title: Prevalence and mechanism of polyunsaturated aldehydes production in the green tide forming macroalgal genus Ulva (Ulvales, Chlorophyta).
abstract: Lipoxygenase/hydroperoxide lyase mediated transformations convert polyunsaturated fatty acids into various oxylipins. First, lipoxygenases catalyze fatty acid oxidation to fatty acid hydroperoxides. Subsequently, breakdown reactions result in a wide array of metabolites with multiple physiological and ecological functions. These fatty acid transformations are highly diverse in marine algae and play a crucial rule in e.g., signaling, chemical defense, and stress response often mediated through polyunsaturated aldehydes (PUAs). In this study, green tide-forming macroalgae of the genius Ulva (Chlorophyta) were collected at various sampling sites in the lagoon of the Ria Formosa (Portugal) and were surveyed for PUAs. We demonstrated that sea-lettuce like but not tube-like morphotypes produce elevated amounts of volatile C10-polyunsaturated aldehydes (2,4,7-decatrienal and 2,4-decadienal) upon tissue damage. Moreover, morphogenetic and phylogenetic analyses of the collected Ulva species revealed chemotaxonomic significance of the perspective biosynthetic pathways. The aldehydes are derived from omega-3 and omega-6 polyunsaturated fatty acids (PUFA) with 20 or 18 carbon atoms including eicosapentaenoic acid (C20:5 n-3), arachidonic acid (C20:4 n-6), stearidonic acid (C18:4 n-3), and γ-linolenic acid (C18:3 n-6). We present first evidences that lipoxygenase-mediated (11-LOX and 9-LOX) eicosanoid and octadecanoid pathways catalyze the transformation of C20- and C18-polyunsaturated fatty acids into PUAs and concomitantly into short chain hydroxylated fatty acids.
authors.affiliation: Friedrich Schiller University Jena, Institute for Inorganic and Analytical Chemistry, Lessingstr. 8, Jena 07743, Germany.
authors.forename: Taghreed
authors.initials: T
authors.lastname: Alsufyani
authors.affiliation: CCMAR, CIMAR-Laboratório Associado, Faculdade de Ciências e Tecnologia, Universidade do Algarve, Campus Gambelas, Faro 8005-139, Portugal.
authors.forename: Aschwin H
authors.initials: AH
authors.lastname: Engelen
authors.affiliation: CCMAR, CIMAR-Laboratório Associado, Faculdade de Ciências e Tecnologia, Universidade do Algarve, Campus Gambelas, Faro 8005-139, Portugal.
authors.forename: Onno E
authors.initials: OE
authors.lastname: Diekmann
authors.affiliation: Friedrich Schiller University Jena, Institute for Inorganic and Analytical Chemistry, Lessingstr. 8, Jena 07743, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Kuegler
authors.affiliation: Friedrich Schiller University Jena, Institute for Inorganic and Analytical Chemistry, Lessingstr. 8, Jena 07743, Germany. Electronic address: Thomas.Wichard@uni-jena.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wichard
mesh_terms: D000447:Aldehydes / Q000378:metabolism*; D002384:Catalysis; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis*; D008084:Lipoxygenase / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D044445:Ulva / Q000378:metabolism*
chemical_list: D000447:Aldehydes; D005231:Fatty Acids, Unsaturated; D008084:Lipoxygenase
keywords: Biofuel; Decadienal; Green tide; Infochemicals; Oxylipin; Ulva