O=C([O-])COO    mol31341    -1_1
O=C(O)CO[O-]    mol31341    -1_2
O=C(O)[CH-]OO    mol31341    -1_3
O=C([O-])[CH-]OO    mol31341    -2_1
O=C(O)[CH-]O[O-]    mol31341    -2_2
O=C([O-])CO[O-]    mol31341    -2_3