title: In vitro inhibition of 5-lipoxygenase by protolichesterinic acid from Cetraria islandica.
abstract: The aliphatic α-methylene-γ-lactone (+)-protolichesterinic acid (1), isolated from Cetraria islandica, has been shown to exhibit inhibitory effects on the enzyme 5-lipoxygenase in an in vitro assay in which porcine leucocytes are used as a source of the enzyme system. The isomeric compounds (+)-lichesterinic acid (2) and (-)-lichesterinic acid (4), prepared from (+)-protolichesterinic- and (-)-allo-protolichesterinic acids, respectively, exhibited anti-5-lipoxygenase activity of the same order of magnitude. (+)-Methyl lichesterinate (3) was, however, inactive. It was shown that despite its lipophilic nature, protolichesterinic acid is extractable into an aqueous medium, the concentration being dependent on the length of extraction.
authors.affiliation: Dept. of Pharmacy, University of Iceland, 101 Reykjavik, Iceland.
authors.forename: K
authors.initials: K
authors.lastname: Ingolfsdottir
authors.forename: W
authors.initials: W
authors.lastname: Breu
authors.forename: S
authors.initials: S
authors.lastname: Huneck
authors.forename: G A
authors.initials: GA
authors.lastname: Gudjonsdottir
authors.forename: B
authors.initials: B
authors.lastname: Müller-Jakic
authors.forename: H
authors.initials: H
authors.lastname: Wagner