Diaqua(5-carboxybenzene-1,3-dicarboxylato-κ<i>O</i><sup>1</sup>)[8-ethyl-5-oxo-2-(piperazin-4-ium-1-yl)-5,8-dihydropyrido[2,3-<i>d</i>]pyrimidine-6-carboxylato-κ<sup>2</sup><i>O</i><sup>5</sup>,<i>O</i><sup>6</sup>]zinc monohydrate
Acta crystallographica. Section E