English: Structural formula of ziconotide. The file was made with ChemBioDraw Ultra 14. The structural formula of ziconotide can be seen in a review by Marc Diederich: https://dx.doi.org/10.3390/md13084967 (open access). The bottom-left part of the figure in the review contains a mistake: starting from the disulfide bond to the bottom, it is –S–S–CH₂–CH(NH₂)–CO–NH–CH(C₄H₈NH₂)–CO–NH–CH₂–. The peptide sequence can be seen in an article by Joseph McGivern: https://dx.doi.org/10.2147/nedt.2007.3.1.69 or https://www.dovepress.com/ziconotide-a-review-of-its-pharmacology-and-use-in-the-treatment-of-pa-peer-reviewed-article-NDT (open access). The stereochemistry is based on Protein Data Bank: http://www.rcsb.org/pdb/explore/explore.do?structureId=1DW5.