Antifungal principle of Penicillium luteo-aurantium was isolated and identified as radicicol (1). A new metabolite of the molecular formula C22H28N6O4, designated meleagrin, was isolated from Penicillium meleagrinum. It was clarified that meleagrin has a structural similarity with tremorgenic mycotoxins, such as fumitremorgin A and B (synonymous to lanosulin), verruculogen, and roquefortin C and D.