InChI=1S/C18H14O5/c19-16-15(11-13-7-3-1-4-8-13)22-18(23-16,17(20)21)12-14-9-5-2-6-10-14/h1-11H,12H2,(H,20,21)/p-1/b15-11-/t18-/m0/s1