Anti-barnacle activity of novel simple alkyl isocyanides derived from citronellol

Twenty novel simple alkyl isocyanides derived from citronellol were synthesized and evaluated for their antifouling activity and toxicity against cypris larvae of the barnacle, Balanus amphitrite. The anti-barnacle activity of the synthesized isocyanides was in the EC50 range of 0.08-1.49 g ml-1. Simple isocyanides containing a benzoate and chloro group showed the most potent anti-barnacle activity. In addition, none of the synthesized compounds showed significant toxicity and LC50 values were 10 g ml-1. The LC50/EC50 ratios of almost all of the synthesized compounds were 102. The results indicate that these simple isocyanides are promising low-toxicity antifouling agents.