InChI=1S/C21H22O7/c1-4-5-14-7-12-8-17(24)21(3,19(25)15(12)10-27-14)28-20(26)18-11(2)6-13(22)9-16(18)23/h4-9,15,19,22-23,25H,10H2,1-3H3/b5-4+/t15-,19+,21-/m0/s1