Antifouling Marine Coatings with a Potentially Safer and Sustainable Synthetic Polyphenolic Derivative

Abstract

The development of harmless substances to replace biocide-based coatings used to prevent or manage marine biofouling and its unwanted consequences is urgent. The formation of biofilms on submerged marine surfaces is one of the first steps in the marine biofouling process, which facilitates the further settlement of macrofoulers. Anti-biofilm properties of a synthetic polyphenolic compound, with previously described anti-settlement activity against macrofoulers, were explored in this work. In solution this new compound was able to prevent biofilm formation and reduce a pre-formed biofilm produced by the marine bacterium, Pseudoalteromonas tunicata. Then, this compound was applied to a marine coating and the formation of P. tunicata biofilms was assessed under hydrodynamic conditions to mimic the marine environment. For this purpose, polyurethane (PU)-based coating formulations containing 1 and 2 wt.% of the compound were prepared based on a prior developed methodology. The most effective formulation in reducing the biofilm cell number, biovolume, and thickness was the PU-based coating containing an aziridine-based crosslinker and 2 wt.% of the compound. To assess the marine ecotoxicity impact of this compound, its potential to disrupt endocrine processes was evaluated through the modulation of two nuclear receptors (NRs), peroxisome proliferator-activated receptor γ (PPARγ), and pregnane X receptor (PXR). Transcriptional activation of the selected NRs upon exposure to the polyphenolic compound (10 µM) was not observed, thus highlighting the eco-friendliness towards the addressed NRs of this new dual-acting anti-macro- and anti-microfouling agent towards the addressed NRs.

Derivatives of Trimethoxybenzoic Acid and Gallic Acid as Potential Efflux Pump Inhibitors: In Silico and In Vitro Studies

“…Compound 12 (Figure 1) was previously reported in a US patent [9]. (1), gallic acid (2) and their derivatives (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13).…”

“…Compounds 3-13 were tested against Escherichia coli American Type Culture Collection (ATCC) 25922, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Enterococcus faecalis ATCC 29212, Salmonella enterica serovar Typhimurium SL1344, and the oxacillin-and methicillin-resistant S. aureus 272123. Among the tested compounds (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13), none was active against the ATCC strains tested. However, compound 10 displayed antibacterial activity against the S. aureus 272123 and S. Typhimurium strains, of 100 and 50 µM, respectively.…”

“…Our group has recently described the synthesis of "optimized" gallic acid derivatives as antifouling agents [7,8]. Fouling is a phenomenon caused by macro-and microorganisms, such as bacteria and fungi.…”

“…Fouling is a phenomenon caused by macro-and microorganisms, such as bacteria and fungi. As part of a screening of compounds with potential antimicrobial/EPI activity, a series of 11 synthetic derivatives of trimethoxybenzoic acid (1) and gallic acid (2) was studied (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13), Figure 1) regarding potential antimicrobial activity and EP inhibition [7][8][9].…”

Design and In Situ Validation of Low-Cost and Easy to Apply Anti-Biofouling Techniques for Oceanographic Continuous Monitoring with Optical Instruments

“…Finally, nano-coatings of the glass surface, coatings of the sensing area of the sensors or bio-mimetics shapes and materials are emerging techniques that have shown their potential mostly in laboratory experiments [ 33 , 34 , 35 , 36 , 37 ].…”