title: Determination of Lipid Hydroperoxides in Marine Diatoms by the FOX2 Assay.
abstract: Ecologically-relevant marine diatoms produce a plethora of bioactive oxylipins deriving from fatty acid oxidation, including aldehydes, hydroxy-fatty acids, epoxy-hydroxy-fatty acids, and oxo-acids. These secondary metabolites have been related to the negative effect of diatoms on copepod reproduction, causing low hatching success and teratogenesis in the offspring during periods of intense diatom blooms. The common intermediates in the formation of oxylipins are fatty acid hydroperoxides. The quantitative measurement of these intermediates can fundamentally contribute to understanding the function and role of lipoxygenase metabolites in diatom-copepod interactions. Here, we describe the successful adaptation of the ferrous oxidation-xylenol orange 2 (FOX2) assay to diatom samples, which showed several advantages over other spectrophotometric and polarographic methods tested in the present work. Using this method we assessed fatty acid hydroperoxide levels in three diatom species: Skeletonema marinoi, Thalassiosira rotula, and Chaetoceros affinis, and discuss results in light of the literature data on their detrimental effects on copepod reproduction.
authors.affiliation: Chemical Ecology Laboratory, Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy. ida.orefice@szn.it.
authors.forename: Ida
authors.initials: I
authors.lastname: Orefice
authors.affiliation: Faculty of Biosciences, Fisheries and Economics, UiT-The Arctic University of Norway, P.O. Box 6050 Langnes, 9037 Tromsø, Norway. andrea.gerecht@uit.no.
authors.forename: Andrea
authors.initials: A
authors.lastname: Gerecht
authors.affiliation: Bio-Organic Chemistry Unit, Institute Biomolecular Chemistry-CNR, Via Campi Flegrei 34, Pozzuoli, 80078 Naples, Italy.
authors.forename: Giuliana
authors.initials: G
authors.lastname: d'Ippolito
authors.affiliation: Bio-Organic Chemistry Unit, Institute Biomolecular Chemistry-CNR, Via Campi Flegrei 34, Pozzuoli, 80078 Naples, Italy. angelo.fontana@icb.cnr.it.
authors.forename: Angelo
authors.initials: A
authors.lastname: Fontana
authors.affiliation: Chemical Ecology Laboratory, Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy. adrianna.ianora@szn.it.
authors.forename: Adrianna
authors.initials: A
authors.lastname: Ianora
authors.affiliation: Chemical Ecology Laboratory, Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy. giovanna.romano@szn.it.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Romano
mesh_terms: D017377:Diatoms / Q000737:chemistry*; D005296:Ferrous Compounds / Q000737:chemistry*; D008054:Lipid Peroxides / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry*; D013454:Sulfoxides / Q000737:chemistry*
chemical_list: D005296:Ferrous Compounds; D008054:Lipid Peroxides; D010636:Phenols; D013454:Sulfoxides; C016833:xylenol orange
keywords: FOX2 assay; diatom detrimental effect; diatoms; fatty acid hydroperoxides; lipoxygenase; oxylipins