title: Chronic actinic dermatitis to sesquiterpene lactones: [2+2] photoreaction toward thymidine of (+) and (-) alpha-methylene-hexahydrobenzofuranone with a cis ring junction.
abstract: (+) and (-) alpha-methylene-hexahydrobenzofuranone derivatives with a stereochemically pure cis ring junction were used as models of sesquiterpene lactones to study their photoreactivity toward thymidine. After 313 nm irradiation of a deoxygenated acetone solution of lactone models and thymidine, six [2+2] photoadducts were isolated for each enantiomer and fully characterized by a combination of NMR experiments. A common syn regioselectivity and exo stereoselectivity were observed for photoadducts. This high photoreactivity of alpha-methylene-gamma-butyrolactone ring toward thymidine could be an explanation of the progressive evolution of allergic contact dermatitis toward chronic actinic dermatitis.
authors.affiliation: Laboratoire de Dermatochimie, Institut de Chimie, CNRS et Université de Strasbourg, Strasbourg, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Fuchs
authors.forename: Valérie
authors.initials: V
authors.lastname: Berl
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Lepoittevin
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000737:chemistry; D017449:Dermatitis, Allergic Contact / Q000209:etiology; D006801:Humans; D007783:Lactones / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D010787:Photosensitivity Disorders / Q000139:chemically induced / Q000209:etiology*; D012717:Sesquiterpenes / Q000737:chemistry* / Q000528:radiation effects*; D013936:Thymidine / Q000737:chemistry*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D007783:Lactones; D012717:Sesquiterpenes; C014096:alpha-methylene gamma-butyrolactone; D015107:4-Butyrolactone; D013936:Thymidine