Dendritic folate rosettes as ion channels in lipid bilayers.

The self-assembly of folate dendrimers into pi-stacked supramolecular rosettes is shown to produce ion channels in planar and spherical lipid bilayer membranes. The found ion channels are small, quite homogeneous, long-lived, ohmic, cation selective (Eisenman I), and blockable by the permeant cation.

Thermotropic liquid-crystalline peptide derivatives: oligo(glutamic acid)s forming hydrogen-bonded columns.

We report on new thermotropic liquid-crystalline oligo(amino acid) derivatives forming columnar structures. These are based on branched oligo(glutamic acid)s and 2-(3,4-dialkyloxyphenyl)ethyl moieties. An oligo(glutamic acid) derivative, alpha,gamma-bis(L-glutamoyl) L-glutamic acid tetra[2-(3,4-dioctadecyloxyphenyl)ethyl]ester, shows a hexagonal columnar phase, whilst a glutamic acid derivative, alpha,gamma-bis[2-(3,4-dioctadecyloxyphenyl)ethyl] L-glutamate, does not show a mesophase.

Self-assembly of folic acid derivatives: induction of supramolecular chirality by hierarchical chiral structures.

Hierarchical chiral structures made up of dendritic oligo(L- or D-glutamic acid) moieties of folic acid derivatives induce supramolecular chirality in the self-assembled columnar structures of the folic acids. These folic acids self-assemble through the intermolecular hydrogen bonds of the pterin rings to form disklike tetramers. In the neat states, the stacked tetramers form thermotropic hexagonal columnar phases over wide temperature ranges, including room temperature.