InChI=1S/C19H22O2/c20-18(13-10-17-11-14-19(21)15-12-17)9-5-4-8-16-6-2-1-3-7-16/h1-4,6-8,11-12,14-15,18,20-21H,5,9-10,13H2/b8-4+