| Abstract
| - As a new class of host for both specific proteins and hydrophobic molecular guests, cyclophane-basedresorcinarene oligomers were designed on the basis of a molecular design that allows the assembly offour or 12 anionic resorcinarenes on a cyclophane skeleton. We prepared a cyclophane-based resorcinarenetetramer (4), constructed with a tetraaza[6.1.6.1]-paracyclophane skeleton and four resorcinarenes bearingheptacarboxylic acid residues that connect to the macrocycle through amide linkages. In addition, weprepared an extended analogical dodecamer (12), which was constructed with a pentakis(cyclophane)skeleton and 12 resorcinarenes. The cyclophane-based resorcinarene oligomers exhibited potent recognitioncapabilities toward histone, a small basic protein of eukaryotic chromatins. The binding constants (K) ofcyclophane-based resorcinarene tetramer 4 and dodecamer 12 with histone were determined to be 1.3 ×107 and 8.4 × 107 M-1, respectively, by means of surface plasmon resonance measurements. The Kvalues of 4 and 12 with histone were 31- and 200-fold larger than that of an untethered referenceresorcinarene, reflecting the multivalency effects in resorcinarenes. In addition to that, cyclophane-basedresorcinarene tetramer 4 and dodecamer 12 captured hydrophobic guests such as 6-p-toluidinonaphthalene-2-sulfonate, with respective binding constants of 2.4 × 103 and 2.5 × 104 M-1 in an aqueous HEPESbuffer as evaluated by fluorescence spectroscopy. Furthermore, the resorcinarene oligomers were alsofound to act as guest carriers from the bulk aqueous phase to histone surfaces, as confirmed by fluorescencespectroscopy.
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