Occurrence Of Mycosporine-like Amino Acids Research Articles

Argentine squid (Illex argentinus): A source of mycosporine-like amino acids with antioxidant properties

Here we report on the occurrence of mycosporine-like amino acids (MAAs) in the Argentine shortfin squid, Illex argentinus, the second fishery resource mostly exploited in the Argentinean continental shelf. The total content of four MAAs was evaluated by reverse-phase-HPLC in different tissues (eyes, skin, liver, and gonads). Also, the antioxidant activity of crude extracts was assessed by in-vitro determinations: 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), Folin-Ciocalteu, and ferrous ion-chelating capacity assays. The content of MAAs was found to be almost ten times higher in female gonads than in other tissues (11,89 ± 0,56 mg/g dry weight). Extracts from skin, female gonads and eyes, exhibit higher antioxidant activity than the reference compounds ascorbic acid and TROLOX. Overall, Argentine squid waste is a promising potential source of MAAs with antioxidant and UV photoprotective properties, which could bear interest in food, cosmetic and pharmaceutical industries, thus encouraging maximal and sustainable use of fishing resources.

Occurrence of Mycosporine-like Amino Acids (MAAs) from the Bloom-Forming Cyanobacteria Aphanizomenon Strains.

Mycosporine-like amino acids (MAAs) are widespread in various microbes and protect them against harsh environments. Here, four different Aphanizomenon species were isolated from severely eutrophic waterbodies, Lake Dianchi and the Guanqiao fishpond. Morphological characters and molecular phylogenetic analysis verified that the CHAB5919, 5921, and 5926 strains belonged to the Aphanizomenon flos-aquae clade while Guanqiao01 belonged to the Aphanizomenon gracile clade. Full wavelength scanning proved that there was obvious maximal absorption at 334 nm through purified methanol extraction, and these substances were further analyzed by HPLC and UPLC-MS-MS. The results showed that two kinds of MAAs were discovered in the cultured Aphanizomenon strains. One molecular weight was 333.28 and the other was 347.25, and the daughter fragment patterns were in accordance with the previously articles reported shinorine and porphyra-334 ion characters. The concentration of the MAAs was calibrated from semi-prepared MAAs standards from dry cells of Microcystis aeruginosa PCC7806 algal powder, and the purity of shinorine and porphyra-334 were 90.2% and 85.4%, respectively. The average concentrations of shinorine and porphyra-334 were 0.307–0.385 µg/mg and 0.111–0.136 µg/mg in Aphanizomenon flos-aquae species, respectively. And there was only one kind of MAAs (shinorine) in Aphanizomenon gracile species.,with a content of 0.003–0.049 µg/mg dry weight among all Aphanizomenon gracile strains. The shinorine concentration in Aphanizomenon flos-aquae was higher than that in Aphanizomenon gracile strains. The total MAAs production can be ranked as Aphanizomenon flos-aquae > Aphanizomenon gracile.

Sunscreen Effect Exerted by Secondary Carotenoids and Mycosporine-like Amino Acids in the Aeroterrestrial Chlorophyte Coelastrella rubescens under High Light and UV-A Irradiation.

The microalga Coelastrella rubescens dwells in habitats with excessive solar irradiation; consequently, it must accumulate diverse compounds to protect itself. We characterized the array of photoprotective compounds in C. rubescens. Toward this goal, we exposed the cells to high fluxes of visible light and UV-A and analyzed the ability of hydrophilic and hydrophobic extracts from the cells to absorb radiation. Potential light-screening compounds were profiled by thin layer chromatography and UPLC-MS. Coelastrella accumulated diverse carotenoids that absorbed visible light in the blue–green part of the spectrum and mycosporine-like amino acids (MAA) that absorbed the UV-A. It is the first report on the occurrence of MAA in Coelastrella. Two new MAA, named coelastrin A and coelastrin B, were identified. Transmission electron microscopy revealed the development of hydrophobic subcompartments under the high light and UV-A exposition. We also evaluate and discuss sporopollenin-like compounds in the cell wall and autophagy-like processes as the possible reason for the decrease in sunlight absorption by cells, in addition to inducible sunscreen accumulation. The results suggested that C. rubescens NAMSU R1 accumulates a broad range of valuable photoprotective compounds in response to UV-A and visible light irradiation, which indicates this strain as a potential producer for biotechnology.

Mycosporine-like amino acid content in the sea anemones Aulactinia marplatensis, Oulactis muscosa and Anthothoe chilensis

The occurrence of mycosporine-like amino acids (MAAs) in the sea anemones Aulactinia marplatensis (Zamponi, 1977), Oulactis muscosa (Drayton in Dana, 1846) and Anthothoe chilensis (Lesson, 1830), from the rocky intertidal habitats on the coast of Mar del Plata, Argentina, was assessed by HPLC. The pattern of MAAs in the mussel Brachidontes rodriguezi, main component of the diet for A. marplatensis and O. muscosa, was as well determined. The results were comparatively analyzed together and with previously reported MAA content in species mainly of the genus Anthopleura. The correlation between the MAA concentration and light availability of their habitats is in line with the photoprotective role assigned to the compounds. The high proportion of mycosporine-taurine in the three species and the results for the evaluation of MAAs in the mussels point to a non-dietary origin or a regulated biotransformation metabolism of dietary MAAs and/or their precursors that is common to sea anemones.

Mycosporine-like Amino Acids in the Zooxanthella-Ciliate Symbiosis Maristentor dinoferus

Coral reef organisms living in mutualistic symbioses with phototrophic dinoflagellates are widespread in shallow UV-transparent waters. Maristentor dinoferus is a recently discovered species of marine benthic ciliate that hosts symbiotic dinoflagellates of the genus Symbiodinium. In this study, we tested this ciliate for the occurrence of mycosporine-like amino acids, a family of secondary metabolites that minimize damage from exposure to solar UV radiation by direct screening. Using high-performance liquid chromatography and liquid chromatography coupled to mass spectrometry, five mycosporine-like amino acids (shinorine, palythenic acid, palythine, mycosporine-2-glycine, and porphyra-334) were identified in aqueous methanolic extracts of the symbiosis. This is the first report of mycosporine-like amino acids in a marine ciliate.

The occurrence of mycosporine-like amino acids in the gametophytic and sporophytic stages of Bangia (Bangiales, Rhodophyta)

C. Boedeker and U. Karsten. 2005. The occurrence of mycosporine-like amino acids in the gametophytic and sporophytic stages of Bangia (Bangiales, Rhodophyta). Phycologia 44: 403–408.Ultraviolet-absorbing mycosporine-like amino acids (MAAs) were identified and quantified in both the gametophytic and sporophytic life stages of the cosmopolitan intertidal genus Bangia. Field samples were compared with culture material originating from different biogeographic regions, including freshwater populations. All cultures were kept for a long time under low-irradiance conditions prior to MAA analysis. Within all isolates investigated, four distinct compounds were found which were identified as shinorine, porphyra-334, asterina-330 and palythine. Gametophytic filaments always exhibited high concentrations of MAAs, with porphyra-334 being the dominant compound. Field and culture material did not differ in the amount of MAAs, indicating that Bangia does not adjust the amount of sunscreens to environmental conditions. Freshwater isolates contained lower amounts of MAAs compared to marine strains. However, a biogeographical trend in MAA contents reflecting the origin of the samples from habitats with different climate and insolation was not observed. Even the shell-boring sporophytic conchocelis stage contained significant amounts of MAAs, but in lower concentrations than the gametophytes, raising the possibility of MAAs fulfiling different functions in the two life stages.

The occurrence of UV-B absorbing mycosporine-like amino acids in freshwater and terrestrial microalgae (Chlorophyta)

The occurrence of mycosporine-like amino acids (MAAs) in freshwater and terrestrial microalgae and their accumulation in response to UV-B exposure were examined. Three UV-B-resistant species, Enallax coelastroides, Scenedesmus sp. and Scotiella chlorelloidea, and four UV-B-sensitive microalgal species: Ankistrodesmus spiralis, Chlorella minutissima, Chlorella sorokiniana and Pseudococcomyxa sp. were found to contain MAAs. However, Coelastrum microporum did not appear to contain any MAA. A total of seven MAAs was identified among the tested species. Besides five known MAAs: mycosporine-Gly ( λ max = 310 nm), palythine ( λ max = 320 nm), asterina ( λ max = 330 nm), shinorine ( λ max = 334 nm) and porphyra ( λ max = 334 nm), two novel compounds (compound I: λ max = 302 nm, Rt = 2.6 min; compound II: λ max = 292 nm, Rt = 7.3 min) were found in Ch. sorokiniana and Scenedesmus sp. The accumulation of MAAs was induced by both artificial and solar UV-B radiation, which was observed in both the UV-B-resistant and UV-B-sensitive species. No clear correlation between MAA accumulation and UV-B resistance of the photosynthetic apparatus was established. The response of MAA accumulation to UV-B exposure was species-dependent and individual MAA-specific.

Survey of ultraviolet radiation-absorbing mycosporine-like amino acids in organs of coral reef holothuroids

Twelve deposit-feeding species of tropical holothuroid echinoderms (families Holothuriidae and Stichopodidae) were surveyed for the presence of UV-absorbing mycosporine-like amino acids (MAAs) during Austral summer at Hicks Reef, Great Barrier Reef (GBR). An additional species belonging to the Synaptidae was collected in Austral winter from Shrimp Reef, GBR. Tissues of all species contained MAAs, including mycosporine-glycine, shinorine, porphyra-334, mycosporine-2 glycine, palythine, asterina-330 and palythinol. The MAAs in holothuroids occur predominantly in their epidermis, which suggests a photoprotective function, since the highest concentrations of these UVabsorbing compounds would be expected in tissues directly exposed to sunlight. Concentrations of total MAAs in dorsal epidermal tissues ranged from 21.9 nmol mg-' protein (Stichopus variegatus) to 2053 nmol mg-' protein (Pearsonothuria graeffei). Taxonomic, tissue-specific and ecological relationships in the occurrence of MAAs in tropical deposit-feeding holothuroids are discussed.

Occurrence of mycosporine-like amino acids in the red-tide dinoflagellate Alexandrium excavatum: UV-photoprotective compounds?

Occurrence of mycosporine-like amino acids in the red-tide dinoflagellate <i>Alexandrium excavatum</i>: UV-photoprotective compounds?