InChI=1S/C20H28O4/c1-13(7-8-18(22)23)6-5-10-20(4)11-9-16-12-17(21)14(2)15(3)19(16)24-20/h6,12,21H,5,7-11H2,1-4H3,(H,22,23)/b13-6+/t20-/m1/s1