Showing structure for [1-carboxy-2-(1-{3-carboxy-9,10-dioxo-4,12-diazatetracyclo[6.5.2.0⁴,¹⁵.0¹¹,¹⁴]pentadeca-1(13),8(15),11(14)-trien-7-yl}imidazol-4-yl)ethyl]trimethylazanium