InChI=1S/C18H16O7/c1-6-5-8(19)10-11-9(6)14-18(23,17(3,4)7(2)24-14)13(20)12(11)16(22)25-15(10)21/h5,7,19,23H,1-4H3/t7-,18+/m0/s1