Pyridine is a basic heterocyclic organic compound with the chemical formula C5H5N. It is structurally related to benzene, with one methine group (=CH-) replaced by a nitrogen atom. Pyridine is not abundant in nature, except for the leaves and roots of belladonna (Atropa belladonna) and in marshmallow (Althaea officinalis, Guimauve officinale). Pyridine derivatives, however, are often part of biomolecules such as alkaloids. Building block for many inhibitors of enzymes