InChI=1S/C15H13N3O4S2/c1-8(13-14(19)18-15(16)23-13)11-6-7-12(22-11)9-2-4-10(5-3-9)24(17,20)21/h2-7H,1H3,(H2,16,18,19)(H2,17,20,21)/b13-8-