ERROR opening https://cactus.nci.nih.gov/chemical/structure/n2snc%28/C1%3DC/CCN%28C%29C1%29c2SCCCCCC/file?format=sdf&get3d=True  -- n2snc%28/C1%3DC/CCN%28C%29C1%29c2SCCCCCC could not be loaded.