InChI=1S/C27H42O4/c1-3-5-7-9-10-11-12-13-15-17-23-31-27(29)25-20-18-24(19-21-25)26(28)30-22-16-14-8-6-4-2/h15,17-21H,3-14,16,22-23H2,1-2H3/b17-15+