title: A thermodynamic insight into the recognition of hydrophilic and hydrophobic amino acids in pure water by aza-scorpiand type receptors.
abstract: Interactions of different hydrophilic (His, Asp, Glu,) and hydrophobic (Ala, Phe, Tyr, Trp) amino acids in water with a scorpiand aza-macrocycle (L1) containing a pyridine group in the ring and its derivative (L2) bearing a naphthalene group in the tail have been analysed by potentiometric and calorimetric measurements. Theoretical calculations corroborate that major attractive forces that hold the adduct together are hydrogen bonds and salt-bridges, even though other interactions such as π-stacking or NH(+)⋯π may contribute in the case of hydrophobic amino acids and L2. Calorimetric measurements indicate that the interactions between L1 and the different amino acids are principally driven by entropy, often associated with solvation/desolvation processes.
authors.affiliation: Instituto de Ciencia Molecular, C/Catedrático José Beltrán 2, 46980 Paterna, Valencia, Spain. enrique.garcia-es@uv.es.
authors.forename: Salvador
authors.initials: S
authors.lastname: Blasco
authors.forename: Begoña
authors.initials: B
authors.lastname: Verdejo
authors.forename: Carla
authors.initials: C
authors.lastname: Bazzicalupi
authors.forename: Antonio
authors.initials: A
authors.lastname: Bianchi
authors.forename: Claudia
authors.initials: C
authors.lastname: Giorgi
authors.forename: Concepción
authors.initials: C
authors.lastname: Soriano
authors.forename: Enrique
authors.initials: E
authors.lastname: García-España
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D002151:Calorimetry; D047248:Crown Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D008958:Models, Molecular; D011199:Potentiometry; D062165:Receptors, Artificial / Q000138:chemical synthesis / Q000737:chemistry*; D012996:Solutions; D013816:Thermodynamics; D014867:Water
chemical_list: D000596:Amino Acids; D047248:Crown Compounds; D062165:Receptors, Artificial; D012996:Solutions; D014867:Water