title: Mycosporine-like amino acids in the marine dinoflagellate Gyrodinium dorsum: induction by ultraviolet irradiation.
abstract: Cultures of the marine dinoflagellate Gyrodinium dorsum have been exposed to polychromatic radiation (photosynthetically active radiation and UV) from a solar simulator for up to 72 h. Different irradiance spectra in the ultraviolet are produced by inserting cut-off filters between lamp and samples. The mycosporine-like amino acid (MAA) content and composition are investigated by spectroscopic and chromatographic analysis. The study reveals that G. dorsum contains a complex mixture of several aminocyclohexenimine-MAAs and one aminocyclohexenone-MAA. UV irradiation around 320 nm induces an increase in the concentration of all MAAs in the samples. In contrast, exposure to short-wavelength UV-B radiation results in decreased overall MAA production. Furthermore, there is a spectral shift in the absorption of the MAA mixture towards shorter wavelengths, indicating that short-wavelength UV-B induces an altered MAA composition. The amount of MAAs is normalized to the chlorophyll a concentration.
authors.affiliation: Institut für Botanik und Pharmazeutische Biologie, Friedrich-Alexander-Universität, Erlangen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Klisch
authors.forename: D P
authors.initials: DP
authors.lastname: Häder
mesh_terms: D000596:Amino Acids / Q000096:biosynthesis* / Q000528:radiation effects; D000818:Animals; D003022:Clotrimazole / Q000031:analogs & derivatives* / Q000378:metabolism / Q000528:radiation effects; D004141:Dinoflagellida / Q000378:metabolism / Q000528:radiation effects*; D012623:Seawater; D013472:Sunlight; D014466:Ultraviolet Rays
chemical_list: D000596:Amino Acids; D003022:Clotrimazole