InChI=1S/C21H28O6/c1-13-7-6-10-18-17(26-21(2,3)27-18)9-5-4-8-14-11-15(22)12-16(23)19(14)20(24)25-13/h4,8,11-13,17-18,22-23H,5-7,9-10H2,1-3H3/b8-4-/t13-,17-,18-/m0/s1