InChI=1S/C18H20O13/c1-26-12-6(4-8-13(15(12)27-2)29-5-28-8)3-7(19)17(25)31-18-11(22)9(20)10(21)14(30-18)16(23)24/h3-4,9-11,14,18-22H,5H2,1-2H3,(H,23,24)/b7-3-