資料來源 : pyDict
黃色色素
資料來源 : Webster's Revised Unabridged Dictionary (1913)
Xanthin \Xan"thin\, n. [Gr. xanqo`s yellow.]
1. (Physiol. Chem.) A crystalline nitrogenous body closely
related to both uric acid and hypoxanthin, present in
muscle tissue, and occasionally found in the urine and in
some urinary calculi. It is also present in guano. So
called from the yellow color of certain of its salts
(nitrates).
2. (Chem.) A yellow insoluble coloring matter extracted from
yellow flowers; specifically, the coloring matter of
madder. [Formerly written also {xanthein}.]
3. (Chem.) One of the gaseous or volatile decomposition
products of the xanthates, and probably identical with
carbon disulphide. [Obs.]
Xanthine \Xan"thine\, n. Also Xanthin \Xan"thin\ . [Gr. xanqo`s
yellow.] (Physiol. Chem.)
A white microcrystalline nitrogenous compound, {C5H4O2N4},
present in muscle tissue, in the liver, spleen, pancreas, and
other organs, and also in urine (in small quantities) and
some urinary calculi, and in the juices of certain plants; --
so called because it leaves a yellow residue when evaporated
to dryness with nitric acid. Xanthine is closely related to
uric acid.