10'-Demethoxystreptonigrin 10'-Desmethoxystreptonigrin 136803-89-9 2-Pyridinecarboxylic acid, 5-amino-6-(7-amino-5,8-dihydro-6-methoxy-5,8-dioxo-2-quinolinyl)-4-(2-hydroxy-3-methoxyphenyl)-3-methyl-