Diversity and Ecology of Marine Algicolous Arthrinium Species as a Source of Bioactive Natural Products

Abstract

In our previous study, all Arthrinium isolates from Sargassum sp. showed high bioactivities, but studies on marine Arthrinium spp. are insufficient. In this study, a phylogenetic analysis of 28 Arthrinium isolates from seaweeds and egg masses of Arctoscopus japonicus was conducted using internal transcribed spacers, nuclear large subunit rDNA, β-tubulin, and translation elongation factor region sequences, and their bioactivities were investigated. They were analyzed as 15 species, and 11 of them were found to be new species. Most of the extracts exhibited radical-scavenging activity, and some showed antifungal activities, tyrosinase inhibition, and quorum sensing inhibition. It was implied that marine algicolous Arthrinium spp. support the regulation of reactive oxygen species in symbiotic algae and protect against pathogens and bacterial biofilm formation. The antioxidant from Arthrinium sp. 10 KUC21332 was separated by bioassay-guided isolation and identified to be gentisyl alcohol, and the antioxidant of Arthrinium saccharicola KUC21221 was identical. These results demonstrate that many unexploited Arthrinium species still exist in marine environments and that they are a great source of bioactive compounds.

Gentisyl Alcohol Inhibits Proliferation and Induces Apoptosis via Mitochondrial Dysfunction and Regulation of MAPK and PI3K/AKT Pathways in Epithelial Ovarian Cancer Cells

“…Particularly, functional compounds possessed by the Arthrinium spp. prevent the formation of bacterial biofilms and oxidative stress by regulating reactive oxygen species [10]. However, the activities of Arthrinium spp.…”

Widespread Existence of Quorum Sensing Inhibitors in Marine Bacteria: Potential Drugs to Combat Pathogens with Novel Strategies

“…Unlike quorum quenching enzymes which were discovered mainly from marine bacteria extracts, small molecule QSIs originated from more diversified sources, including marine animals, algae, sponge, coral, fungi, and bacteria in the broad sense [21,22,23,24,25,26]. Also, certain marine-derived microorganisms were discovered with QS inhibition activity without identification of QS inhibitory substances [27].…”

Marine Microbial Diversity as a Source of Bioactive Natural Products

“…Focusing on marine Arthrinium spp. isolates, Heo et al conducted a phylogenetic analysis based on internal transcribed spacers, nuclear large subunit rDNA, β-tubulin, and translation elongation factor region sequences [9]. The 28 analyzed strains were obtained by cultivation of seaweed tissues (including several Sargassum fulvellum individuals) and Arctoscopus japonicus egg masses.…”

“…The fungus Geosmithia pallida FS140 was isolated from a sediment collected at 2403 m depth in the South China Sea [14]. Twelve diketopiperazines, including the three new thiodiketopiperazines geospallins A-C (6-8), were isolated from this fungus (Figure 1 In the sea, many fungal species are associated with macroscopic organisms [9,11,15]. The isolation of marine fungi from macroorganisms' tissues may in fact be a fairly straightforward way of isolating marine fungi sensu stricto.…”

“…It is interesting to point out that compound 11, which is only produced by the fungus exposed to a metabolite of the plant, was the most active, with MIC values in the 28-57 µ M range. In the sea, many fungal species are associated with macroscopic organisms [9,11,15]. The isolation of marine fungi from macroorganisms' tissues may in fact be a fairly straightforward way of isolating marine fungi sensu stricto.…”