InChI=1S/C19H20O15/c20-7-5-6(2-4-9(21)33-15(18(30)31)13(25)16(26)27)1-3-8(7)32-19-12(24)10(22)11(23)14(34-19)17(28)29/h1-5,10-15,19-20,22-25H,(H,26,27)(H,28,29)(H,30,31)/b4-2+