ERROR opening https://cactus.nci.nih.gov/chemical/structure/C%28CO%29C%3D1%5BC%40%5D2%28C%28C%29%28C%29%5BC%40%5D%28C2%29%28CC1%29/file?format=sdf&get3d=True -- C%28CO%29C%3D1%5BC%40%5D2%28C%28C%29%28C%29%5BC%40%5D%28C2%29%28CC1%29 could not be loaded.