InChI=1S/C19H20O4/c20-15-11-17(10-9-14-5-2-1-3-6-14)22-18(12-15)13-16-7-4-8-19(21)23-16/h1-6,8,11,16,18H,7,9-10,12-13H2/t16-,18+/m1/s1