InChI=1S/C21H28O4/c1-14(7-6-8-18(13-22)12-21(23)24)9-10-19-15(2)11-20(25-5)17(4)16(19)3/h6-11,18,22H,12-13H2,1-5H3,(H,23,24)/b8-6+,10-9+,14-7+