The molecule is the intermediate in the biosynthesis of vitamin B12 from uroporphyrinogen III in which six methyl groups have been introduced into the tetrapyrrole framework, together with ring contraction and reduction. It is a conjugate acid of a precorrin-6Y(6-).
3-[(1R,2S,3S,4Z,7S,11S,15Z,17R,18R,19R)-8,13,17-tris(2-carboxyethyl)-2,7,12,18-tetrakis(carboxymethyl)-1,2,7,11,17-pentamethyl-3,10,18,19,21,24-hexahydrocorrin-3-yl]propanoic acid