Synthesis and Anti-barnacle Activities of Novel Isocyanocyclohexane Compounds Containing an Ester or an Ether Functional Group

Abstract

Ten novel isocyanocyclohexane compounds that possess an oxygenic functional group at the 4-position were synthesized and evaluated for their antifouling activity against the larvae of the barnacle Balanus amphitrite with the aim of exploring the structure – activity relationships further. The anti-barnacle effect of the synthesized compounds was in the EC₅₀ range of 0.0096 – 17.0 μg ml⁻¹. Some ester derivatives exhibited extremely high antifouling activities, and none of the synthesized isocyanocyclohexane compounds showed significant toxicity. The results suggest that the ester function is one of the important groups in the expression of potent antifouling activity in isocyano compounds.

Keywords:

• antifouling
• barnacle
• isocyanide
• iscyanocyclohexane
• structure – activity relationships

Acknowledgements

We express our sincere thanks to Professor N Fusetani of The University of Tokyo for his helpful suggestions. We also gratefully acknowledge Associate Professor K Okamoto of The University of Tokyo for providing a collection of barnacles. This work was partially supported by a Grant-in-Aid for the Encouragement of Young Scientists (B), 14760120, from the Ministry of Education, Science, Sports, and Culture, and a Sasakawa Scientific Research Grant from The Japan Science Society.