Azithromycin EP Impurity K Catalogue A535211 CAS 612534-95-9 M.W 762.99 M.F C38H70N2O13 Specifications FAQs (2S,4aR,4'R,5'S,6'S,7R,8S,9R,10R,13R,15R,16R,17S,17aS)-16-(((2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyltetrahydro-2H-pyran-2-yl)oxy)-7-ethyl-5',8,9,15-tetrahydroxy-4'-methoxy-4',6',8,10,11,13,15,17-octamethylhexadecahydro-4H-spiro[[1,3]dioxino[4,5-m][1,6]oxaazacyclopentadecine-2,2'-pyran]-5(4aH)-one
