1 DI0 Dirithromycin 1.000 2 ERN (3r,4s,5s,6r,7r,9r,10s,11s,12r,13s,14r)-10-amino-6-{[(2s,3r,4s,6r)-4-(dimethylamino)-3-hydroxy-6-methyltetrahydro-2h-py ran-2-yl]oxy}-14-ethyl-7,12,13-trihydroxy-4-{[(2r,4r,5s,6s)-5-hydroxy-4-methoxy-4,6-dimethyltetrahydro-2h-pyran-2-yl]oxy }-3,5,7,9,11,13-hexamethyloxacyclotetradecan-2-one 0.703 3 ERY Erythromycin a 0.703