Main Page | See live article | Alphabetical index In organic chemistry, a pyrrole is a five membered aromatic ring, 4 elements of which are carbon atoms, one element of which is a nitrogen atom. The molecular formula for a pyrrole is C4NH5. The structure is: Pyrroles are components of larger aromatic rings, including the porphyrins of heme, the chlorins and bacteriochlorins of chlorophyll, and the corrin ring of vitamin B12. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.