InChI=1S/C21H26O4/c1-13(8-7-11-21(5)19(25-21)20(22)23)9-10-17-14(2)12-18(24-6)16(4)15(17)3/h7-12,19H,1-6H3,(H,22,23)/b10-9+,11-7+,13-8+