The molecule is a precorrin carboxylic acid anion arising from global deprotonation of the seven carboxy groups and protonation of the secondary amino group of the precorrin derivative hydrogenobyrinic acid; major species at pH 7.3. It is a conjugate base of a hydrogenobyrinic acid and a hydrogenobyrinate(4-).
3-[(1R,2S,3S,4Z,7S,8S,9Z,13S,14Z,17R,18R,19R)-3,13,17-tris(2-carboxylatoethyl)-2,7,18-tris(carboxylatomethyl)-1,2,5,7,12,12,15,17-octamethyl-3,8,13,18,19,21-hexahydrocorrin-21-ium-8-yl]propanoate