InChI=1S/C15H20O7/c1-7-3-4-15(20)13(7)5-8(22-10(17)9(13)16)12(2,19)14(15)6-21-11(14)18/h7-9,16,19-20H,3-6H2,1-2H3/t7-,8?,9+,12+,13+,14+,15-/m1/s1