Isolation and Structure Elucidation of Lolitrem A, a Tremorgenic Mycotoxin from Perennial Ryegrass Infected with Acremonium lolii

Abstract

Lolitrem A, the second most abundant minor lolitrem in endophyte-infected perennial ryegrass, has been isolated and its structure determined by mass spectrometry and one- and two-dimensional NMR spectroscopy. Lolitrem A, which other workers have suggested to be 7α-hydroxylolitrem B, was found to be an inseparable mixture of the 44R and 44S isomers of 44,45-epoxylolitrem C. An assignment of the methyl group proton and carbon resonances of lolitrem B is also reported. The intensity and time course of the tremorgenic activity of lolitrem A in mice were identical to that of lolitrem B.