Structure-activity relationships in cholapod anion carriers: enhanced transmembrane chloride transport through substituent tuning.

Chloride transport by a series of steroid-based "cholapod" receptors/carriers was studied in vesicles. The principal method involved preincorporation of the cholapods in the vesicle membranes, and the use of lucigenin fluorescence quenching to detect inward-transported Cl-. The results showed a partial correlation between anion affinity and transport activity, in that changes at the steroidal 7 and 12 positions affected both properties in concert.

Cationic cyclocholamides; toroidal facial amphiphiles with potential for anion transport.

Cholic acid has been transformed into cyclotrimeric and cyclotetrameric toroidal amphiphiles with inward-directed ammonium substituents; the cyclotrimer effects the transport of chloride anions across vesicle bilayer membranes.

Long synthetic nanotubes from calix[4]arenes.

We report the synthesis and encapsulation properties of long (up to 5 nm) molecular nanotubes 1-4, which are based on calix[4]arenes and can be filled with multiple nitrosonium (NO(+)) ions upon reaction with NO(2)/N(2)O(4) gases. These are among the largest nanoscale molecular containers prepared to date and can entrap up to five guests. The structure and properties of tubular complexes 1(NO(+))(2)-4(NO(+))(5) were studied by UV/Vis, FTIR, and (1)H NMR spectroscopy in solution, and also by molecular modeling.

A procedure for filling calixarene nanotubes.

Alkyl nitrites readily transfer nitrosonium into calixarene-based synthetic nanotubes thus offering a mild, effective and precise method to fill them.

Synthesis and lectin binding ability of glycosamino acid-calixarenes exposing GlcNAc clusters.

Novel calix[4 or 8]arene-based glycoconjugates exposing terminal N-acetyl-D-glucosamine clusters have been synthesized using amino acid-calixarenes as building blocks. The obtained glycosamino acid-calixarenes 9b-14b have lectin-binding ability and amplified inhibitory effects on erythrocyte agglutination induced by wheat germ (Triticum vulgaris) agglutinin (WGA). The inhibitory ability is dependent on the presence of the spacer and on the shape and rigidity of the calixarene skeleton.