noun. A five-membered heterocyclic ring compound, C₄H₅N, having an odor similar to chloroform, that is the parent compound of protoporphyrin.

noun. Any of a class of aromatic heterocyclic compounds containing a ring of four carbon atoms and a nitrogen atom; especially the simplest one, C4H5N.

"First reported in 1993 (ref. 2), it is part of a family of compounds known as pyrrole-imidazole alkaloids, which may help to deter fish from snacking on the sponge or prevent microbes from taking up residence."

beer-can  bellybutton  benzenoid  chelate  cook-fire  

azole