InChI=1S/C18H19NO8S/c1-26-17-10-12(2-8-15(17)20)3-9-18(22)19-11-16(21)13-4-6-14(7-5-13)27-28(23,24)25/h2-10,16,20-21H,11H2,1H3,(H,19,22)(H,23,24,25)