Verruculogen

Verruculogen is a mycotoxin produced by certain strains of "aspergillus" that belongs to a class of naturally occurring 2,5-diketopiperazines. It is an annulated analogue of cyclo(L-Trp-L-Pro) which belongs to the most abundant and structurally diverse class of tryptophan-proline 2,5-diketopiperazine natural products. It produces tremors in mice due to its neurotoxic properties. It also tested positive in a "Salmonella"/mammalian microsome assay and was shown to be genotoxic. It is a potent blocker of calcium-activated potassium channels.
Synthesis.
Both verruculogen and its isoprenyl derivative fumitremorgin A belong to the only family of alkaloids with an eight-membered endoperoxide ring, and both have been synthesised involving ligand-controlled C–H borylation.