Reactions of singlet oxygen with cholesterol: a computational study

Abstract

Listen

Translate article

Production and subsequent reactions of singlet oxygen are a major problem for the safe storage and transportation of foodstuffs. The reactions of singlet oxygen with cholesterol, a molecule commonly found in cells in vivo and also widely found in foodstuffs, are well known experimentally, with the products of these reactions commonly observed. However, a detailed understanding of the reaction mechanisms and transition states and intermediates involved are less well understood. In the current study, we have employed density functional theory to investigate the nature of the reaction pathways of singlet oxygenand cholesterol, determining the transition states and free energies of reaction. We have identified epoxide-like intermediates in the formation of 5-hydroperoxycholesterol and S-6-hydroperoxycholesterol which may be involved in the formation of 5,6-epoxide derivatives of cholesterol, which are an indicator of liver function. These results have given more detailed insight into the reaction of singlet oxygen with cholesterol.