Rifaximin EP Impurity E

Chemical Name: 5,17,19,21-Tetrahydroxy-23-methoxy-2,4,12,16,18,20,22-heptamethyl-2,7-(epoxypentadeca[1,11,13]trienimino)naphtho[2,1-b]furan-1,6,9,11(2H)-tetrone 21-Acetate; 1,4-Dideoxy-1,4-dihydro-1,4-dioxo-rifamycin