InChI=1S/C18H22O8/c1-2-3-6-10-9-5-4-7-11(13(9)17(23)24-10)25-18-16(22)15(21)14(20)12(8-19)26-18/h4-7,12,14-16,18-22H,2-3,8H2,1H3/b10-6+