Fatty Acid Alkyl Research Articles

Alkylated cellulosic membranes with enhanced albumin affinity: influence of competing proteins.

4-Vinyl pyridine was grafted to the surface of the cellulosic membrane Cuprophan, and subsequently alkylated with both non-fatty acid-like C10 (GVP-C10) and fatty acid-like C16 (GVP-C16) aliphatic chains. In vitro albumin adsorption studies from single and binary protein solutions, as well as from dilute plasma demonstrated a significant enhancement (1.4-3.89 times) of albumin binding to both the GVP-C10 and GVP-C16 surfaces, relative to unmodified Cuprophan. It is speculated that enhanced albumin adsorption to a surface may improve surface thromboresistance. Further, these results suggest that there is no difference between the enhanced albumin adsorption of the fatty acid and nonfatty like alkyl chains, C10 and C16.

Characteristics of Monolayers of Ferrocene Derivatives and Estimation of Electrical Double Layers Formed in Langmuir Films

Abstract In order to estimate the potential difference of the electrical double layer formed in heterogeneous Sensitizer (S)/Electron Donor (D) Langmuir–Blodgett (LB) films, the surface potentials of the constituent monolayers were measured simultaneously with the π–A isotherms. The S monolayer was a mixed [Ru(bpy)3]2+ complex monolayer with a long alkyl fatty acid, while the D monolayer was one of three kinds of ferrocene monolayers with different signs of the hydrophilic head groups and with the same redox potential. The formation of the potential difference between the charged head group of the amphiphile and its counterion at the water-air interface was confirmed; those values were consistent with the electrical double-layer effect on the luminescent lifetime of [Ru(bpy)3]2+ in the S monolayer in contact with the D monolayer.

Substrate and inhibitor specificity of the lactate carrier of human neutrophils.

The substrate and inhibitor specificity of the lactic acid (Lac) transport system of human neutrophils was investigated. The ability of a variety of compounds to inhibit the influx of [14C]lactate, presumably reflecting competition by substrate analogues for binding at the external translocation site, was taken as an index of affinity for the Lac carrier. pH-state techniques were utilized to assess transportability. Results indicate a relatively low order of selectivity, the neutrophil H+(+)lactate- cotransport system demonstrating a broad acceptance of short-chain unsubstituted and substituted alkyl monocarboxylates as well as aromatic monocarboxylates. There was a slight preference for oxo, Cl, and OH substituents over other groups at the two-position of short chain alkyl fatty acids: all were readily transported across the plasma membrane at rates approaching that of L-lactate itself. Aromatic acids were not transported inward by the carrier although these compounds did permeate via simple nonionic diffusion. The neutrophil Lac carrier can be blocked by a number of cyanocinnamate derivatives, the classical inhibitors of monocarboxylate transport in mitochondria, and by dithiol compounds and sulfhydryl-reactive agents. This constellation of biochemical properties is similar to the features that characterize other well described H+(+)lactate- cotransport systems in red blood cells, Ehrlich ascites tumor cells, hepatocytes, and cardiac sarcolemmal vesicles, although significant differences exist when comparisons are made to the Na(+)-dependent lactate transporter of the kidney proximal tubule.

Resonance Raman study on mutant cytochrome P-450 obtained by site-directed mutagenesis

Resonance Raman spectra were observed for the threonine-301 to serine or valine mutant as well as the wild type of rabbit liver microsomal cytochrome P-450 [laurate(ω — 1)-hydroxylase] ( P-450(ω — 1), which were prepared through site-directed mutagenesis. The high-spin marker resonance Raman (RR) bands became similarly stronger for all the P-450s examined in the oxidized form upon addition of laurate, and the RR spectra in the higher frequency region of the oxidized, reduced and CO-adduct forms did not distinctly differ among the P-450s examined. Nevertheless, the Fe CO stretching mode ( ν Fe CO ) of the CO adduct exhibited an upshift for the valine mutant, suggesting positional proximity of Thr-301 to bound CO like Thr-252 of P-450 cam, in agreement with the expectation from the sequence analysis. The ν Fe CO band was shifted to higher frequency upon binding of normal alkyl fatty acids with C 10 or longer alkyl chain but little affected by binding of shorter fatty acids.

Effect of inorganic salt on adsorption of sodium alkyl sulfates and fatty acid sodium salts from aqueous solution onto ion exchange resins

AbstractThe adsorption isotherms of sodium salts of alkyl sulfonic acid and fatty acid with various carbon numbers onto ion exchange resins were measured in the absence and in the presence of sodium chloride in aqueous solutions. In the absence of the inorganic salt, the amount of adsorption remarkably increased with an increase in the length of alkyl groups in the adsorbates. Furthermore, the amount of adsorption apparently decreased with addition of sodium chloride into the solutions and almost reached a constant value at high concentrations of NaCl. This behavior strongly suggested that the electrostatic interaction on the adsorption decreased with increasing salt concentration and that the effect of hydrophobic interaction seems to play an important role on adsorption.

Recent developments of cyclotron produced radionuclides for nuclear cardiology

For over a decade myocardial perfusion imaging with thallium-201, a cyclotron product, has been routinely used in clinical medicine. Recent advances have allowed the efficient production of very high purity (> 99.8%) iodine-123. New metabolically active 123I labeled radiopharmaceuticals, including alkyl and phenyl fatty acids, and norepinephrine analogs, have been developed and are undergoing clinical trials. Fab' fragments of monoclonal antibodies to cardiac myosin have been labeled with indium-111 (111In) and are undergoing clinical evaluation for imaging myocardial infarcts. Monoclonal antibodies to platelets, fibrin, and the thrombolytic agent, tissue plasminogen activator (TPA), have recently been labeled with 111In. Together these developments in radiotracers and instrumentation should have a significant impact on the future of cardiovascular nuclear medicine. This manuscript will discuss developments in single photon emitting radiotracers for myocardial imaging.

Molecular structure of nonionic surfactants in relation to laboratory insecticidal activity.

Nonionic surface-active agents derived from the condensation of ethyleneoxide with alkyl phenols, fatty alcohols, and fatty acids were evaluated for their activity against pupae of the southern house mosquito, Culex pipiens quinquefasciatus Say. Some of the surfactants were more effective than reference insecticides. The most active compounds were members of the alkylphenol-EO (ethyleneoxide) ethers in the following order of decreasing effectiveness: dinonylphenol-EO, tridecylphenol-EO, monononylphenol-EO, and octylphenol-EO. The following were less effective: tridecyl alcohol-EO ethers, fatty acid-EO esters and several reference anionic surfactants. Activity was greatly dependent on length of the ethylene-oxide chain. For example, the optimum chain length for monononyl-EO was in the range of 4–6 moles EO per mole of alkylphenol. Chain lengths of 1 and 20 moles EO were much less effective. In some of the homologous groups, i.e., octylphenol-EO and 1 series of nonylphenol-EO compounds, activity over a wide range of chain length is attributed to the ethoxylation procedure used for these samples, resulting in a mixture of compounds representing a broad spectrum of chain length. However, the highly active dinonylphenol-EO and tridecylphenol-EO compounds were similarly effective over a wide range of EO chain lengths between 4 and 19.5 moles.