Showing structure for (1r,4s,12r,13r,21s)-20-oxo-5,15-diazahexacyclo[11.5.2.1¹,¹².0⁴,¹².0⁶,¹¹.0¹⁵,²¹]henicosa-6,8,10-triene-4-carboxylic acid