Some Solubnility Characteristics of Cholesteryl Esters

Abstract

Heretofore, ethanol has been the most widely used solvent for the recrystallization of cholesteryl esters. In this study of some solubility characteristics of cholestery1 esters, n-pentanol is shown to be a more effective solvent than ethanol in which to remove impurities and/or crystalline structural defects from cholesteryl esters that can cause additional transitions on initial heating. n-Pentanol is shown to be a regular solvent for cholestetryl esters, whereas ethanol is not. This could be a major reason why n-pentanol is better able to discriminate between compound and impurity than ethanol. Contrary to previous reports, after crystallization from n-pentanol, in contrast to ethanol, cholesteryl acetate and cholesteryl laurate have only one transition on first heating. A detailed study of cholesteryl benzoate recrystallized from n-pentanol has confirmed that there are two transitions, one at 146.0 °C. the secpond at 179.6 °C. The heats of transitions are found to be 14.7 cal./gm. and 0.26 cal./gm. respectively.