Chemistry and Biology of Ustiloxin Analogs as Mycotoxins

Ustiloxin analogs, including ustiloxins and phomopsins, are a group of cyclopeptide mycotoxins produced by fungi. They are a 13-membered macrocyclic ring and an ether linkage between tyrosine and isoleucine as the core structure. They are ribosomally synthesized and post-translationally modified peptides. Up to now, about 21 ustiloxin analogs have been isolated from either pathogenic or medicinal fungi, mainly including Ustilaginoidea virens, Cordyceps militaris, Aspergillus flavus, and Phomopsis leptostromiformis. They are toxic to plants and animals and pose a serious threat to the health of humans and domestic animals. Detoxification of ustiloxin A has been accomplished through oxidative deamination, oxidative decarboxylation, and hydroxylation. Analytical methods for the detection of ustiloxin analogs have been developed, mainly based on chromatographic techniques and immunoassays. Significant progress has been achieved in the biosynthesis and synthesis of ustiloxin analogs. This review provides valuable insights into the management of ustiloxin analogs and their producing fungi, as well as the potential applications of this kind of mycotoxin.