A study of various cholesteryl alkanoates by a semi-empirical quantum calculation

In order to study electronic and structural properties of a family of chole sterol esters, the cholesteryl alkanoates. we have performed a semi-empiric al quantum calculation. From some previous works, we have generalized the e xistence of three types of configuration obtained for the cholesteryl aceta te to 14 other cholesteryl alkanoates and we have undertaken the calculatio n of the molecular energy for all studied cholesteryl alkanoates. The influ ence of the alkyl chain length on these energies has been studied. Moreover . in order to know the influence of the extension of the alkyl chain on the rotation of the carbonyl group, we have determined the O-28-C-28-O-3-C-3 r otational energy barrier for only 8 cholesteryl alkanoates. (C) 2001 Elsevi er Science B.V. All rights reserved.