9-acetyl-6,9,11-trihydroxy-8,10-dihydro-7H-tetracene-5,12-dione

2-(9-ethylcarbazole-3-carbonyl)benzoic acid

9-ethyl-3,6-bis-(2-carboxy-benzoyl)-carbazole

3-butylimino-2-benzofuran-1-one

2-(2-醌)-1H-茚-1,3(2H)-二酮