title: Light-activated molecular conductivity in the photoreactions of vitamin D3.
abstract: In this theoretical-experimental approach, we show using ab initio calculations behavior consistent with the activation of 7-dehydrocholesterol, provitamin D(3), as an initial reactant toward ultraviolet-activated reactions of vitamin D(3). We find using molecular orbital theory that a conformation between the provitamin and the vitamin shows higher conductance than those of the reactant and product. We also find experimental evidence of this electrical character by directly measuring current-voltage characteristics on irradiated and nonirradiated samples of the provitamin. The activation of the provitamin D(3) is characterized with an increase in current during the irradiation.
authors.affiliation: Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: Norma L
authors.initials: NL
authors.lastname: Rangel
authors.forename: Kristen S
authors.initials: KS
authors.lastname: Williams
authors.forename: Jorge M
authors.initials: JM
authors.lastname: Seminario
mesh_terms: D002762:Cholecalciferol / Q000737:chemistry* / Q000528:radiation effects*; D003684:Dehydrocholesterols / Q000737:chemistry; D004553:Electric Conductivity; D008027:Light; D015394:Molecular Structure; D010777:Photochemistry; D011789:Quantum Theory; D013997:Time Factors
chemical_list: D003684:Dehydrocholesterols; D002762:Cholecalciferol; C016705:7-dehydrocholesterol