title: Vitamin E Circular Dichroism Studies: Insights into Conformational Changes Induced by the Solvent's Polarity.
abstract: We used circular dichroism (CD) to study differences in CD spectra betweenα-,δ-, and methylated-α-tocopherol in solvents with different polarities. CD spectra of the different tocopherol structures differ from each other in intensity and peak locations, which can be attributed to chromanol substitution and the ability to form hydrogen bonds. In addition, each structure was examined in different polarity solvents using the Reichardt index-a measure of the solvent's ionizing ability, and a direct measurement of solvent-solute interactions. Differences across solvents indicate that hydrogen bonding is a key contributor to CD spectra at 200 nm. These results are a first step in examining the hydrogen bonding abilities of vitamin E in a lipid bilayer.
authors.affiliation: Department of Physics, Brock University, St. Catharines, ON L2S 3A1, Canada. marquardtdt@ornl.gov.|Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, University of Graz, Graz 8010, Austria. marquardtdt@ornl.gov.|BioTechMed-Graz, Graz 8010, Austria. marquardtdt@ornl.gov.
authors.forename: Drew
authors.initials: D
authors.lastname: Marquardt
authors.affiliation: Department of Physics, Brock University, St. Catharines, ON L2S 3A1, Canada. brad.van.oosten2@brocku.ca.
authors.forename: Brad J
authors.initials: BJ
authors.lastname: Van Oosten
authors.affiliation: Department of Chemistry, Brock University, St. Catharines, ON L2S 3A1, Canada. mikel.ghelfi2@brocku.ca.
authors.forename: Mikel
authors.initials: M
authors.lastname: Ghelfi
authors.affiliation: Department of Chemistry, Brock University, St. Catharines, ON L2S 3A1, Canada. jatkinson@brocku.ca.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Atkinson
authors.affiliation: Department of Physics, Brock University, St. Catharines, ON L2S 3A1, Canada. thad.harroun@brocku.ca.
authors.forename: Thad A
authors.initials: TA
authors.lastname: Harroun
keywords: Vitamin E; circular dichroism; methylated tocopherol; reichardt’s dye; α-tocopherol; δ-tocopherol