ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC1N%28c2c%28N%28C%28%3DO%29C1%29C%29n%28nc2C%29C%29c3ccccc3/file?format=sdf&get3d=True  -- O%3DC1N%28c2c%28N%28C%28%3DO%29C1%29C%29n%28nc2C%29C%29c3ccccc3 could not be loaded.