InChI=1S/C21H28O4/c1-20-8-7-17-15(16(20)4-5-18(20)19(25)11-22)3-2-13-10-14(24)6-9-21(13,17)12-23/h10,12,15-18,22H,2-9,11H2,1H3/t15?,16?,17?,18-,20+,21-/m1/s1