Investigation of an Allergen Adsorption on Amine- and Acid-Terminated Thiol Layers: Influence on Their Affinity to Specific Antibodies

The two new p-tert-butylcalix[4]arene derivs. described here bear one or two nalidixic acid arms linked to the lower calixarene rim via the quinolone carboxylate moiety. These derivs. were synthesized in order to investigate two important features of mols. conceived as potential antibiotics, namely, metal cation complexation and interfacial properties, and the way in which they interrelate. The properties of the calixarene derivs. were studied in monomol. films spread on pure water and on aq. subphases contg. biol. relevant mono- and divalent metal cations. These systems were examd. via surface pressure and surface elec. potential measurements, polarization modulation IR reflection absorption spectroscopy, and mol. modeling. Mol. modeling shows that important differences exist, first, between the structure and stability of the complexes formed with the two derivs. and, second, between their mono- and dication complexes. Correlating the properties of the monolayers with those of the modeled mols. lets us propose that the derivs. bearing one or two nalidixic pending arms form preferentially inter- and intramol. complexes, resp. The results obtained in this study indicate that a possible biol. role of the nalidixic arms grafted on the calixarene crown may be revealed upon cation complexation.