Complex, Dynamic Behavior of Extremely Asymmetric Di-n-Alkylphosphate-Anion Aggregates, the Long-Chain Effect and the Role of a Limiting Size: Cryo-TEM, SANS, and X-Ray Diffraction Studies.

For extremely asymmetric n-hexyl(n-decyl)phosphate (HDeP), n-hexyl(n-dodecyl)phosphate (HDoP), and n-hexyl(n-cetyl)phosphate (HCeP), the effect of the long-chains on the dynamic behavior of their aggregate structures in water was examined by cryo-TEM imaging, SANS, and X-ray diffraction techniques. The cryo-TEM images demonstrated the complex and dynamic behavior of the aggregates, and its dependence on the length of the long-chain. Application of the one-dimensional aggregate theory to the SANS results led to the conclusion that the existence of a limiting size also depended on the length of the main long-hydrocarbon chain and affected strongly the dynamic behavior of the aggregates, causing breakage of thread-like micelles or ribbon-like aggregates.

The role of an L-leucine residue on the conformations of glycyl-L-leucine oligomers and its N- or C-terminal dependence: infrared absorption and Raman scattering studies.

The conformations of glycyl-L-leucine oligomers (GnL, residue number n = 3, 4, and 5) in the solid state were found to be similar to that of a polyglycine II (PGII). However, for L-leucyl-glycine oligomers (LGn; n = 3, 4, 5) in the solid state, LG3 and LG4 have already been confirmed to take a reverse-turn structure (LG3-type reverse-turn) while LG5 adopts a PGII-type helix. The present results provide evidence that the conformations of L-leucine-containing glycine oligomers depend strongly upon whether the L-leucine residue is placed in the N- or C-terminal position.

Aggregate structures of asymmetric di-alkyl phosphate anions and the role of conformations about the polar region: SANS, cryo-TEM, Raman scattering, 13C NMR, and selective NOE studies.

The aggregate structures of two di-n-alkyl-phosphate anions (di-n-alkyl: n-butyl(n-dodecyl)(BDoP) and n-hexyl(n-dodecyl)(HDoP)) in water were studied by the use of SANS, cryo-TEM, Raman scattering, (13)C NMR, and selective NOE ((1)H{(1)H}) techniques. The results of SANS indicated that the different -CH(2)- lengths of the short chain led to a marked difference in the aggregational behavior of BDoP and HDoP. Cryo-TEM added direct images to support the average aggregation size and shape predicted by the SANS analyses.

Concentration-resolved 2D correlation gel permeation chromatography study of aggregate-aggregate interactions in the polymerization products of triethoxysilyl-terminated polystyrene silane-coupling agent.

Concentration-resolved 2D correlation gel permeation chromatography (GPC) has been used to examine the intricate details of the HCl-catalyzed polymerization of a polymeric silane-coupling agent (SCA), triethoxysilyl-terminated polystyrene (TESiPS). The concentration-resolved 2D correlation GPC maps directly reflect the marked difference in the aggregate-aggregate interactions of dilute and concentrated monomeric units, which govern the differences in the polymerized products. There is an optimum concentration of SCA for the enhancement of interfacial strength and subsequent polymerization.

Folded structures of L-leucylglycine oligopeptides and their aggregational behavior in aqueous solution: Raman scattering spectra and proton NMR spin-lattice relaxation studies.

The aggregational behavior of three L-leucylglycine oligopeptides (residue numbers of glycine are 3, 4, and 5) in aqueous solution was investigated by the use of Raman scattering and 1H NMR spin-lattice relaxation methods. The results indicate that their oligopeptides take up a folded structure to form dimeric aggregates above their critical aggregation concentration. The application of one-dimensional aggregate theory to these systems provides the following prediction.

Effect of apple cell walls and their extracts on the activity of dietary antioxidants.

The effect of dietary fiber in the form of apple cell walls and pectin extracts on natural antioxidants was examined. Cell walls (CW), isolated from apples ( Malus domestica Borkh. cv.

The products from lipase-catalysed hydrolysis of bovine milkfat kill Helicobacter pylori in vitro.

Free fatty acids and monoglycerides released from milkfat by partial pregastric lipase-catalysed hydrolysis are bactericidal towards Helicobacter pylori. Two milkfat preparations were investigated: a normal bovine milkfat, and a fractionated milkfat preparation, termed ModFat, enriched in triglycerides containing short- and medium-chain fatty acids. The released products were tested for bactericidal potency against H.

Application of emulsifiers/stabilizers in dairy products of high rheology.

The role played by low molecular weight emulsifiers (mono- and di-glycerides) and non-dairy stabilizers (alginates, carrageenans, gums and gelatins) in the formation and stabilization of liquid milk (and specifically a functionalized milk containing omega-3), yoghurt and ice cream has been reviewed. Attention is given to the interactions that may occur between the reactive sites on polysaccharide stabilizers and milk proteins and other milk components, and to the desirable characteristics, e.g.

Antibacterial actions of fatty acids and monoglycerides against Helicobacter pylori.

The bactericidal potencies of saturated and unsaturated fatty acids (FAs) and monoglycerides (MGs) against Helicobacter pylori were determined following short incubations with freshly harvested cells over a range of pHs. FAs and their derivatives with an equivalent-carbon number of 12 were the most potent: lauric acid had a minimum bactericidal concentration (MBC) at pH 7.4 of 1 mM, myristoleic and linolenic acid were the most potent unsaturated FAs (MBCs of 0.

Fourier transform IR study of aggregational behavior of N-acetyl-L- and N-butyloxycarbonyl-L-glutamic acid oligomeric benzyl esters in dioxane and benzene: beta-turn --> antiparallel beta-sheet transition.

Oligomeric N-acetyl-L-glutamic acid benzyl esters (AN(p)Z) with exact residue numbers (N(p) = 2, 3, 4, and 5) and N-butyloxycarbonyl-L-glutamic acid benzyl esters (BOCN(p)Z) with exact residue numbers (N(p) = 4, 5, 6, and 8) are synthesized by a stepwise procedure in a liquid phase. The aggregational behavior of these oligomeric molecules in dioxane and benzene is examined by Fourier transform IR spectra. In particular, the concentration dependence of the IR spectra for the AN(p)Z solutions with N(p) values of 4 (A4Z) and 5 (A5Z) shows that the predominant antiparallel beta-sheet structure is stabilized above the critical aggregation concentration (cac), while other conformations including beta-turns may coexist below the cac.

The antimicrobial properties of milkfat after partial hydrolysis by calf pregastric lipase.

Studies on the kinetic characteristics of calf pregastric lipase (EC 3.1.1.

Early weaning of calves using feedstuffs. A rationalization based on inhibition of lipolysis.

The ability of broll (a combination of the wheat-milling byproducts bran and pollard, i.e., a mixture of wheat bran, husk, and flour) and blackstrap molasses (an ingredient of calf feed) to inhibit calf pregastric lipase (CPGL)-catalyzed hydrolysis of tributyrylglycerol (TBG) has been studied in vitro.