InChI=1S/C18H22O4/c1-9-5-6-12-11(7-9)15-13(22-18(12,3)4)8-10(2)14(16(15)19)17(20)21/h7-8,11-12,19H,5-6H2,1-4H3,(H,20,21)/t11-,12+/m1/s1