1.D.120. The Transmembrane Bis-cholic Acid Derivative (BCAD) Family
Bischolic acid derivative 1 linked by m-xylylene dicarbamate at the 3,3'-position was synthesized, and the single ion channel properties were examined (Yoshii et al. 2004). Compound 1 showed two clearly distinct conductances, 9.5 (type A) and 25.3 pS (type B), under 500 mM KCl symmetric salt conditions, whereas various conductances, ranging from 5-20 pS, were observed in the tetramethylether analogue. Results indicated that the replacement of four methylether groups with hydroxyls at the 7, 7', 12, and 12' positions in the bischolic acid framework influences the stability of aggregated (supramolecular) ion channel structures. Ion permeability ratios (potassium/chloride and potassium/sodium) for each type of channel were also determined (Yoshii et al. 2004).