Avermectin chemistry and action: ester- and ether-type candidate photoaffinity probes Original Research Article

Avermectin B1a () is a potent anthelmintic, insecticide, miticide and chloride channel activator on interaction with a specific nerve membrane site analyzed by binding assays with [3H]. Candidate photoaffinity probes were prepared replacing the dioleandrosyl substituent with potential isosteric esters and ethers approximating the original overall atom length and terminating in a phenyl moiety substituted with azido, iodo or hydroxy. Several of the candidates met the goal of high potency on mouse, housefly and fruit fly brain chloride channels with IC50 values of 7–57 nM in competing for the [3H] binding site.