CC(=O)c1c(O)cc(O)c(C(C)=O)c1O    mol33900    0_1
CC(=O)c1c(O)cc(O)c(C(C)=O)c1[O-]    mol33900    -1_1
[CH2-]C(=O)c1c(O)cc(O)c(C(C)=O)c1O    mol33900    -1_2
CC(=O)c1c([O-])cc(O)c(C(C)=O)c1O    mol33900    -1_3