InChI=1S/C19H18O8/c20-12-4-1-11(2-5-12)3-6-15(21)27-10-19(25)8-7-13-14(17(22)23)9-26-18(24)16(13)19/h1-9,13,16,18,20,24-25H,10H2,(H,22,23)/b6-3+