InChI=1S/C19H24O4/c1-12(2)4-6-14-10-18-16(17(11-20)19(14)22)9-8-15(23-18)7-5-13(3)21/h4-5,7,10-11,13,15,21-22H,6,8-9H2,1-3H3/b7-5+