Studies on the synthesis,pungency and anti-biofouling performance of capsaicin analogues

Ten capsaicin analogues were synthesized and their pungency degrees were determined through Scoville Organoleptic Test.The relationship between the structure and pungency degree of these capsaicin analogues was discussed.Then four of these capsaicin analogues with higher pungency degree were picked out and added to anti-biofouling paints as repellents to study their anti-biofouling performance by shallow sea buoyant raft hung-plate experimentation.The results showed that capsaicin and dihydrocapsaicin exhibited equally good anti-biofouling performance while nordihydrocapsaicin and N-vanillylnonanamide had poor anti-biofouling performance.Experimental results also showed that the paints with only 0.1% capsaicin or dihydrocapsaicin as repellent without any other biocides had also exhibited good anti-biofouling performance,which provided a new idea for developing novel,more environment-friendly and Cu2O-free antifouling paints.