title: Cyclization of peptoids by formation of boronate esters.
abstract: Introduction of conformational constraints into peptoids (N-substituted oligoglycines) will enable new applications in molecular recognition and self-assembly. Peptoids that contain both a phenylboronic acid side chain and a vicinal diol cyclize by intramolecular condensation to form boronate esters. A fluorescent indicator of free boronic acid was used to assay esterification. A galactose moiety 2 to 5 monomer units away from a boronic acid side chain in a peptoid reacts with the boronic acid in competition with the indicator. The intramolecular reaction predominates in each case, with 80-90% of the peptoid cyclized. When the diol is a simple 2,3-dihydroxypropyl group, esterification is less favored but still appreciable.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, Texas, 75390-8573 USA.
authors.forename: Sara
authors.initials: S
authors.lastname: Chirayil
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Luebke