Abstract
Various studies on the complexation between crown ethers and biomolecules bearing primary amino groups have been conducted. In the present study, extraction of amino compounds based on the complexation with a crown ether in Li2SO4/PEG aqueous two-phase system has been examined. In the series of crown ethers and their analogues, only dicyclohexano-18-crown-6 (DCH18C6) functioned as a ligand for enhancing the extraction of amino compounds into the PEG-rich phase. The number of primary amino groups of the guest molecules as well as their hydrophobicity is dominant for enhancing the extraction based on the complexation with DCH18C6. From the results of slope analysis, the number of DCH18C6 molecules complexing with an amino compound agreed with the number of primary amino groups.
