Antifouling barnacles

According to Schneider and Allerman (2001), Alcalase is the name of an enzyme that might be used to hydrolyse e.g. barnacle proteins. Less than 5 wt% (solvent-free basis) enzyme is used in an antifouling paint (Schneider and Allerman, 2001) and so a seawater-soluble carrier material should probably be... 

ANTIFOULING AGENTS. Various chemical substances added to paints and coatings to combat mildew and crustaceous formations, such as barnacles on the hull of a ship. In the past, large quantities of mercury compounds have been used in this manner. With growing environmental concern over possible mercury pollution, manufacturers have been turning to other, sometimes less efficacious compounds, Research continues to find compounds of a less toxic, but equally effective power of the mercury compounds. Bis(tributyltin) fluoride has been used on ship bottoms. See also Mercury. 

The antifouling sponge metabolite pseudoceratidine (1245) was characterized from the Japanese Pseudoceratina purpurea (1253). This spermidine derivative has excellent larval settlement and metamorphosis inhibitory activity against the barnacle Balanus amphitrite (ED50 = 8.0 pig cm-3), and is the first example of an antifouling spermidine derivative. The four tauroacidins A (1246/1247) and B (1248/1249), with tyrosine kinase inhibitory activity, were isolated from the... 

Hirota H, Tomono Y, Fusetani N (1996) Terpenoids with Antifouling Activity Against Barnacle Larvae from the Marine Sponge Acanthella cavernosa. Tetrahedron 52 2359... 

Hirota, H., Tomono, Y., and Fusetani, N., Terpenoids with antifouling activity against barnacle larvae from the marine sponge Acanthella cavernosa, Tetrahedron, 52, 2359, 1996. 

The result is that barnacles are often the first macrofoulers to colonize a protected surface.100 Once growth of barnacles on toxic metal coatings is initiated, the surface rapidly fails because barnacles act as nontoxic platforms for other organisms. As a result of these kinds of field evidence, the U.S. Navy supported basic barnacle research for almost four decades, and barnacles were the only macrofoulers included in initial studies of natural product antifoulants supported by the U.S. Navy. Most of this work was conducted by the Costlow group at the Duke University Marine Laboratory.47... 

Yamamoto, H., Satuito, C.G., Yamazaki, M., Natoyama, K., Tachibana, A., and Fusetani, N., Neurotransmitter blockers for antifoulants against planktonic larvae of the barnacle Balaam amphitrite and the mussel Mytilus galloprovincialis, Bioufouling, 13, 69, 1998. 

These molecules were shown to be potent inhibitors of chitinase, an enzyme involved in the ecdysis of many insects and crustaceans, whose inhibitors are supposed to control the settlement of barnacles and, therefore, could have a potential application as antifouling agents. Unfortunately, no data are available in the literature about cytotoxic, immunosuppressive, or antibacterial activities of styloguanidines and, thus, a comparison with the potently bioactive congeners palau amines is not possible. 

The triorganotin species have been used as industrial biocides for over 30 years [117, 118]. Examples are triphenyltin hydroxide (structure 5) for fungal diseases on celery, rice, sugar beets, and coffee tricyclohexylstannyl-1,2,4-triazole (structure 6) as an acaricide for apple, pear, and citrus fruit trees bistributyltin oxide (structure 7) as a wood preservative and tributyltin-methylacrylate monomers (structure 8) polymerized with other acrylates to yield a marine antifoulant polymer that prevents the build of up barnacles, algae, and other marine animals on ships. 

Antifouling agentskiU. or prevent the attachment of organisms (such as barnacles) that bind to boat bottoms and other underwater surfaces. 

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