InChI=1S/C20H20O10/c1-27-12-8-11(28-14(21)9-12)7-6-10-4-2-3-5-13(10)29-20-17(24)15(22)16(23)18(30-20)19(25)26/h2-9,15-18,20,22-24H,1H3,(H,25,26)/b7-6+