title: The fragrance chemical beta-caryophyllene-air oxidation and skin sensitization.
abstract: Fragrances are common causes of allergic contact dermatitis. beta-Caryophyllene is a sesquiterpene that is used as a fragrance chemical. Analogous to the monoterpenes R-limonene and linalool, it can be expected to autoxidize when air exposed. The aim of the present study was to investigate the autoxidation of beta-caryophyllene and to evaluate the effect on the contact allergenic activity. beta-Caryophyllene started to oxidize immediately when air exposed and after 5 weeks almost 50% of the original compound was consumed. Caryophyllene oxide was found to be the major oxidation product. Hydroperoxides of beta-caryophyllene could not be detected in the oxidation mixture. Caryophyllene oxide was shown to be an allergen of moderate strength and beta-caryophyllene air exposed for 10 weeks showed a weak sensitizing capacity in the local lymph node assay. The study reveals that the allergenic activity of beta-caryophyllene is affected by autoxidation, but to a lesser extent when compared to R-limonene and linalool. The present findings support our results in clinical studies showing oxidized beta-caryophyllene to be a rather rare sensitizer compared to oxidized R-limonene and linalool.
authors.affiliation: Department of Chemistry, Dermatochemistry and Skin Allergy, Göteborg University, SE-412 96 Göteborg, Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Sköld
authors.forename: Ann-Therese
authors.initials: AT
authors.lastname: Karlberg
authors.forename: Mihaly
authors.initials: M
authors.lastname: Matura
authors.forename: Anna
authors.initials: A
authors.lastname: Börje
mesh_terms: D000388:Air; D000818:Animals; D003877:Dermatitis, Contact / Q000209:etiology* / Q000473:pathology; D005260:Female; D006168:Guinea Pigs; D051379:Mice; D008808:Mice, Inbred CBA; D010084:Oxidation-Reduction; D010476:Perfume / Q000009:adverse effects* / Q000737:chemistry; D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes / Q000009:adverse effects* / Q000737:chemistry
chemical_list: D010476:Perfume; D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes; C024714:caryophyllene