Generation-dependent host-guest interactions: solution states of polyglycerol dendrimers of generations 3 and 4 modulate the localization of a guest molecule.
Host-guest interactions between polyglycerol dendrimers of generations 3 and 4 (PGD-G3 and G4) and 4-amino-3-hydroxynapthalene-2-sulphonic acid (AHSA) were investigated by fluorescence spectroscopy, isothermal titration calorimetry (ITC), and dynamic light scattering (DLS). PGD-G3 molecules were found to form an associated state with an average diameter of 82.7 nm in aqueous solution, in which PGD-G3 provided a much more polar microenvironment than glycerol. PGD-G3 and AHSA interacted attractively, showing a binding constant of 5.3×10(5)  M(-1)  with a 2:1 stoichiometry. On the other hand, AHSA interacted with the periphery of PGD-G4, the majority of which existed as a unimer, forming a less polar microenvironment. The driving force of the interactions for PGD-G3 and -G4 were mainly enthalpically and entropically driven, respectively. The generation-dependent host-guest interactions were described in conjunction with thermodynamic parameters.
Graduate School of Engineering, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan.
Haejoo
H
Lee
Tooru
T
Ooya
D002151:Calorimetry; D050091:Dendrimers / Q000737:chemistry*; D005990:Glycerol / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D009282:Naphthalenesulfonates / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D012996:Solutions; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
C576716:4-amino-3-hydroxynapthalene-2-sulfonic acid; D050091:Dendrimers; D009282:Naphthalenesulfonates; D011108:Polymers; D012996:Solutions; D014867:Water; C043941:polyglycerol; D005990:Glycerol