Showing structure for (1s,11s,18r,20r,21r,22s)-9-oxo-12-oxa-8,17-diazaheptacyclo[15.5.2.0¹,¹⁸.0²,⁷.0⁸,²².0¹¹,²¹.0¹⁵,²⁰]tetracosa-2,4,6,14-tetraen-17-ium-17-olate