화학공학소재연구정보센터
Langmuir, Vol.17, No.17, 5319-5323, 2001
Selective removal of palmitic acid from Langmuir monolayers by complexation with new quaternary ammonium beta-cyclodextrin derivatives
The in vivo toxicity of several cyclodextrins (CyDs) appears to involve binding to and extraction of membrane cholesterol, resulting in altered membrane permeability properties. To investigate whether selective binding to lipids other than cholesterol can be achieved, a series of new water-soluble beta -CyD derivatives was synthesized and tested for the ability to extract a fatty acid versus cholesterol in a model system. Quaternary ammonium derivatives (beta -CyD-N+(Me)(2)(CH2)(n)OH OH- (n = 2, 3: compounds 1-2) and beta -CyD-N+(TMe)(2)(CH2)(n)NMe2 OH- (n = 1-3: compounds 3-5)) were 400-600 times more effective than unmodified beta -CyD in inducing desorption of palmitic acid from Langmuir monolayers but were completely ineffective hosts for cholesterol. The rates of desorption of palmitic acid induced by amino- and hydrazine-beta -CyD derivatives [beta -CyD-NH(CH2)(6)NH2 (compound 6) and beta -CyD-NHNH2 (compound 7)] were similar to 100 and 10 times faster, respectively, than that induced by unmodified beta -CyD. A beta -CyD dimer, bis(2,2 ' -S-beta -CyD)di(2-mereaptoethyl) ether (8), and a thioglycerol derivative of beta -CyD, 6-8-(2,3-dihydroxypropyl)thio-beta -CyD (9), were moderately more effective than unmodified beta -CyD in inducing both palmitic acid and cholesterol desorption from their respective pure lipid Langmuir monolayers.