ERROR opening https://cactus.nci.nih.gov/chemical/structure/N%5BC%40%40H%5D%28CC%28O%29%3DO%29C%28O%29%3DO/file?format=sdf&get3d=True  -- N%5BC%40%40H%5D%28CC%28O%29%3DO%29C%28O%29%3DO could not be loaded.