InChI=1S/C21H24O4/c1-13(2)4-8-17-19(24-3)10-5-14-6-11-20(25-21(14)17)16-9-7-15(22)12-18(16)23/h4-5,7,9-10,12,20,22-23H,6,8,11H2,1-3H3