Marine Natural Products with Antifouling Activity

A special issue of Marine Drugs (ISSN 1660-3397).

Deadline for manuscript submissions: closed (15 May 2021) | Viewed by 44812

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Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
Interests: marine natural compounds; antifouling; toxicity; coatings; environment
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CIIMAR|Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, s/n, 4450-208 Matosinhos, Portugal
Interests: marine biology and ecology; marine environmental health; marine biotechnology; sustainable antifouling strategies; natural bioactive metabolites; bioproducts and biomaterials
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Marine fouling affects most man-made surfaces temporarily or permanently immersed in the sea, causing important economic costs. Intense research is aimed at methods for preventing or reducing fouling development. The most widespread solution to inhibit fouling is to make surfaces unsuitable for settlers by coating them with antifouling paints containing toxic compounds. Most such antifouling agents give undesirable effects on nontarget species, including commercially important ones. The search for new nontoxic antifouling technologies has become a necessity, particularly after the ban of organotin compounds such as tributyltin (TBT), once the most widespread and used antifouling agent. Alternative organic and metal-based biocides are now used in antifouling paints, but their possible toxic effects on the aquatic environment are not yet fully understood. A nontoxic alternative for antifouling protection comes from the possibility of adopting natural antifouling compounds that are and may be found in marine sessile invertebrates like sponges, bryozoans, corals, and tunicates. Such metabolites prevent their producers from being fouled on by other organisms. As natural marine compounds, they may inhibit settlement through a nontoxic mechanism without adverse effects to the environment. Such compounds could be developed into active ingredients of new antifouling coatings. So far, a rather limited number of natural product antifoulants (NPAs) has been isolated from marine organisms, but a huge reservoir of compounds with potential antifouling activity is hidden in marine organisms. The Special Issue on marine natural products with antifouling activity aims at the discovery of such compounds their activity, toxicit,y and potential application in environmentally friendly antifouling coatings.

Prof. Tom Turk
Dr. Joana Reis Almeida
Guest Editors

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Keywords

  • marine natural compounds
  • antifouling
  • toxicity
  • coatings
  • environment

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Published Papers (13 papers)

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Research

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8 pages, 273 KiB  
Article
Quantification of a Sulfated Marine-Inspired Antifouling Compound in Several Aqueous Matrices: Biodegradation Studies and Leaching Assays from Polydimethylsiloxane Coatings
by Cátia Vilas-Boas, Virgínia Gonçalves, Paolo De Marco, Emília Sousa, Madalena Pinto, Elisabete R. Silva, Maria Elizabeth Tiritan and Marta Correia-da-Silva
Mar. Drugs 2022, 20(9), 548; https://doi.org/10.3390/md20090548 - 25 Aug 2022
Cited by 1 | Viewed by 1859
Abstract
The development of marine-inspired compounds as non-toxic antifouling (AF) agents has been pursued in the last years. Sulfur is the third most common element in seawater. Sulfur is present in oxygenated seawater as sulfate anion (SO42−), which is the most [...] Read more.
The development of marine-inspired compounds as non-toxic antifouling (AF) agents has been pursued in the last years. Sulfur is the third most common element in seawater. Sulfur is present in oxygenated seawater as sulfate anion (SO42−), which is the most stable combination of sulfur in seawater, and several promising AF secondary metabolites with sulfate groups have been described. However, sulfated compounds proved to be an analytical challenge to quantify by HPLC. Taking these facts into consideration, this work presents the development and validation of a method for the quantification of gallic acid persulfate (GAP) in seawater and ultrapure water matrix, based on hydrophilic interaction liquid chromatography (HILIC). This method was used to evaluate GAP stability following several abiotic and biotic degradation assays, and to quantify its release in seawater from room-temperature-vulcanizing polydimethylsiloxane commercial coating. GAP was very stable in several water matrices, even at different pH values and in the presence/absence of marine microorganisms and presented a leaching value lower than 0.5%. This work discloses HILIC as an analytical method to overcome the difficulties in quantifying sulfated compounds in water matrices and highlights the potential of GAP as a promising long-lasting coating. Full article
(This article belongs to the Special Issue Marine Natural Products with Antifouling Activity, 2nd Edition)
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12 pages, 2155 KiB  
Article
Antifouling Marine Coatings with a Potentially Safer and Sustainable Synthetic Polyphenolic Derivative
by Ana R. Neves, Luciana C. Gomes, Sara I. Faria, João Sousa, Raquel Ruivo, Inês Páscoa, Madalena Pinto, Emília Sousa, Miguel M. Santos, Elisabete R. Silva, Marta Correia-da-Silva and Filipe Mergulhão
Mar. Drugs 2022, 20(8), 507; https://doi.org/10.3390/md20080507 - 5 Aug 2022
Cited by 8 | Viewed by 3053
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 [...] Read more.
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. Full article
(This article belongs to the Special Issue Marine Natural Products with Antifouling Activity, 2nd Edition)
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14 pages, 2778 KiB  
Article
Effective Synthesis and Antifouling Activity of Dolastatin 16 Derivatives
by Loida O. Casalme, Keisuke Katayama, Yoshiki Hayakawa, Kensuke Nakamura, Arisa Yamauchi, Yasuyuki Nogata, Erina Yoshimura, Fuyuhiko Matsuda and Taiki Umezawa
Mar. Drugs 2022, 20(2), 124; https://doi.org/10.3390/md20020124 - 4 Feb 2022
Cited by 6 | Viewed by 2585
Abstract
Some derivatives of dolastatin 16, a depsipeptide natural product first obtained from the sea hare Dolabella auricularia, were synthesized through second-generation synthesis of two unusual amino acids, dolaphenvaline and dolamethylleuine. The second-generation synthesis enabled derivatizations such as functionalization of the aromatic ring [...] Read more.
Some derivatives of dolastatin 16, a depsipeptide natural product first obtained from the sea hare Dolabella auricularia, were synthesized through second-generation synthesis of two unusual amino acids, dolaphenvaline and dolamethylleuine. The second-generation synthesis enabled derivatizations such as functionalization of the aromatic ring in dolaphenvaline. The derivatives of fragments and whole structures were evaluated for antifouling activity against the cypris larvae of Amphibalanus amphitrite. Small fragments inhibited the settlement of the cypris larvae at potent to moderate concentrations (EC50 = 0.60-4.62 μg/mL), although dolastatin 16 with a substituent on the aromatic ring (24) was much less potent than dolastatin 16. Full article
(This article belongs to the Special Issue Marine Natural Products with Antifouling Activity, 2nd Edition)
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16 pages, 1320 KiB  
Article
Antifouling Activity of Halogenated Compounds Derived from the Red Alga Sphaerococcus coronopifolius: Potential for the Development of Environmentally Friendly Solutions
by Maxence Quémener, Stefanos Kikionis, Marilyne Fauchon, Yannick Toueix, Fanny Aulanier, Antonios M. Makris, Vassilios Roussis, Efstathia Ioannou and Claire Hellio
Mar. Drugs 2022, 20(1), 32; https://doi.org/10.3390/md20010032 - 28 Dec 2021
Cited by 12 | Viewed by 2790
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. [...] Read more.
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. Full article
(This article belongs to the Special Issue Marine Natural Products with Antifouling Activity, 2nd Edition)
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12 pages, 3153 KiB  
Article
Synthetic Analogue of Butenolide as an Antifouling Agent
by Ho Yin Chiang, Jinping Cheng, Xuan Liu, Chunfeng Ma and Pei-Yuan Qian
Mar. Drugs 2021, 19(9), 481; https://doi.org/10.3390/md19090481 - 25 Aug 2021
Cited by 15 | Viewed by 3382
Abstract
Butenolide derivatives have the potential to be effective and environmentally friendly antifouling agents. In the present study, a butenolide derivative was structurally modified into Boc-butenolide to increase its melting point and remove its foul smell. The structurally modified Boc-butenolide demonstrated similar antifouling capabilities [...] Read more.
Butenolide derivatives have the potential to be effective and environmentally friendly antifouling agents. In the present study, a butenolide derivative was structurally modified into Boc-butenolide to increase its melting point and remove its foul smell. The structurally modified Boc-butenolide demonstrated similar antifouling capabilities to butenolide in larval settlement bioassays but with significantly lower toxicity at high concentrations. Release-rate measurements demonstrated that the antifouling compound Boc-butenolide could be released from polycaprolactone-polyurethane (PCL-PU)-based coatings to inhibit the attachment of foulers. The coating matrix was easily degraded in the marine environment. The performance of the Boc-butenolide antifouling coatings was further examined through a marine field test. The coverage of biofouler on the Boc-butenolide coatings was low after 2 months, indicating the antifouling potential of Boc-butenolide. Full article
(This article belongs to the Special Issue Marine Natural Products with Antifouling Activity)
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19 pages, 5904 KiB  
Article
The Effect of Molecular Weight on the Antimicrobial Activity of Chitosan from Loligo opalescens for Food Packaging Applications
by Luciana C. Gomes, Sara I. Faria, Jesus Valcarcel, José A. Vázquez, Miguel A. Cerqueira, Lorenzo Pastrana, Ana I. Bourbon and Filipe J. Mergulhão
Mar. Drugs 2021, 19(7), 384; https://doi.org/10.3390/md19070384 - 2 Jul 2021
Cited by 16 | Viewed by 4127
Abstract
The growing requirement for sustainable processes has boosted the development of biodegradable plastic-based materials incorporating bioactive compounds obtained from waste, adding value to these products. Chitosan (Ch) is a biopolymer that can be obtained by deacetylation of chitin (found abundantly in waste from [...] Read more.
The growing requirement for sustainable processes has boosted the development of biodegradable plastic-based materials incorporating bioactive compounds obtained from waste, adding value to these products. Chitosan (Ch) is a biopolymer that can be obtained by deacetylation of chitin (found abundantly in waste from the fishery industry) and has valuable properties such as biocompatibility, biodegradability, antimicrobial activity, and easy film-forming ability. This study aimed to produce and characterize poly(lactic acid) (PLA) surfaces coated with β-chitosan and β-chitooligosaccharides from a Loligo opalescens pen with different molecular weights for application in the food industry. The PLA films with native and depolymerized Ch were functionalized through plasma oxygen treatment followed by dip-coating, and their physicochemical properties were assessed by Fourier-transform infrared spectroscopy, X-ray diffraction, water contact angle, and scanning electron microscopy. Their antimicrobial properties were assessed against Escherichia coli and Pseudomonas putida, where Ch-based surfaces reduced the number of biofilm viable, viable but nonculturable, and culturable cells by up to 73%, 74%, and 87%, respectively, compared to PLA. Biofilm growth inhibition was confirmed by confocal laser scanning microscopy. Results suggest that Ch films of higher molecular weight had higher antibiofilm activity under the food storage conditions mimicked in this work, contributing simultaneously to the reuse of marine waste. Full article
(This article belongs to the Special Issue Marine Natural Products with Antifouling Activity)
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12 pages, 12138 KiB  
Article
Discovery of Antibiofilm Activity of Elasnin against Marine Biofilms and Its Application in the Marine Antifouling Coatings
by Lexin Long, Ruojun Wang, Ho Yin Chiang, Wei Ding, Yong-Xin Li, Feng Chen and Pei-Yuan Qian
Mar. Drugs 2021, 19(1), 19; https://doi.org/10.3390/md19010019 - 5 Jan 2021
Cited by 16 | Viewed by 4491
Abstract
Biofilms are surface-attached multicellular communities that play critical roles in inducing biofouling and biocorrosion in the marine environment. Given the serious economic losses and problems caused by biofouling and biocorrosion, effective biofilm control strategies are highly sought after. In a screening program of [...] Read more.
Biofilms are surface-attached multicellular communities that play critical roles in inducing biofouling and biocorrosion in the marine environment. Given the serious economic losses and problems caused by biofouling and biocorrosion, effective biofilm control strategies are highly sought after. In a screening program of antibiofilm compounds against marine biofilms, we discovered the potent biofilm inhibitory activity of elasnin. Elasnin effectively inhibited the biofilm formation of seven strains of bacteria isolated from marine biofilms. With high productivity, elasnin-based coatings were prepared in an easy and cost-effective way, which exhibited great performance in inhibiting the formation of multi-species biofilms and the attachment of large biofouling organisms in the marine environment. The 16S amplicon analysis and anti-larvae assay revealed that elasnin could prevent biofouling by the indirect impact of changed microbial composition of biofilms and direct inhibitory effect on larval settlement with low toxic effects. These findings indicated the potential application of elasnin in biofilm and biofouling control in the marine environment. Full article
(This article belongs to the Special Issue Marine Natural Products with Antifouling Activity)
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21 pages, 2559 KiB  
Article
Flavonoid Glycosides with a Triazole Moiety for Marine Antifouling Applications: Synthesis and Biological Activity Evaluation
by Daniela Pereira, Catarina Gonçalves, Beatriz T. Martins, Andreia Palmeira, Vitor Vasconcelos, Madalena Pinto, Joana R. Almeida, Marta Correia-da-Silva and Honorina Cidade
Mar. Drugs 2021, 19(1), 5; https://doi.org/10.3390/md19010005 - 24 Dec 2020
Cited by 22 | Viewed by 4567
Abstract
Over the last decades, antifouling coatings containing biocidal compounds as active ingredients were used to prevent biofouling, and eco-friendly alternatives are needed. Previous research from our group showed that polymethoxylated chalcones and glycosylated flavones obtained by synthesis displayed antifouling activity with low toxicity. [...] Read more.
Over the last decades, antifouling coatings containing biocidal compounds as active ingredients were used to prevent biofouling, and eco-friendly alternatives are needed. Previous research from our group showed that polymethoxylated chalcones and glycosylated flavones obtained by synthesis displayed antifouling activity with low toxicity. In this work, ten new polymethoxylated flavones and chalcones were synthesized for the first time, including eight with a triazole moiety. Eight known flavones and chalcones were also synthesized and tested in order to construct a quantitative structure-activity relationship (QSAR) model for these compounds. Three different antifouling profiles were found: three compounds (1b, 11a and 11b) exhibited anti-settlement activity against a macrofouling species (Mytilus galloprovincialis), two compounds (6a and 6b) exhibited inhibitory activity against the biofilm-forming marine bacteria Roseobacter litoralis and one compound (7b) exhibited activity against both mussel larvae and microalgae Navicula sp. Hydrogen bonding acceptor ability of the molecule was the most significant descriptor contributing positively to the mussel larvae anti-settlement activity and, in fact, the triazolyl glycosylated chalcone 7b was the most potent compound against this species. The most promising compounds were not toxic to Artemia salina, highlighting the importance of pursuing the development of new synthetic antifouling agents as an ecofriendly and sustainable alternative for the marine industry. Full article
(This article belongs to the Special Issue Marine Natural Products with Antifouling Activity)
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16 pages, 4411 KiB  
Article
Natural Cyanobacterial Polymer-Based Coating as a Preventive Strategy to Avoid Catheter-Associated Urinary Tract Infections
by Bruna Costa, Rita Mota, Paula Tamagnini, M. Cristina L. Martins and Fabíola Costa
Mar. Drugs 2020, 18(6), 279; https://doi.org/10.3390/md18060279 - 26 May 2020
Cited by 19 | Viewed by 3408
Abstract
Catheter-associated urinary tract infections (CAUTIs) represent about 40% of all healthcare-associated infections. Herein, the authors report the further development of an infection preventive anti-adhesive coating (CyanoCoating) meant for urinary catheters, and based on a natural polymer released by a marine cyanobacterium. CyanoCoating performance [...] Read more.
Catheter-associated urinary tract infections (CAUTIs) represent about 40% of all healthcare-associated infections. Herein, the authors report the further development of an infection preventive anti-adhesive coating (CyanoCoating) meant for urinary catheters, and based on a natural polymer released by a marine cyanobacterium. CyanoCoating performance was assessed against relevant CAUTI etiological agents, namely Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, methicillin resistant Staphylococcus aureus (MRSA), and Candida albicans in the presence of culture medium or artificial urine, and under biofilm promoting settings. CyanoCoating displayed a broad anti-adhesive efficiency against all the uropathogens tested (68–95%), even in the presence of artificial urine (58–100%) with exception of P. mirabilis in the latter condition. Under biofilm-promoting settings, CyanoCoating reduced biofilm formation by E. coli, P. mirabilis, and C. albicans (30–60%). In addition, CyanoCoating prevented large crystals encrustation, and its sterilization with ethylene oxide did not impact the coating stability. Therefore, CyanoCoating constitutes a step forward for the implementation of antibiotic-free alternative strategies to fight CAUTIs. Full article
(This article belongs to the Special Issue Marine Natural Products with Antifouling Activity)
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19 pages, 4634 KiB  
Article
Insights into the Synthesis, Secretion and Curing of Barnacle Cyprid Adhesive via Transcriptomic and Proteomic Analyses of the Cement Gland
by Guoyong Yan, Jin Sun, Zishuai Wang, Pei-Yuan Qian and Lisheng He
Mar. Drugs 2020, 18(4), 186; https://doi.org/10.3390/md18040186 - 31 Mar 2020
Cited by 13 | Viewed by 3830
Abstract
Barnacles represent one of the model organisms used for antifouling research, however, knowledge regarding the molecular mechanisms underlying barnacle cyprid cementation is relatively scarce. Here, RNA-seq was used to obtain the transcriptomes of the cement glands where adhesive is generated and the remaining [...] Read more.
Barnacles represent one of the model organisms used for antifouling research, however, knowledge regarding the molecular mechanisms underlying barnacle cyprid cementation is relatively scarce. Here, RNA-seq was used to obtain the transcriptomes of the cement glands where adhesive is generated and the remaining carcasses of Megabalanus volcano cyprids. Comparative transcriptomic analysis identified 9060 differentially expressed genes, with 4383 upregulated in the cement glands. Four cement proteins, named Mvcp113k, Mvcp130k, Mvcp52k and Mvlcp1-122k, were detected in the cement glands. The salivary secretion pathway was significantly enriched in the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of the differentially expressed genes, implying that the secretion of cyprid adhesive might be analogous to that of saliva. Lysyl oxidase had a higher expression level in the cement glands and was speculated to function in the curing of cyprid adhesive. Furthermore, the KEGG enrichment analysis of the 352 proteins identified in the cement gland proteome partially confirmed the comparative transcriptomic results. These results present insights into the molecular mechanisms underlying the synthesis, secretion and curing of barnacle cyprid adhesive and provide potential molecular targets for the development of environmentally friendly antifouling compounds. Full article
(This article belongs to the Special Issue Marine Natural Products with Antifouling Activity)
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Review

Jump to: Research

25 pages, 3251 KiB  
Review
Anti-Larval and Anti-Algal Natural Products from Marine Microorganisms as Sources of Anti-Biofilm Agents
by Kai-Ling Wang, Zheng-Rong Dou, Gao-Fen Gong, Hai-Feng Li, Bei Jiang and Ying Xu
Mar. Drugs 2022, 20(2), 90; https://doi.org/10.3390/md20020090 - 21 Jan 2022
Cited by 20 | Viewed by 5189
Abstract
Bacteria growing inside biofilms are more resistant to hostile environments, conventional antibiotics, and mechanical stresses than their planktonic counterparts. It is estimated that more than 80% of microbial infections in human patients are biofilm-based, and biofouling induced by the biofilms of some bacteria [...] Read more.
Bacteria growing inside biofilms are more resistant to hostile environments, conventional antibiotics, and mechanical stresses than their planktonic counterparts. It is estimated that more than 80% of microbial infections in human patients are biofilm-based, and biofouling induced by the biofilms of some bacteria causes serious ecological and economic problems throughout the world. Therefore, exploring highly effective anti-biofilm compounds has become an urgent demand for the medical and marine industries. Marine microorganisms, a well-documented and prolific source of natural products, provide an array of structurally distinct secondary metabolites with diverse biological activities. However, up to date, only a handful of anti-biofilm natural products derived from marine microorganisms have been reported. Meanwhile, it is worth noting that some promising antifouling (AF) compounds from marine microbes, particularly those that inhibit settlement of fouling invertebrate larvae and algal spores, can be considered as potential anti-biofilm agents owing to the well-known knowledge of the correlations between biofilm formation and the biofouling process of fouling organisms. In this review, a total of 112 anti-biofilm, anti-larval, and anti-algal natural products from marine microbes and 26 of their synthetic analogues are highlighted from 2000 to 2021. These compounds are introduced based on their microbial origins, and then categorized into the following different structural groups: fatty acids, butenolides, terpenoids, steroids, phenols, phenyl ethers, polyketides, alkaloids, flavonoids, amines, nucleosides, and peptides. The preliminary structure-activity relationships (SAR) of some important compounds are also briefly discussed. Finally, current challenges and future research perspectives are proposed based on opinions from many previous reviews. Full article
(This article belongs to the Special Issue Marine Natural Products with Antifouling Activity, 2nd Edition)
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21 pages, 1937 KiB  
Review
Marine Microbial-Derived Antibiotics and Biosurfactants as Potential New Agents against Catheter-Associated Urinary Tract Infections
by Shuai Zhang, Xinjin Liang, Geoffrey Michael Gadd and Qi Zhao
Mar. Drugs 2021, 19(5), 255; https://doi.org/10.3390/md19050255 - 29 Apr 2021
Cited by 18 | Viewed by 5889
Abstract
Catheter-associated urinary tract infections (CAUTIs) are among the leading nosocomial infections in the world and have led to the extensive study of various strategies to prevent infection. However, despite an abundance of anti-infection materials having been studied over the last forty-five years, only [...] Read more.
Catheter-associated urinary tract infections (CAUTIs) are among the leading nosocomial infections in the world and have led to the extensive study of various strategies to prevent infection. However, despite an abundance of anti-infection materials having been studied over the last forty-five years, only a few types have come into clinical use, providing an insignificant reduction in CAUTIs. In recent decades, marine resources have emerged as an unexplored area of opportunity offering huge potential in discovering novel bioactive materials to combat human diseases. Some of these materials, such as antimicrobial compounds and biosurfactants synthesized by marine microorganisms, exhibit potent antimicrobial, antiadhesive and antibiofilm activity against a broad spectrum of uropathogens (including multidrug-resistant pathogens) that could be potentially used in urinary catheters to eradicate CAUTIs. This paper summarizes information on the most relevant materials that have been obtained from marine-derived microorganisms over the last decade and discusses their potential as new agents against CAUTIs, providing a prospective proposal for researchers. Full article
(This article belongs to the Special Issue Marine Natural Products with Antifouling Activity)
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22 pages, 7384 KiB  
Review
Research Strategies to Develop Environmentally Friendly Marine Antifouling Coatings
by Yunqing Gu, Lingzhi Yu, Jiegang Mou, Denghao Wu, Maosen Xu, Peijian Zhou and Yun Ren
Mar. Drugs 2020, 18(7), 371; https://doi.org/10.3390/md18070371 - 18 Jul 2020
Cited by 157 | Viewed by 13395
Abstract
There are a large number of fouling organisms in the ocean, which easily attach to the surface of ships, oil platforms and breeding facilities, corrode the surface of equipment, accelerate the aging of equipment, affect the stability and safety of marine facilities and [...] Read more.
There are a large number of fouling organisms in the ocean, which easily attach to the surface of ships, oil platforms and breeding facilities, corrode the surface of equipment, accelerate the aging of equipment, affect the stability and safety of marine facilities and cause serious economic losses. Antifouling coating is an effective method to prevent marine biological fouling. Traditional organic tin and copper oxide coatings are toxic and will contaminate seawater and destroy marine ecology and have been banned or restricted. Environmentally friendly antifouling coatings have become a research hotspot. Among them, the use of natural biological products with antifouling activity as antifouling agents is an important research direction. In addition, some fouling release coatings without antifoulants, biomimetic coatings, photocatalytic coatings and other novel antifouling coatings have also developed rapidly. On the basis of revealing the mechanism of marine biofouling, this paper reviews the latest research strategies to develop environmentally friendly marine antifouling coatings. The composition, antifouling characteristics, antifouling mechanism and effects of various coatings were analyzed emphatically. Finally, the development prospects and future development directions of marine antifouling coatings are forecasted. Full article
(This article belongs to the Special Issue Marine Natural Products with Antifouling Activity)
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