InChI=1S/C18H20O4/c1-9-5-6-13-10(2)8-22-16-12(4)17(20)18(21,7-11(3)19)15(9)14(13)16/h5-6,10,21H,7-8H2,1-4H3/t10-,18-/m1/s1