InChI=1S/C17H20O9S/c1-27-7-9(15(21)22)6-8-4-2-3-5-10(8)25-17-13(20)11(18)12(19)14(26-17)16(23)24/h2-6,11-14,17-20H,7H2,1H3,(H,21,22)(H,23,24)/b9-6-