Prenylated Phenolics that Cause Contact Dermatitis from Glandular Trichomes of Turricula parryi

Abstract

The principal phenolic constituents were isolated from the exudate of the glandular trichomes of Turricula parryi, a California shrub that causes severe contact dermatitis. The phenolic constituents consist of a complex mixture of methoxylated flavones and derivatives of both farnesylhydroquinone and 3-farnesyl-p-hydroxybenzoic acid in which the C-7 methyl of farnesyl is replaced by hydroxymethyl, formyl and carboxyl groups. Elicitors of allergic contact dermatitis were identified with guinea pigs sensitized to the crude exudate. The principal agents of dermatitis were the farnesyihydroquinone derivatives 3 and 6.