POLYMERIC SORBENTS FOR BILE-ACIDS .2. OLIGOPEPTIDE-CONTAINING RESINS WITH QUATERNARY AMINE GROUPS

Polymeric sorbents for bile acids have been prepared by attaching lysine-containing peptide sequences onto a water-swellable polyamide resin, by solid phase peptide synthesis, and then attaching a terminal N,N-dimethyl glycine residue that was subsequently quaternized. The resins with relatively longer peptide sequences demonstrated a higher binding capacity, on a per active site basis, for bile acids in pH 7.4 aqueous buffer solutions at 200-degrees-C than cholestyramine and colestipol when tested under the same in vitro conditions. In solutions of low ionic strength, they also have a degree of specificity for bile acid anions. The resins have a higher binding affinity for cholic acid than for glycocholic acid, which indicates the importance of the hydrophobic interactions in the binding.