2,5,6-TRIBROMO-1-METHYLGRAMINE, AN ANTIFOULING SUBSTANCE FROM THE MARINE BRYOZOAN ZOOBROTRYON-PELLUCIDUM

In our screening for antifouling substances using laboratory-reared larvae of the barnacle Balanus amphitrite, the crude extract of the marine bryozoan Zoobotryon pellucidum exhibited promising activity. Bioassay-guided isolation led to the isolation of 2,5,6-tribromo-1-methylgramine as an effective inhibitor. Its inhibitory activity was 6 times as strong as that of bis-(n-butyltin)oxide (TBTO), while its toxicity to cyprid larvae was one-tenth that of TBTO. This substance also inhibited settlement of the blue mussel Mytilus edulis.