title: Selective recognition of sulfate ions by tripodal cyclic peptides functionalised with (thio)urea binding sites.
abstract: A tripodal urea and tripodal thiourea with the same cyclic peptide core have been synthesised and their anion binding ability investigated. In CDCl(3), the tripodal urea self-associates whereas the thiourea does not. Neither compound shows self-association in the more polar 10% v/v DMSO-d(6)/CDCl(3). Both compounds bind strongly and selectively to sulfate ions in CDCl(3) and 10% v/v DMSO-d(6)/CDCl(3). This selectivity is attributed to a unique binding mode for sulfate, in which this tetrahedral anion forms nine hydrogen bonds to the receptors, with three of these coming from the amide protons of the cyclic peptide.
authors.affiliation: School of Chemistry (F11), The University of Sydney, 2006 NSW, Australia.
authors.forename: Philip G
authors.initials: PG
authors.lastname: Young
authors.forename: Katrina A
authors.initials: KA
authors.lastname: Jolliffe
mesh_terms: D000838:Anions / Q000737:chemistry; D001665:Binding Sites; D019281:Dimerization; D006860:Hydrogen Bonding; D015394:Molecular Structure; D010456:Peptides, Cyclic / Q000737:chemistry*; D013431:Sulfates / Q000737:chemistry*; D013890:Thiourea / Q000737:chemistry*
chemical_list: D000838:Anions; D010456:Peptides, Cyclic; D013431:Sulfates; D013890:Thiourea