Synthesis and anthelmintic activity of coumarin-imidazole hybrid derivatives against Dactylogyrus intermedius in goldfish.

With an intention to find more potent anti-parasite agents, four bromoalkane substituted coumarin derivatives (1-4) and twenty coumarin-imidazole hybrid derivatives were synthesized and screened for their anthelmintic activity and the acute toxicity. Anti-parasites results confirmed that most coumarin derivatives retained their anthelmintic activity against Dactylogyrus intermedius at the dose range from 1 to 10mg/L. Among the candidates, compound 23 showed the best anthelmintic activity than other compounds against D. intermedius infestation with EC50 value of 0.85mg/L. The structure-activity relationship analysis confirmed that the anthelmintic activities of derivatives were determined by the length of 'linker' (R1substitute position) and the substitute group in R2 position. The active data confirmed that six carbon atoms length of 'linker' and benzimidazole substitute group can increased the anthelmintic activity of compound, significantly. On the basis of these results, compound 23 can be used as a potential lead compound for the development of commercial drug against D. intermedius.