| Structure | Name/CAS No. | Articles | 
|---|---|---|
                        ![]()  | 
                    2-(4-Hydroxyphenylazo)benzoic acid
                     CAS:1634-82-8  | 
                    
                    |
                        ![]()  | 
                    3-Indoleacrylic acid
                     CAS:29953-71-7  | 
                    
                    |
                        ![]()  | 
                    3-Indoleacrylic acid
                     CAS:1204-06-4  |