InChI=1S/C16H16O5/c1-15-4-3-11(17)16(2)9-6-12(18)20-7-8(9)5-10(13(15)16)21-14(15)19/h3-6,10-11,13,17H,7H2,1-2H3/t10-,11-,13+,15+,16+/m1/s1