The molecule is an ammonium ion derivative obtained from protonation of the nitrogens of emetine. It is the major species at pH 7.3. It is a conjugate acid of an emetine.
(2S,3R,11bS)-2-[[(1R)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolin-2-ium-1-yl]methyl]-3-ethyl-9,10-dimethoxy-1,2,3,4,5,6,7,11b-octahydrobenzo[a]quinolizin-5-ium