InChI=1S/C21H32O7/c1-10(8-13-6-4-11(2)14-7-5-12(3)15(13)14)9-27-21-18(24)16(22)17(23)19(28-21)20(25)26/h8,11,13-14,16-19,21-24H,4-7,9H2,1-3H3,(H,25,26)/b10-8+