InChI=1S/C21H26O6/c1-7-14(3)20(22)26-11-9-10-16-12-18(25-6)19(13-17(16)24-5)27-21(23)15(4)8-2/h7-10,12-13H,11H2,1-6H3/b10-9+,14-7-,15-8-