Research progress of avermectin: A minireview based on the structural derivatization of avermectin

Avermectins, a fermentation-derived macrocyclic lactones isolated from Streptomyces avermitilis, exhibiting a long history as biopharmaceuticals used in agriculture, medical and veterinary fields. Due to the significant biological activity and low mammalian toxicity, avermectins have been recognized as one of the most market-competitive anthelmintics and insecticides, with research related to these compounds has been awarded the 2015 Nobel Prize in Physiology or Medicine. Avermectin molecules contain multiple reaction sites, such as carbon-carbon double bonds, hydroxyl groups and oleandrose, facilitating the further development of derivatives with improved physicochemical properties, bioavailability, pest spectrum, and efficacy by chemical modification. Presently, thousands of avermectin derivatives have been studied and various species have been commercialized for crop protection and pharmaceutical use. Herein, we review the research progress achieved on structural modification reactions of avermectin and further summarize their structure-activity relationships. This mini-review may provide important insights into the future development of efficient avermectin-based anthelmintics, fungicides, and insecticides.