LAUSR

A series of unsaturated fatty acids in fish oil and their corresponding ethanolamide metabolites were explored to find active fish oil components of anti-allergic activity in vitro. Ethanolamides of omega-3 fatty acids (α-linolenic acid, EPA, and DHA) were found to possess promising anti-allergic activity, whereas free fatty acids and ethanolamides of other fatty acids exhibited no or weak potency. Based on this finding, structure-activity relationships of DHA-ethanolamide (DHEA) derivatives were investigated to yield better fatty acid derivatives with enhanced anti-allergic activity in vitro and in vivo. When the ethanolamide moiety of DHEA was replaced by substituted sulfonamide functionality, highly promising potency was provided in vitro. Compound 59 showed improved anti-allergic activity in vivo over DHEA. The results indicate that optimized DHEA derivatives have enhanced anti-allergic activity in vitro and in vivo, and the resulting structures will be an important basis for further development of bioavailable derivatives with promising allergy suppressive activity.