InChI=1S/C21H28O4/c1-14(8-7-11-21(5,24)13-20(22)23)9-10-18-15(2)12-19(25-6)17(4)16(18)3/h7-12,24H,13H2,1-6H3,(H,22,23)/b10-9+,11-7+,14-8+