InChI=1S/C20H15N3O4S/c24-20-17(7-22-15-3-1-13-9-28(25,26)10-14(13)5-15)16-6-12(2-4-18(16)23-20)19-8-21-11-27-19/h1-8,11,22H,9-10H2,(H,23,24)/b17-7-