length
Sign in / Sign up

Export Citation Format

Share Document