28900-95-0Relevant academic research and scientific papers
Chiral discrimination in 1-stearylamine-glycerol monolayers
Vollhardt,Gehlert
, p. 4419 - 4423 (2002)
The effect of the chirality on the thermodynamic behavior, the morphological features, and the 2D crystal structures of 1-stearylamine-glycerol monolayers are studied. The results are based on measurements of the surface pressure-area (??-A) isotherms, fluorescence microscopy, and synchrotron X-ray diffraction at grazing incidence (GIXD). Although the ??-A isotherms of the enantiomeric forms and the racemic mixtures agree largely to each other, the filigree domain patterns show remarkable differences, obviously driven by the chirality. The domains of the R(+) enantiomer are curved clockwise, those of the S(-) enantiomer counterclockwise, whereas those of the racemic mixtures are without a specific sense of direction. Chiral discrimination effects are also found in the lattice structure. The enantiomeric monolayers have an oblique lattice where at compression the tilt direction changes continuously from angles nearly toward NN direction to angles nearly toward NNN direction. The condensed phases of the 1:1 racemic mixtures give rise to rectangular-centered lattices indicating a phase transition accompanied by the change in the tilt direction from NN at 1 mN/m to NNN at 5 mN/m. The filigree domain patterns indicate a comparatively low ordering of the alkyl chains. Correspondingly, a short-range translational order can be concluded from the low position correlation and high tilt angles of the alkyl chains at low surface pressures.
Synthetic ceramides and their use in cosmetic compostions
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, (2008/06/13)
A novel pseudoceramide which has improved dispersibility in aqueous solutions and which can be produced by an economical manufacturing process. The process for producing new pseudoceramides and cosmetic compositions containing the new pseudoceramides are also disclosed.
Liposoluble compounds useful as magnetic resonance imaging agents
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, (2008/06/13)
Novel complexes of paramagnetic ions and compounds bearing long acyl chains have been synthesized as magnetic resonance imaging contrast agents. These novel liposoluble contrast agents may be administered alone, or with lipids, suspending agents or other additives. The lipids may be in the form of liposomes, micelles or lipid emulsions. The contrast agents of the invention have particular use in magnetic resonance imaging of the liver, blood pool and reticuloendothelial system.
