MCM-48 Supported Tungstophosphoric Acid:  An Efficient Catalyst for the Esterification of Long-Chain Fatty Acids and Alcohols in Supercritical Carbon Dioxide

2008 ◽  
Vol 47 (8) ◽  
pp. 2538-2544 ◽  
Author(s):  
Ayyamperumal Sakthivel ◽  
Kenichi Komura ◽  
Yoshihiro Sugi
Keyword(s):  
Carbon Dioxide ◽  
Fatty Acids ◽  
Supercritical Carbon Dioxide ◽  
Tungstophosphoric Acid ◽  
Long Chain Fatty Acids ◽  
Efficient Catalyst ◽  
Long Chain ◽  
Fatty Acids And Alcohols ◽  
Chain Fatty Acids ◽  
Supercritical Carbon

Permeation of long-chain fatty acids and alcohols in rat intestine.

1979 ◽  
Vol 236 (6) ◽  
pp. E721
Author(s):  
V L Sallee
Keyword(s):  
Fatty Acids ◽  
Bile Salt ◽  
Saturated Fatty Acids ◽  
Long Chain Fatty Acids ◽  
Salt Solutions ◽  
Lipid Concentration ◽  
Uptake Rates ◽  
Long Chain ◽  
Fatty Acids And Alcohols ◽  
Chain Fatty Acids

Uptake of long-chain fatty acids and alcohols from micellar bile salt solutions has been studied with everted sacs of rat jejunum. These unidirectional uptake rates are linearly related to lipid concentration if bile salt concentration is constant, but are essentially independent of lipid concentration over a 2.5-fold concentration range if lipid and bile salt concentrations are maintained at a constant ratio. Uptake of lipid from various micellar bile salt solutions was directly related to the experimentally varied monomer activity of solute, thus allowing conversion of uptake rates to permeation coefficients. Natural logarithm of permeation coefficients (ln P) increased linearly for saturated fatty acids of 12--18 carbons, equivalent to an incremental free energy of -695 cal.mol-1 per --CH2--. Alcohols of 10- to 14-carbon chain lengths had a similar relationship on ln P to number of carbons. Previously determined permeation coefficients for fatty acids of 2--10 carbons are now seen to be a nonlinear portion of the curve for ln P versus chain length for all saturated fatty acids.

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