Spiramycin EP Impurity B

Chemical Name: (4R,5S,6S,7R,9R,10R,11E,13E,16R)-6-[[3,6-dideoxy-4-O-(2,6-dideoxy-3-C-methyl-α-l-ribo-hexopyranosyl)-3-(dimethylamino)-β-d-glucopyranosyl]oxy]-4-hydroxy-7-(2-hydroxyethyl)-5-methoxy-9,16-dimethyl-10-[[2,3,4,6-tetradeoxy-4-(dimethylamino)-β-d-erythro-hexopyranosyl]oxy]oxacyclohexadeca-11,13-dien-2-one (spiramycin IV)