InChI=1S/C21H29NO7S/c23-21(22-13-7-8-14-22)19(29-30(24,25)26)10-6-4-2-1-3-5-9-17-11-12-18-20(15-17)28-16-27-18/h5,9,11-12,15,19H,1-4,6-8,10,13-14,16H2,(H,24,25,26)/b9-5+