InChI=1S/C20H28O7S/c1-6-12(4)20(22)27-18-10-15(11(2)3)19-14(7-8-26-28(23,24)25)17(21)9-16(19)13(18)5/h6-7,11,15-16,18-19H,5,8-10H2,1-4H3,(H,23,24,25)/b12-6-,14-7+