InChI=1S/C15H16O4/c1-14(2)6-5-10(16)15-9(14)4-3-8-7-18-12(11(8)15)19-13(15)17/h3,5-6,9,11-12H,4,7H2,1-2H3/t9-,11+,12+,15-/m0/s1