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 10 mg/L. Among the candidates, compound 23 showed the best anthelmintic activity than other compounds against D. intermedius infestation with EC 50 value of 0.85 mg/L. The structure–activity relationship analysis confirmed that the anthelmintic activities of derivatives were determined by the length of ‘ linker ’ (R 1 substitute position) and the substitute group in R 2 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 . [ABSTRACT FROM AUTHOR]