Five benzamide deriatives containing capsaicin were synthesized which have similar structures to capsaicin. Their yield was high. The monomers synthesized were characterized by IR, 1H NMR and MS spectroscopy. Cha-racterization data are in agreement with the proposed structures of the products. These five compounds exhibit bacterial inhibition and N-[4-hydroxy-2-methyl-5-（methylthio）benzyl]benzamide（HMMBBA）, for instance, shows that the minimal inhibitory concentrations（MIC） of HMMBBA are 0.125 and 0.25 mg/mL on Staphyloccocus aureus and Escherichia coli, respectively. A static test site was set up in the eighth harbor to investigate the antifouling effectiveness of the five new antifoulants. Five-month exposure experiments were performed on sets of panels coated with each of antifouling coatings, and the results were compared to that of the test panel without antifouling coating. Test boards with antifouling coating were covered with just a macroscopic fouling organism such as Balanus. The results of the present paper demonstrate that new antifoulants represent an alternative to the biocidal antifouling paint.
