ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC%28Nc1c%28cccc1C%29C%29C2N%28C%29CCCC2/file?format=sdf&get3d=True  -- O%3DC%28Nc1c%28cccc1C%29C%29C2N%28C%29CCCC2 could not be loaded.