earticle

영어

Thiazolidinedione (TD) derivatives exhibit algicidal activity against harmful algae such as H. akashiwo, C. marina and C. polykrikoides, as reported previously. In this study, the efficacies and selectivities of newly synthesized TD derivatives were tested by analyzing the structure–ctivity relationships of various TD derivatives. To investigate structure-activity relationships for growth inhibition of harmful algae, we added a methylene group between the cyclohexyl ring and oxygen of 5-(3-chloro-4-hydroxybenzylidene)-TD, which decreased the inhibitory potency of compound 17. Interestingly, another addition of a methylene group significantly increased the inhibitory potency against C. polykrikoides, as seen for compound 20. The addition of 1 μM compound 17 resulted in the rupture of harmful algae after less than 10 hours. Compound 17 was applied to both harmful and non-harmful algae and showed a drastic reduction in the efficiency of photosystem II, resulting in reduced photosynthetic oxygen evolution. Compound 17 at a 5 μM concentration destroyed all of the harmful algae, while algicidal activity against non-harmful algae did not exceed 30% of the control within the concentration range tested. In contrast, an herbicide, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), tested at a 5 μM concentration, exhibited 40-70% algicidal activity relative to that of the control against both harmful and non-harmful algae. Compound 17 is a promising lead compound for the development of algicides addressing the universal need for effective harmful algal management.