Antifouling Compounds (eBook)

Contents 10
Defense of Benthic Invertebrates Against Surface Colonization by Larvae: A Chemical Arms Race 15
Introduction 15
1.1 15
Multiple Levels of Antifouling Defense 15
1.2 16
Overview of the Fouling Process 16
1.3 17
Biofouling as a Sequential Ecological Process 17
1.4 19
Ecological Importance of Antifouling Defense 19
Mechanisms 19
The Role of Biofilms and their Constituent Microbes in 20
The Role of Biofilms and their Constituent Microbes in Fouling 20
2.1 21
Interpreting the Effects of Biofilms on Larval Settlement 21
2.2 23
Specific Bacterial Strains within Biofilms as Positive Cues for 23
Settlement of Fouling Larvae 23
Modulation of Surface Bacteria by Invertebrates: Direct and Indirect Effects on Fouling 23
3.1 24
Antibiotic Chemistry: Maintaining a Bacteria-Free Surface as a 24
Defense against Fouling 24
3.2 25
Maintaining a Community of Host-Specific Bacteria to Block 25
Inductive Biofilm Formation 25
3.3 28
Attracting Strains that Chemically Deter Settlement of Fouling 28
Larvae 28
Eukaryotic Propagules 31
4.1 31
Sponges 31
Role of Basibont-Derived Chemistry in Defense against 31
4.2 35
Cnidarians 35
4.3 39
Ascidians 39
4.4 42
Bryozoans 42
Investigating Larval Behavior to Understand and Combat Fouling 42
5.1 43
Waterborne Signals and Chemically Mediated Navigation 43
5.2 44
Measuring Production and Release of Chemical Deterrents in 44
Situ 44
5.3 45
Behavior of Larvae around Chemically Defended Surfaces 45
5.4 47
Interpreting the Ecological Importance of Larval Toxicity in 47
Laboratory Assays 47
5.5 50
An Alternative Bioassay Design to Avoid Artifacts and 50
Concentration Effects 50
The Importance of Alternative Hypothesis Testing: Mechanical and Physical Defense 52
Conclusions 54
References 55
Furanones 68
Natural Furanones from Delisa 69
Natural Antifouling Activity of Furanones 71
2.1 71
Surface Delivery and Surface Quantification of Furanones 71
2.2 74
Bacterial Fouling 74
2.3 75
Macrofouling 75
The Mode of Action of Furanones – Inhibition of Bacterial Signalling Systems 76
The Development and Application of Furanones 79
4.1 80
Chemical Synthesis 80
4.2 84
Delivery 84
4.3 85
Inhibition of Pathogenic Phenotypes and the Development of 85
Anti-Infectives 85
4.4 88
Alternative Modes of Activity 88
4.5 90
Biomaterials and Biofilms 90
4.6 91
Alternative Quorum Sensing Inhibitor Applications 91
4.7 92
Macrofouling – Coatings and Polymers 92
4.8 94
Furanones, Biofouling and Biosignal Ltd. 94
References 94
Isocyano Compounds as Non-Toxic Antifoulants 100
Introduction 100
Natural Marine Isocyanides 101
Natural Antifouling Isocyanoterpenes 101
3.1 101
Sesquiterpenes 101
3.2 103
Diterpenes 103
The Structure-Activity Relationships of Synthetic Isocyano Compounds 103
4.1 104
Antifouling Activities of 3-Isocyanotheonellin and Analogues 104
4.2 107
Isocyanocyclohexanes 107
4.3 109
Isocyanobenzenes 109
4.5 110
4.4 110
Simple Linear Alkyl Isocyanides 110
A Large-Scale Synthesis of Isocyanide 44 110
Field Experiments with Isocyanide 44 112
Test Panel Preparation 112
5.2 113
Field Experiments 113
References 116
6 Conclusion 116
3-Alkylpyridinium Compounds as Potential Non-Toxic Antifouling Agents 118
Introduction 118
Origin, General Characteristics and Biological Activities of 119
3-Alkylpyridinium Compounds 119
Monomeric 3-Alkylpyridinium Compounds 121
Dimeric and Trimeric 3-Alkylpyridinium Compounds 122
Polymeric 3-Alkylpyridinium Compounds 122
5.1 123
Halitoxin and Amphitoxin 123
5.2 125
EGF-Active Factors 125
5.3 125
Polymeric Alkylpyridinium Salts (Poly-APS) 125
Ecological Significance of 3-Alkylpyridinium Compounds 132
Perspectives 133
References 134
5, 6-Dichloro-1-Methylgramine, a Non-Toxic Antifoulant Derived from a Marine Natural Product 138
Introduction 139
Antifouling Assay 139
2.1 139
Laboratory Culture of 139
2.2 140
Comparison of the Effect of TBTO on the Settlement Behavior 140
of Cyprids from Reared and Wild Adult Barnacles 140
Isolation of 2,5,6-Tribromo-1-Methylgramine from the Marine Bryozoan Zoobotryon pellucidum 142
Structure-Activity Relationships 143
Production of Antifouling Paints 145
Performance Evaluation Tests (Panel Tests) 146
Development of an Effective Antifouling Paint 147
7.1 147
Duration of Antifouling Performance 147
7.2 148
Control of DCMG-Release and Demonstration Tests 148
Public Acceptance (Risk Management) 149
8.1 149
Safety Test 149
8.2 150
Risk Evaluation 150
Summary and Future Perspectives 150
References 151
Biofilms 153
Introduction 153
Structure and Functional Properties of Marine Biofilms 155
2.1 155
Introduction 155
2.2 157
Phylogenetic Identification in Complex Microbial Communities 157
2.3 158
Algal Biofilms 158
Ulva Zoospores – a Model for Studying the Influence of Marine Microbial Biofilms on Biofouling Processes 159
3.1 160
Influence of Microbial Biofilms on Zoospore Settlement 160
3.2 161
Recognition of 161
acylhomoserine Lactones by Zoospores 161
3.3 164
Ecological and Applied Significance of Interspecific AHL 164
Signalling in Complex Marine Communities 164
Interactions of Biofilms and Bacterial Metabolites with Invertebrate Larvae 166
4.1 Mixed and Single Species Biofilms 166
4.2 169
Bacterial Products and Secondary Metabolites 169
4.3 170
Conclusions and Future Directions 171
References 173
Adrenoceptor and Other Pharmacoactive Compounds as Putative Antifoulants 182
Introduction 182
1.1 183
Some Basic Aspects of Pharmacoactive Compounds 183
G Protein-Coupled Receptors 184
Biogenic Amine Signaling and Implications in the Settlement of Barnacle Larvae 187
3.1 189
Serotonin (5-Hydroxytryptamine (5-HT)) 189
3.2 191
Histamine 191
3.3 192
Aminobutyric Acid (GABA) 192
3.4 192
Octopamine and Tyramine 192
3.5 194
The Catecholamines 194
Adrenoceptor Compounds 198
4.1 198
Settlement Inhibition of 198
Cypris Larvae 198
4.2 203
Surface Affinity and the Antifouling Approach 203
Conclusions 206
References 208
State-of-Art Methodology of Marine Natural Products Chemistry: Structure Determination with Extremely Small Sample Amounts 214
Introduction 214
Structural Determination from Terrestrial Sources 215
Structure Studies on Marine Natural Products 217
Structure Determination of an Ascidian Sperm-Attracting and -Activating Factor (SAAF) 220
Synthesis of Sperm-attracting and -activating Factor and its Epimer 224
Conclusion and Outlook 228
References 229
Subject Index 232