ERROR opening https://cactus.nci.nih.gov/chemical/structure/c13OCOc3cccc1CNCCc%28c%28OC%29cc2I%29cc2OC/file?format=sdf&get3d=True -- c13OCOc3cccc1CNCCc%28c%28OC%29cc2I%29cc2OC could not be loaded.