We are studying the reactions of free radicals in lipoproteins and are examining the effects of antioxidants on these processes. The reaction of of organic compounds with molecular oxygen is promoted by free radicals. Polyunsaturated fatty acids and esters are important lipid constituents in biological membranes and in circulating lipid storage proteins, i.e. lipoproteins. The free radical reaction of these lipids with molecular oxygen is a process known as lipid peroxidation, a process that involves intermediate oxygen containing free radicals that attack and abstract hydrogen atoms from lipids, particularly polyunsaturated lipids.
Excessive lipid peroxidation has been implicated in a number of human disorders. In the circulation, the majority of lipids are transported in association with lipoproteins. Oxidation of lipoproteins, and in particular unsaturated fatty acids carried in lipoproteins, is believed to play a key role in the development and/or progression of common diseases including atherosclerosis, neurodegenerative disorders such as Alzheimer's disease, and various automimmune conditions. Antioxidants such as Vitamin E and Vitamin C play critical roles in lipid peroxidation, stopping or inhibiting the critical free radical chain reaction.
We have discovered that one can control stereochemistry in free radical addition reactions to alkenes. Our strategies for stereochemical control in radical addition allow for high levels of selectivity from prochiral radicals or alkenes.
We are currently exploring a new strategy in the control of biological catalysts to modify the structure of of serine protease, such as thrombin and Factor Xa (important enzymes in the blood clotting cascade). Photolysis of themodified enzyme removes the enzyme inhibitor and thus regenerates full enzymatic catalytic capacity.

The group is generally about 15 to 18 members with a 1:2 ratio of postdocs to grad students.

N. A. Porter 
Stevenson Professor
Department of Chemistry
Vanderbilt University
VU Station B, 351822
Nashville, TN 37235
Telephone: (800) 288-5400
Fax: (615) 343-5478