pka_value	data_source	charge_state_pre	charge_state_post	microspecies_pre	microspecies_post	molid	smiles
4.5	IUPAC digitized pKa	0	-1	O=C(O)CCC(=O)NO	O=C([O-])CCC(=O)NO	mol9216	O=C(O)CCC(=O)NO
9.6	IUPAC digitized pKa	-1	-2	O=C([O-])CCC(=O)NO	O=C([O-])CCC(=O)N[O-]	mol9216	O=C(O)CCC(=O)NO