2CHM:
reference: A novel series of potent and selective PDE5 inhibitors with potential for high and dose-independent oral bioavailability., Allerton CM, Barber CG, Beaumont KC, Brown DG, Cole SM, Ellis D, Lane CA, Maw GN, Mount NM, Rawson DJ, Robinson CM, Street SD, Summerhill NW, J Med Chem. 2006 Jun 15;49(12):3581-94. PMID: 16759100

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).