title: Calixarene-Mediated Liquid-Membrane Transport of Choline Conjugates.
abstract: A series of supramolecular calixarenes efficiently transport distinct molecular species through a liquid membrane when attached to a receptor-complementary choline handle. Calix-[6]arene hexacarboxylic acid was highly effective at transporting different target molecules against a pH gradient. Both carboxylic- and phosphonic-acid-functionalized calix[4]arenes effect transport without requiring a pH or ion gradient. NMR binding studies, two-phase solvent extraction, and three-phase transport experiments reveal the necessary and subtle parameters to effect the transport of molecules attached to a choline "handle". On the other hand, rescorin[4]arene cavitands, which have similar guest recognition profiles, did not transport guest molecules. These developments reveal new approaches towards attempting synthetic-receptor-mediated selective small-molecule transport in vesicular and cellular systems.
authors.affiliation: Department of Chemistry and Biochemistry, University Long Beach,, 1250 Bellflower Blvd., Long Beach, CA 90840, USA: http://schrammlab.wordpress.com.
authors.forename: Birendra Babu
authors.initials: BB
authors.lastname: Adhikari
authors.affiliation: Department of Chemistry and Biochemistry, University Long Beach,, 1250 Bellflower Blvd., Long Beach, CA 90840, USA: http://schrammlab.wordpress.com.
authors.forename: Ayu
authors.initials: A
authors.lastname: Fujii
authors.affiliation: Department of Chemistry and Biochemistry, University Long Beach,, 1250 Bellflower Blvd., Long Beach, CA 90840, USA: http://schrammlab.wordpress.com.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Schramm
keywords: Calixarenes; Cavitands; Choline conjugates; Host-guest systems; Liquid-membrane transport; Molecular recognition