Antifouling assays

Cvejic JH, Rohmer M (2000) C02 as main carbon source for isoprenoid biosynthesis via the mevalonate-independent methylerythritol 4-phosphate route in the marine diatoms Phaeodactylum tricomutum and Nitzschia ovalis. Phytochemistry 53 21-28 de Nys R, Steinberg PD, Willemsen P, Dworjanyn SA, Gabelish CL, King RJ (1995) Broad-spectrum effects of secondary metabolites from the red alga Delisea pulchra in antifouling assays. Biofouling 8 259-271... 

Henrikson, A.A. and Pawlik, J.R., A new antifouling assay method results from field experiments using extracts of four marine organisms, J. Exp. Mar. Biol. Ecol., 194, 157, 1995. 

Tributyltin compounds used as antifouling agents on boats have had serious toxic effects upon many mollusks, including populations of oysters and dog whelks. Females of the latter species developed a condition known as imposex, which rendered them infertile and caused local extinction of the population in shallow coastal waters. Imposex provides the basis for a valuable biomarker assay. 

Controlled release epoxy formulations in which tin is chemically anchored as tributyltin carboxylate to the polymer chain are discussed. NMR evidence is presented to establish that rapid exchange exists in tributyltin carboxylates. Consequently, even the interfacial reaction between tributyltin carboxylates and chloride is very fast equilibrium constants are reported for the reaction between tributyltin acrylate in hexane and sodium chloride in water. IR spectra, gas chromatographic retention time, chloride assay, and the complex intensity pattern of the molecular ion peaks in the mass spectrum show that the product of the reaction is tributyltin chloride, suggesting that it is the chemical species responsible for antifouling activity in marine environment. 

One of the most successful biomarker assays is the measurement of imposex in dog whelks (Nu-cella lapillus, which have brightly-colored shells). This phenomenon is caused by tributyl tins (TBTs), widely used as antifouling coatings in boats (see Section 12.3.2). TBTs impose male characteristics on females, leading to a reduction in reproductive performance and local extinction of dog whelk populations in the most contaminated sites. 

The Scandinavian samples possess muscle relaxant activity in the electrically stimulated isolated guinea pig ileum assay (47) and antiviral activity against Herpes and influenza virus (48). Furthermore, the Scandinavian collections contain a mixture of simple monoterpenes with antifouling activity (49). Unfortunately, the muscle relaxing effect, the antifouling activity, and the antiviral activity of the Canadian population have not been reported. 

Chem. Descrip. Bis (tributyltin) oxide CAS 56-35-9 EINECS/ELINCS 200-268-0 Uses Antimicrobial for paper mill slime control, industrial cooling water, sec. oil recovery, hospital use, textiles, plastics, urethane foam, paper preservation antifoulant for ship-bottom paints wood presenrative Properties Straw-colored clear Iiq. sol. in org. soivs. relatively insol. in water m.w. 596 sp.gr. 1.17 dens. 9.7 Ib/gal f.p. < -45 C b.p. 180 C (2 mm) flash pt. (TCC) > 100 C 96% assay, 38.8% tin Toxicology Extremely irritating to eyes and skin can cause eye damage prolonged/repeated skin contact can cause chemical bums Biotrend 500 [ISP]... 

For the primary antifouling screening, a barnacle assay is used in most cases. For this test, mass reared cyprid larvae of barnacle species like for example Balanus amphitrite are injected in dishes containing solutions of test compounds in seawater. After one hour, the settlement inhibition in regard to biodde-free controls is determined. 

---