ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C18H18N4O4/c1-3-26-18(23)17(13(2)19-14-9-5-4-6-10-14)21-20-15-11-7-8-12-16(15)22(24)25/h4-12,20H,3H2,1-2H3/b19-13+,21-17?/file?format=sdf&get3d=True -- InChI=1S/C18H18N4O4/c1-3-26-18(23)17(13(2)19-14-9-5-4-6-10-14)21-20-15-11-7-8-12-16(15)22(24)25/h4-12,20H,3H2,1-2H3/b19-13+,21-17? could not be loaded.