Oxidized sterols in patients with diabetic heart disease and microwave-mediated stereoselective synthesis of 3-keto cholesterol and cholesterol epoxide, cholesteryl ester epoxides
Date of Award
Master of Science in Applied Chemistry - (M.S.)
Chemical Engineering, Chemistry and Environmental Science
David S. Kristol
Oxidized low density lipoproteins (ox-LDL) may play important role in mediating hypercholesterolemic endothelial dysfunction. The uptake of modified LDL by macrophages to form foam cells has been implicated in the enhancement of atherosclerosis. Recent reports have suggested that when LDL undergoes oxidation in vitro , it is accompanied by a substantial loss of free and esterified cholesterol leading to the formation of oxidation products of cholesterol ( oxysterols). These compounds are present in human atherosclerotic plaques and in human foam cells.
In this regard we have recently studied the plasma sterol composition in diabetic heart patients We have found cholesterol a- and β-epoxides in addition to 7-ketocholesterol and 7a- and β-hydroxycholesterol. In order to characterize the structure and stereochemistry of cholesterol epoxides in diabetic patients, they were chemically synthesized via a rapid and convenient microwave irradiation technique. The structures of these compounds were determined by NMR and a combination of TLC-fast atom bombardment mass spectrometry. FAB-MS for Oxysterols: 5,6-epoxycholesterol, [M+= 402, (M+H+Na)+= 425, (2M+H+Na)+= 827]; 5,6-epoxy cholesteryl palmitate (M+Na)+= 663; 5,6-epoxy 3-ketocholesterol (M+H)+= 401.
Kothavale, Meenakashi N., "Oxidized sterols in patients with diabetic heart disease and microwave-mediated stereoselective synthesis of 3-keto cholesterol and cholesterol epoxide, cholesteryl ester epoxides" (1997). Theses. 1012.