Bile acids covalently bound to polysaccharides 1. Esters of bile acids with dextran

Bile acids or their conjugates with amino acids were covalently bound to dextran through ester linkage, in the presence of N,N'-dicyclohexylcarbodiimide as coupling reagent. The degree of substitution was influenced by the nature of the solvent used as reaction medium and was about 30-40 mol%, but the water solubility was preserved only until 6 mol%. Viscosimetric measurements performed with aqueous solutions of modified dextrans showed that the hydrophobic interactions between bulky and rigid bile acid side chains occur mainly intramolecularly. The modified polymers displayed characteristic surface-active properties and good foaming ability. (C) 1999 Elsevier Science Ltd. All rights reserved.