InChI=1S/C20H23NO4/c1-21-8-7-12-10-15(24-3)20(25-4)18-16(12)13(21)9-11-5-6-14(23-2)19(22)17(11)18/h5-6,10,13,22H,7-9H2,1-4H3/t13-/m0/s1