xanthine

noun

xan·thine | \ ˈzan-ˌthēn

Definition of xanthine

: a feebly basic compound C₅H₄N₄O₂ that occurs especially in animal or plant tissue, is derived from guanine and hypoxanthine, and yields uric acid on oxidation also : any of various derivatives of xanthine (such as methylxanthine)

History and Etymology for xanthine

borrowed from German Xanthin, from Xanthoxyd, an earlier name for the substance (borrowed from English xanthic oxide; xanthic from Greek xanthós "yellow" + -ic entry 1) + -in -in entry 1 — more at xantho-

Note: The German name Xanthin was apparently introduced by the German chemist Leopold Gmelin (1788-1853) in Handbuch der Chemie, 4. Auflage, 5. Band (Heidelberg, 1852), p. 514. Gmelin thought the name Xanthin was preferable to Xanthoxyd, but hesitated to recommend it because Xanthin was already in use for a yellow pigment found in the madder plant ("welcher Name vorzuziehen wäre, wenn nicht auch das Krappgelb so hiesse"). (Note that the name Hypoxanthin had already been suggested for a substance from which xanthine is formed by oxidation—see hypoxanthine.) English xanthic oxide was introduced by Geneva-born British physician Alexander Marcet (1770-1822) in An Essay on the Chemical History and Medical Treatment of Calculous Disorders (London, 1817). Marcet explained the name of the substance, which he had obtained from a urinary calculus, as follows (p. 101): "The term Xanthic Oxyd, from ξανθος yellow, has occurred to me as an appropriate name, because it alludes to a striking, and probably characteristic property of the substance in question, (that of forming a lemon-coloured compound when acted upon by nitric acid,) and yet does not imply any systematic notion as to its composition."