(3E)-3-[amino(hydroxy)methylidene]-5a-chloro-1-(dimethylamino)-4a,5,7,12-tetrahydroxy-11-methyl-5,5a,11,11a,12,12a-hexahydro-5,11-epoxytetracene-2,4,6(1H,3H,4aH)-trione