title: Polar solvent effects on tartaric acid binding by aromatic oligoamide foldamer capsules.
abstract: Aromatic oligoamide sequences able to fold into single helical capsules were functionalized with two types of side chains to make them soluble in various solvents such as chloroform, methanol or water and their propensity to recognize tartaric acid was evaluated. The binding affinities to tartaric acid and binding thermodynamics in different media were investigated by variable temperature (1)H NMR and ITC experiments, the two methods giving consistent results. We show that tartaric acid binding mainly rests on enthalpically favourable polar interactions that were found to be sufficiently strong to be effective in the presence of a polar aprotic solvent (DMSO) and even in pure methanol. Binding in water was very weak. The stronger binding interactions were found to be more susceptible to the effect of competitive solvents and compensated by unfavourable entropic effects. Thus, the best host in a less polar medium eventually was found to be the worst host in protic solvents. An interesting case of entropically driven binding was evidenced in methanol.
authors.affiliation: Univ. Bordeaux, CBMN (UMR 5248), Institut Européen de Chimie Biologie, 2 rue Robert Escarpit, 33607 Pessac, France. i.huc@iecb.u-bordeaux.fr y.ferrand@iecb.u-bordeaux.fr and CNRS, CBMN (UMR 5248), Pessac, France.
authors.forename: Nagula
authors.initials: N
authors.lastname: Chandramouli
authors.affiliation: Univ. Bordeaux, CBMN (UMR 5248), Institut Européen de Chimie Biologie, 2 rue Robert Escarpit, 33607 Pessac, France. i.huc@iecb.u-bordeaux.fr y.ferrand@iecb.u-bordeaux.fr and CNRS, CBMN (UMR 5248), Pessac, France and Medicinal and Pharmaceutical Chemistry Department, Pharmaceutical and Drug Industries Research Division, National Research Centre, 12622 Dokki, Giza, Egypt.
authors.forename: Mohammed Farrag
authors.initials: MF
authors.lastname: El-Behairy
authors.affiliation: Univ. Bordeaux, CBMN (UMR 5248), Institut Européen de Chimie Biologie, 2 rue Robert Escarpit, 33607 Pessac, France. i.huc@iecb.u-bordeaux.fr y.ferrand@iecb.u-bordeaux.fr and CNRS, CBMN (UMR 5248), Pessac, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Lautrette
authors.affiliation: Univ. Bordeaux, CBMN (UMR 5248), Institut Européen de Chimie Biologie, 2 rue Robert Escarpit, 33607 Pessac, France. i.huc@iecb.u-bordeaux.fr y.ferrand@iecb.u-bordeaux.fr and CNRS, CBMN (UMR 5248), Pessac, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Ferrand
authors.affiliation: Univ. Bordeaux, CBMN (UMR 5248), Institut Européen de Chimie Biologie, 2 rue Robert Escarpit, 33607 Pessac, France. i.huc@iecb.u-bordeaux.fr y.ferrand@iecb.u-bordeaux.fr and CNRS, CBMN (UMR 5248), Pessac, France.
authors.forename: Ivan
authors.initials: I
authors.lastname: Huc
mesh_terms: D000577:Amides / Q000737:chemistry*; D001665:Binding Sites; D002214:Capsules; D004121:Dimethyl Sulfoxide / Q000737:chemistry*; D019277:Entropy; D000432:Methanol / Q000737:chemistry*; D015394:Molecular Structure; D066244:Proton Magnetic Resonance Spectroscopy; D012997:Solvents / Q000737:chemistry; D013644:Tartrates / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D000577:Amides; D002214:Capsules; D012997:Solvents; D013644:Tartrates; D014867:Water; C029768:tartaric acid; D000432:Methanol; D004121:Dimethyl Sulfoxide