Synonyms: 4,8-Secosenecionan-8,11,16-trione,15,20-epoxy-15,20-dihydro-12-hydroxy-4-methyl-, (15b,20R)-; Fukinotoxin; Fukinotoxin (neutral); NSC279000; NSC 288753; Petasitenine; Petasitenine (neutral);Spiro[2,9-dioxa-14-azabicyclo[9.5.1]heptadec-11-ene-4,2'-oxirane]-3,8,17-trione,7-hydroxy-3',6,7,14-tetramethyl-, [1R-[1R*,4R*(R*),6R*,7R*]]-