Antifouling Agents Against the Benthic Marine Diatom, Navicula Salinicola Homarine from the Gorgonians Leptogorgia Virgulata and L. Setacea and Analogs

Résumé du livre

At concentrations found in the gorgonian corals, Leptogorgia virgulata (L.) and L. setacea (L.), homarine (N-methyl-2-carboxypyridine) and water-soluble extracts from the gorgonians that contained homarine inhibited the growth of the potential fouling diatom, Navicula salinicola Hust., by 50-60%. Homarine comprised 0.3 and 0.25% of the fresh weight of L. virgulata and L. setacea, respectively, and the water-soluble extracts comprised 4.0 and 3.0% of the fresh weight of the gorgonians, respectively. Three compounds structurally related to homarine including, in order of most to least active, nicotinic acid, picolinic acid, and pyridine, also reduced growth of N. salinicola. The activity of these compounds in the diatom assay suggests that the carboxyl group at the 2 position of the pyridine ring is important for activity and that N-methylation is not important. We conclude that chemical defense against fouling is operative in Leptogorgia species. Evidence from the literature for combined chemical and mechanical defenses by Leptogorgia and other organisms against fouling is presented.