title: Current progress in isolation and characterization of toxins isolated from Pfiesteria piscicida.
abstract: The isolation and partial purification of toxic substances derived from Pfiesteria piscicida Steidinger & Burkholder extracts is described. Four distinct bioassay systems were used to monitor bioactivity of the P. piscicida extracts, including a high throughput cell cytotoxicity assay and a reporter gene assay as well as assays using brine shrimp and fish. Using these bioassays to guide fractionation, we have isolated two distinct, active fractions from Pfiesteria culture medium and cell mass extracts on the basis of their solubility characteristics. We have identified and characterized a bioactive lipophilic substance from Pfiesteria-derived extracts as di(2-ethylhexyl)phthalate, a commonly used plasticizer. The source of this typically man-made substance has been identified as originating from Instant Ocean (Aquarium Systems, Mentor, OH, USA), a commercially available seawater salt mixture used to prepare our mass culture growth medium. We have developed chromatographic methodology to isolate a bioactive polar compound isolated from extracts of Pfiesteria culture and presently report the characterization of the activity of this substance. The molecular structural analysis of the polar active component(s) using mass spectrometry and nuclear magnetic resonance spectroscopy is currently under way.
authors.affiliation: Marine Biotoxins Program, Center for Coastal Environmental Health and Biomolecular Research, National Oceanic & Atmospheric Administration-National Ocean Service, Charleston, South Carolina 29412, USA. peter.moeller@noaa.gov
authors.forename: P D
authors.initials: PD
authors.lastname: Moeller
authors.forename: S L
authors.initials: SL
authors.lastname: Morton
authors.forename: B A
authors.initials: BA
authors.lastname: Mitchell
authors.forename: S K
authors.initials: SK
authors.lastname: Sivertsen
authors.forename: E R
authors.initials: ER
authors.lastname: Fairey
authors.forename: T M
authors.initials: TM
authors.lastname: Mikulski
authors.forename: H
authors.initials: H
authors.lastname: Glasgow
authors.forename: N J
authors.initials: NJ
authors.lastname: Deamer-Melia
authors.forename: J M
authors.initials: JM
authors.lastname: Burkholder
authors.forename: J S
authors.initials: JS
authors.lastname: Ramsdell
mesh_terms: D000818:Animals; D001156:Artemia; D001681:Biological Assay; D005399:Fishes; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D020045:Pfiesteria piscicida / Q000472:pathogenicity*; D012995:Solubility; D014118:Toxins, Biological / Q000009:adverse effects / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D014118:Toxins, Biological