InChI=1S/C18H18O7/c1-10(19)25-18(2,3)15(20)9-23-17-11-4-5-16(21)24-14(11)8-13-12(17)6-7-22-13/h4-8,15,20H,9H2,1-3H3/t15-/m1/s1