title: Chemical, molecular, and eco-toxicological investigation of Ostreopsis sp. from Cyprus Island: structural insights into four new ovatoxins by LC-HRMS/MS.
abstract: Blooms of benthic dinoflagellates of the genus Ostreopsis (mainly O. cf. ovata and occasionally O. cf. siamensis) represent a serious concern for humans in the Mediterranean area, due to production of palytoxin-like compounds listed among the most potent marine toxins known. In this work, six strains of Ostreopsis sp. from Cyprus Island were analyzed through an integrated approach based on molecular, chemical, and eco-toxicological methods. Cypriot Ostreopsis sp. was found to be a species distinct from O. cf. ovata and O. cf. siamensis, belonging to the Atlantic/Mediterranean Ostreopsis spp. clade. Some variability in toxin profiles emerged: three strains produced ovatoxin-a (OVTX-a), OVTX-d, OVTX-e, and isobaric palytoxin, so far found only in O. cf. ovata; the other three strains produced only new palytoxin-like compounds, which we named ovatoxin-i, ovatoxin-j1, ovatoxin-j2, and ovatoxin-k. The new ovatoxins present the same carbon skeleton as ovatoxin-a, differing primarily in an additional C2H2O2 moiety and an unsaturation in the region C49-C52. Other minor structural differences were found, including the presence of a hydroxyl group at C44 (in OVTX-j1 and OVTX-k) and the lack of a hydroxyl group in the region C53-C78 (in OVTX-i and OVTX-j1). The toxin content of the analyzed Ostreopsis sp. strains was in the range 0.06-2.8 pg cell(-1), definitely lower than that of a Ligurian O. cf. ovata strain cultured under the same conditions. Accordingly, an eco-toxicological test on Artemia salina nauplii demonstrated that Ostreopsis sp. presents a very low toxicity compared to O. cf. ovata. The whole of these data suggest that Ostreopsis sp. from Cyprus Island poses a relatively low risk to humans.
authors.affiliation: Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131, Naples, Italy.
authors.forename: Luciana
authors.initials: L
authors.lastname: Tartaglione
authors.affiliation: Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131, Naples, Italy.
authors.forename: Antonia
authors.initials: A
authors.lastname: Mazzeo
authors.affiliation: Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131, Naples, Italy. dellaver@unina.it.
authors.forename: Carmela
authors.initials: C
authors.lastname: Dell'Aversano
authors.affiliation: Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131, Naples, Italy.
authors.forename: Martino
authors.initials: M
authors.lastname: Forino
authors.affiliation: DISTAV, University of Genoa, Corso Europa 26, 16132, Genoa, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Giussani
authors.affiliation: DISB, University of Urbino, Viale Trieste 296, 61121, Pesaro, Italy.
authors.forename: Samuela
authors.initials: S
authors.lastname: Capellacci
authors.affiliation: DISB, University of Urbino, Viale Trieste 296, 61121, Pesaro, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Penna
authors.affiliation: DISTAV, University of Genoa, Corso Europa 26, 16132, Genoa, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Asnaghi
authors.affiliation: CNR, Institute of Marine Sciences (ISMAR), Via De Marini 6, 16149, Genoa, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Faimali
authors.affiliation: DISTAV, University of Genoa, Corso Europa 26, 16132, Genoa, Italy.
authors.forename: Mariachiara
authors.initials: M
authors.lastname: Chiantore
authors.affiliation: Tama Laboratory, Japan Food Research Laboratories, 6-11-10 Nagayama, Tama-shi, Tokyo, 206-0025, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yasumoto
authors.affiliation: Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131, Naples, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Ciminiello
mesh_terms: D000818:Animals; D001156:Artemia / Q000187:drug effects; D002853:Chromatography, Liquid; D004141:Dinoflagellida / Q000737:chemistry* / Q000145:classification / Q000378:metabolism; D062312:Islands; D008387:Marine Toxins / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity*; D013058:Mass Spectrometry; D015394:Molecular Structure
chemical_list: D008387:Marine Toxins
keywords: Cyprus Island; LC-HRMS/MS; Ostreopsis sp.; Ovatoxins