Isolation and Structure Elucidation of Lolilline, a Possible Biosynthetic Precursor of the Lolitrem Family of Tremorgenic Mycotoxins

Lolilline ( 1 ), a new indole−diterpenoid, was isolated from extracts of the seed of Lolium perenne infected with the endophytic fungus Acremonium lolii . Lolilline contained structural features present in both the lolitrem mycotoxins and the simpler indole−diterpenoid tremorgen paxilline, suggesting that lolilline may be an intermediate in the biosynthesis of the lolitrems from the presumed precursor paxilline. Although paxilline, terpendole C, and lolitrem B were found to be tremorgenic, lolilline was not, providing new insight into structure−activity relationships within the indole−diterpenoids. Keywords: Acremonium lolii; Lolium perenne; endophyte; lolitrem; paxilline; terpendole; tremor; ryegrass staggers; neurotoxin; mycotoxin; biosynthesis