ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C20H23N/c1-4-19-20(15-16(2)21(19)3,17-11-7-5-8-12-17)18-13-9-6-10-14-18/h4-14,16H,15H2,1-3H3/b19-4 /file?format=sdf&get3d=True  -- InChI=1S/C20H23N/c1-4-19-20(15-16(2)21(19)3,17-11-7-5-8-12-17)18-13-9-6-10-14-18/h4-14,16H,15H2,1-3H3/b19-4  could not be loaded.