(1R-(1 alpha,2 beta,4 beta))-2-ethyl-1,2,3,4,6,11- hexahydro-2,5,7,10-tetrahydroxy-6,11-dioxo-4- ((2,3,6-trideoxy-3-(dimethylamino)-alpha-L-lyxo- hexopyranosyl)oxy)-1-naphthacenecarboxylic acid, methyl ester