4G1F:
reference: Structure-based design of pyridopyrimidinediones as dipeptidyl peptidase IV inhibitors., Lam B, Zhang Z, Stafford JA, Skene RJ, Shi L, Gwaltney SL 2nd, Bioorg Med Chem Lett. 2012 Nov 1;22(21):6628-31. doi: 10.1016/j.bmcl.2012.08.110., Epub 2012 Sep 7. PMID: 23025999

This OCA Structure page
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