Synthesis and complexation properties of an amphiphilic cyclodextrin

Abstract

An ester was prepared from the reaction of: 3-dodec-2-enyldihydrofuran-2,5- dione 1 with β-cyclodextrin giving a compound 2 with an average substitution of 1.2-1.3. This compound self aggregate with a critical aggregation concentration of 1×10-4 M. It associates with indole derivatives; triptamine, 3 melatonine 4 and 3-indolyl acetic acid 5 at pH 7.00. Under these conditions 3 is a cation, 4 is neutral and 5 is an anion, however electrostatic interactions do not seem to be the main driving force for the interaction since the KASS 91, 30 and < 10 M-1 follow the same order of stability than that reported for native β-CD. On the other hand, the KASS of 8-anilinonaphtalen-1-sulfonate (ANS) is about the same as that of β-CD. Using phenolphthalein as indicator, the association equilibrium constant between 2 and β-CD was determined as 2.1×103 M-1.