InChI=1S/C16H16O4/c1-3-4-5-6-7-14-8-10-16(20-14)11-9-15(12-18-16)19-13(2)17/h7-8,10,15H,9,11-12H2,1-2H3/b14-7-/t15-,16+/m1/s1