Butenedioic

Part of speech: adjective

Definitions

1. Relating to or derived from butenedioic acid, a four-carbon dicarboxylic acid with a double bond between its central carbons
2. Describing a chemical compound that contains or is derived from butenedioic acid, a dicarboxylic acid existing as maleic and fumaric forms
3. Of or pertaining to butenedioic acid, the unsaturated four-carbon diacid whose cis and trans isomers are maleic and fumaric acid

Etymology: Butenedioic is a systematic chemical name, built from its parts. "Butane" gives the four-carbon chain, and that stem comes from "butyric acid," named for Latin "butyrum," butter, because the acid was first found in rancid butter. "-ene" marks a double bond between two carbons, and "-dioic" marks two carboxylic acid groups. The compound has two better-known common names, and neither comes from the systematic one. Maleic acid takes its name from malic acid, which comes from Latin "malum," apple, because malic acid was first isolated from apples. Fumaric acid is named after the fumitory plant, "Fumaria," in which it occurs. The two isomers have the same atoms but differ in how they are arranged around the double bond. Maleic acid folds into a cis shape, while fumaric acid stretches out in a trans shape. That difference in geometry gives them very different melting points.