Antifouling Activity of Halogenated Compounds Derived from the Red Alga Sphaerococcus coronopifolius: Potential for the Development of Environmentally Friendly Solutions.

Maxence Quémener,Fanny Aulanier,Yannick Toueix,Antonios M. Makris,Marilyne Fauchon,Efstathia Ioannou,Vassilios Roussis,Stefanos Kikionis,Claire Hellio

doi:10.3390/md20010032

Abstract

Nowadays, biofouling is responsible for enormous economic losses in the maritime sector, and its treatment with conventional antifouling paints is causing significant problems to the environment. Biomimetism and green chemistry approaches are very promising research strategies for the discovery of new antifouling compounds. This study focused on the red alga Sphaerococcus coronopifolius, which is known as a producer of bioactive secondary metabolites. Fifteen compounds, including bromosphaerol (1), were tested against key marine biofoulers (five marine bacteria and three microalgae) and two enzymes associated with the adhesion process in macroalgae and invertebrates. Each metabolite presented antifouling activity against at least one organism/enzyme. This investigation also revealed that two compounds, sphaerococcinol A (4) and 14R-hydroxy-13,14-dihydro-sphaerococcinol A (5), were the most potent compounds without toxicity towards oyster larvae used as non-target organisms. These compounds are of high potential as they are active towards key biofoulers and could be produced by a cultivable alga, a fact that is important from the green chemistry point of view.

Highlights

In the marine environment, all untreated man-made submerged surfaces are colonized by fouling organisms, such as bacteria, algae and invertebrates, including barnacles and mussels [1,2]
The aim of this study was to further investigate the antifouling potential of bromosphaerol (1) and other major metabolites isolated from the red alga S. coronopifolius against prominent marine biofoulers and two enzymes associated with adhesion process in macroalgae and invertebrates
In order to broaden the knowledge on the mode of action and ecological roles of molecules isolated from S. coronopifolius, we studied the epibiosis defense activities of 15 secondary metabolites isolated from this alga (1–15) on biofouling model organisms

Summary

Introduction

All untreated man-made submerged surfaces are colonized by fouling organisms, such as bacteria, algae and invertebrates, including barnacles and mussels [1,2]. This phenomenon is defined as biofouling [3,4]. Many marine organisms have developed the mechanisms to adhere to natural substrates and to artificial surfaces. In the latter case, unwanted colonization leads to deterioration and corrosion of these surfaces, resulting in significant economic losses [1,7]. Biofouling has been the subject of continuous multidisciplinary research, in maritime fields related to transportation (protection of hulls), marine energy (protection of structures), aquaculture (protection of nets and cages), infrastructure (jetties, dinghies, harbors) and water intakes and cooling circuits of thermal power plants [8,9]

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