The Plant Alkaloid Camptothecin as a Novel Antifouling Compound for Marine Paints: Laboratory Bioassays and Field Trials

Abstract

The extensive use of copper and booster biocides in antifouling (AF) paints has raised environmental concerns and the need to develop new AF agents. In the present study, 18 alkaloids derived from terrestrial plants were initially evaluated for AF activity using laboratory bioassays with the bryozoan Bugula neritina and the barnacle Balanus albicostatus. The results showed that 4 of the 18 alkaloids were effective in inhibiting larval settlement of B. neritina, with an EC range of 6.18 to 43.11 μM, and 15 of the 18 alkaloids inhibited larval settlement of B. albicostatus, with EC values ranging from 1.18 to 67.58 μM. Field trials that incorporated five alkaloids respectively into paints with 20% w/w indicated an in situ AF efficiency of evodiamine, strychnine, camptothecin (CPT), and cepharanthine, with the most potent compound being CPT, which also exhibited stronger AF efficiency than the commercial antifoulants cuprous oxide and zinc pyrithione in the field over a period of 12 months. Further field trials with different CPT concentrations (0.1 to 20% w/w) in the paints suggested a concentration-dependent AF performance in the natural environment, and the effective concentrations to significantly inhibit settlement of biofoulers in the field were ≥ 0.5% w/w (the efficiency of 0.5% w/w lasted for 2 months). Moreover, CPT toxicity against the crustacean Artemia salina, the planktonic microalgae Phaeodactylum tricornutum and Isochrysis galbana, was examined. The results showed that 24 h LC of CPT against A. salina was 20.75 μM, and 96 h EC (growth inhibition) values of CPT to P. tricornutum and I. galbana were 55.81 and 6.29 μM, respectively, indicating that CPT was comparatively less toxic than several commercial antifoulants previously reported. Our results suggest the novel potential application of CPT as an antifoulant.

Pinturas antiincrustantes derivadas de plantas terrestres una solución segura para el ambiente en el control de la bioincrustación

“…La mayoría de los resultados satisfactorios se observaron en ocho especies de la familia Fabaceae, pertenecientes a ocho géneros diferentes (Stupak, et al, 2003;Zhou, et al, 2009;Qian, et al, 2010;Feng, et al, 2018;Agostini, et al, 2019;Clasen y Kesel, 2019). La familia Fabaceae, también llamada Leguminosae, es una de las familias botánicas más grandes e importantes (Di Stasi e Hiruma-Lima, 2002), y está compuesta por aproximadamente 19.000 especies distribuidas en 695 géneros (Giulietti, et al, 2005).…”

“…Entre los resultados obtenidos en los artículos, se identifican bacterias (microfouling) e invertebrados (macrofouling) como organismos objetivos para la inhibición. El 24% de los resultados antiincrustantes satisfactorios se centraron en el microfouling (Xu, et al, 2005;Qian, et al, 2010;Salta, et al, 2013;Pérez, et al, 2014;Nandhini y Revathi, 2016;Moodie, et al, 2018;Agostini, et al, 2019;Nadir, et al, 2020), el 61% en el macrofouling (Takasawa, et al, 1990;Etoh, et al, 2002;Stupak, et al, 2003;Goransson, et al, 2004;Angarano, et al, 2007;Pérez, et al, 2007;Feng, et al, 2009;Zhou, et al, 2009;Qian, et al, 2010;Bellotti, et al, 2014;Cui, et al, 2014;Huang, et al, 2014;Pérez, et al, 2014;Bogdan, et al, 2018;Feng, et al, 2018;Clasen y Kesel, 2019), y el 14% en ambas comunidades. En el Anexo 2 se presenta la lista de organismos inhibidos por la acción de extractos, compuestos o moléculas derivadas de plantas terrestres.…”

Research Strategies to Develop Environmentally Friendly Marine Antifouling Coatings

“…As the barnacle grows, its edges will destroy the anticorrosion layer on the hull surface, thereby accelerating the hull corrosion [ 4 ]. As shown in Figure 1 [ 5 ], when the hull surface is attached, fouling organisms will corrode the hull surface and increase the roughness of the hull surface, thereby reducing the speed of the ship [ 6 , 7 , 8 ], increasing fuel consumption and greenhouse gas emissions [ 9 , 10 ]. In recent years, with the rapid development of offshore industries such as submarine oil and marine power generation, the damage of marine fouling organisms to man-made facilities has become more severe.…”

“From the Nature for the Nature”: An Eco-Friendly Antifouling Coating Consisting of Poly(lactic acid)-Based Polyurethane and Natural Antifoulant

“…For instance, coatings containing camptothecin derived from terrestrial plants have been found to be effective in laboratory bioassays and field trails. 42 However, the complex structure and high cost of camptothecin make it challenging for commercial marine antifouling coating application. Coatings consisting of tannins and nonreactive polymers such as vinyl resin or chlorinated rubber have also been reported.…”

“…Natural product antifoulants (NPAs) extracted from natural sources are an ideal choice for antifouling coatings because they exhibit excellent eco-friendliness. Until now, butenolide, terpenoids, camptothecin, and phenolic compounds from marine bacteria, algae, and terrestrial plants have been reported to effectively inhibit the attachment of diverse fouling organisms. − Moreover, NPA-based antifouling coatings have also been explored in the past few years. For instance, coatings containing camptothecin derived from terrestrial plants have been found to be effective in laboratory bioassays and field trails .…”