Search

Fluorescently-tagged lipids are a powerful tool for investigating the dynamics of lipids in cell biological studies and in biophysical applications. Herein we report the synthesis and the characterization of a new bola amphiphile, PC12, based on a bisimidic perylene moiety: a central perylene unit is symmetrically linked to two aliphatic chains both ending with a quaternary ammonium group. Absorption and fluorescent properties of the newly synthesized compound were investigated in DMSO and in water as a function of concentration and temperature. Further, the entrapment efficiency, the fluorescence behavior in dimyristoyl-sn-glycero-phosphocholine (DMPC) liposomes, and cell uptake on human and murine glioblastoma cell lines were evaluated. When loaded in liposomes, PC12 follows the same destiny of liposomes themselves in the cell cultures: this is an interesting result because PC12 could be used both as an aspecific dye (free form) and as an organelle-specific lipid probe. [ABSTRACT FROM AUTHOR]

The interaction of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin with the chiral gemini surfactants (2R,3R)- and (2S,3S)-2,3-dimethoxy-1,4-bis(N-hexadecyl-N,N-dimethylammonium)butane bromide gives, below the critical micellar concentration, porphyrin/surfactant heteroaggregates of defined stoichiometry, where the dye molecules have a column-packed, H-type arrangement. The results of a CD investigation suggest that the gemini structure controls both the chirality of the porphyrin-surfactant unit and the chiral morphology of H-type aggregates. [ABSTRACT FROM AUTHOR]

Interaction of the racemic helical homo-octapeptide made by the achiral Cα-methyl alanine (Aib) amino acid with a chiral enantiopure micellar aggregate made of N-dodecylproline led to the deracemization of the helical Aib sequence thus allowing us to obtain for the first time the CD signature in water of a 310 helix devoid of the contribution of any chiral amino acid. [ABSTRACT FROM AUTHOR]

Interaction of the racemic helical homo-octapeptide made by the achiral C(α)-methyl alanine (Aib) amino acid with a chiral enantiopure micellar aggregate made of N-dodecylproline led to the deracemization of the helical Aib sequence thus allowing us to obtain for the first time the CD signature in water of a 310 helix devoid of the contribution of any chiral amino acid.

New types of porphyrin derivatives bearing "C-glycoside" moieties, either in 5,10,15,20- or in 5,15-meso-positions, were prepared and fully characterized. The presence of the glycosidic groups imparts to the title macrocycles, besides an amphiphilic character, a clear tendency to form chiral suprastructures upon solvent-driven self-aggregation in different aqueous-organic solvent mixtures. Supra-assembly phenomena, in terms of the size and morphology of the resulting structures, as well as their kinetics of aggregation, were studied by UV-visible, fluorescence, resonance light scattering (RLS), and CD spectroscopy, indicating that the morphology of the aggregates depends strongly on the structure of the porphyrin rings, and on the bulk conditions of aggregation.

The functionalisation of a porphyrin derivative with a chiral functionality results in a selective interaction with chiral micellar aggregates.

The macroscopic morphology of a micelle biomembrane model strongly affects the aggregation state of an included porphyrin derivative.