The molecule is a zwitterion obtained by transfer of a proton from the 5-hydroxy group to the tertiary amino group of rifampicin. It is a tautomer of a rifampicin.
(7S,9E,11S,12R,13S,14R,15R,16R,17S,18S,19E,21Z)-13-acetyloxy-15,17,27,29-tetrahydroxy-11-methoxy-3,7,12,14,16,18,22-heptamethyl-26-[(E)-(4-methylpiperazin-4-ium-1-yl)iminomethyl]-6,23-dioxo-8,30-dioxa-24-azatetracyclo[23.3.1.14,7.05,28]triaconta-1(29),2,4,9,19,21,25,27-octaen-2-olate