InChI=1S/C16H16N2O4S/c1-23-9-6-14(21)15-17-13(16(22)18(15)7-8-19)10-11-2-4-12(20)5-3-11/h2-5,8,10,20H,6-7,9H2,1H3/p-1/b13-10+