Pyrroline

Part of speech: noun

Definitions

1. Any of a family of partly unsaturated five-membered ring compounds containing one nitrogen atom, used as building blocks in organic chemistry
2. A class of nitrogen-containing heterocyclic organic compounds whose five-membered ring contains a single double bond and one nitrogen atom
3. A chemical compound built on a five-atom ring with one nitrogen and one carbon-carbon double bond, found in various natural and synthetic substances

Etymology: Pyrroline is a chemical name built like a family tree: its roots reach back to a Greek word for fire. Ancient Greek "pûr" meant fire, and "pŭrrhós" meant fiery or flame-coloured, a word that gave rise to the name of the element-like building block chemists later called pyrrole. The "pyrrole" part is the key link. In German, the compound was given the name Pyrrol, and English adopted it as pyrrole, a five-membered ring compound with a nitrogen atom, named for the reddish colour it produces when a pine splint dipped in hydrochloric acid is used to test for it. Pyrroline is simply pyrrole with the ring partly saturated, and the English suffix "-ine" marks it as a chemical name. The suffix here is a chemist's convention rather than a word with its own story, so the name works by adding a familiar ending to an existing chemical name.