10-((1-Carboxyethylidene)amino)-9-hydroxy-2,5,11-trimethyl-6H-pyrido(4,3-b)carbazolium acetate (salt) 6H-Pyrido(4,3-b)carbazolium, 10-((1-carboxyethylidene)amino)-9-hydroxy-2,5,11-trimethyl-, acetate (salt) 89683-32-9