InChI=1S/C20H21NO6S/c1-26-14-4-3-5-19(20(22)23)21-28(24,25)18-12-8-16(9-13-18)15-6-10-17(27-2)11-7-15/h6-13,19,21H,5,14H2,1-2H3,(H,22,23)/t19-/m1/s1