Synonyms: Formosanan-16-carboxylicacid, 19-methyl-2-oxo-, (19a)-; Mitraphyllic acid (6CI);Spiro[3H-indole-3,6'(4'aH)-[1H]pyrano[3,4-f]indolizine]-4'-carboxylic acid,1,2,5',5'a,7',8',10',10'a-octahydro-1'-methyl-2-oxo-, [1'S-(1'a,4'aa,5'aa,6'b,10'ab)]-