Xanthosine is a
nucleoside
Nucleosides are glycosylamines that can be thought of as nucleotides without a phosphate group. A nucleoside consists simply of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (ribose or 2'-deoxyribose) whereas a nucleotide ...
derived from
xanthine
Xanthine ( or ; archaically xanthic acid; systematic name 3,7-dihydropurine-2,6-dione) is a purine base (genetics), base found in most human body tissues and fluids, as well as in other organisms. Several stimulants are derived from xanthine, incl ...
and
ribose
Ribose is a simple sugar and carbohydrate with molecular formula C5H10O5 and the linear-form composition H−(C=O)−(CHOH)4−H. The naturally-occurring form, , is a component of the ribonucleotides from which RNA is built, and so this compo ...
. It is the
biosynthetic
Biosynthesis is a multi-step, enzyme-Catalysis, catalyzed process where substrate (chemistry), substrates are converted into more complex Product (chemistry), products in living organisms. In biosynthesis, simple Chemical compound, compounds are mo ...
precursor to 7-methylxanthosine by the action of
7-methylxanthosine synthase
In enzymology, a 7-methylxanthosine synthase () is an enzyme that catalysis, catalyzes the chemical reaction
:S-adenosyl-L-methionine + xanthosine \rightleftharpoons S-adenosyl-L-homocysteine + 7-methylxanthosine
Thus, the two substrate (biochemi ...
. 7-Methylxanthosine in turn is the precursor to
theobromine
Theobromine, also known as xantheose, is the principal alkaloid of '' Theobroma cacao'' (cacao plant). Theobromine is slightly water-soluble (330 mg/L) with a bitter taste. In industry, theobromine is used as an additive and precursor to ...
(active alkaloid in chocolate), which in turn is the precursor to
caffeine
Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is mainly used recreationally as a cognitive enhancer, increasing alertness and attentional performance. Caffeine acts by blocking binding of adenosine t ...
, the alkaloid in coffee and tea.
See also
*
Xanthosine monophosphate
Xanthosine monophosphate also called Xanthylate is an intermediate in purine metabolism. It is a ribonucleoside monophosphate. It is formed from IMP via the action of IMP dehydrogenase, and it forms GMP via the action of GMP synthase. Also, XMP can ...
* Xanthosine diphosphate
*
Xanthosine triphosphate
Xanthosine 5'-triphosphate (XTP) is a nucleotide that is not produced by - and has no known function in - living cells. Uses of XTP are, in general, limited to experimental procedures on enzymes that bind other nucleotides. Deamination of purine b ...
References
Nucleosides
Xanthines
{{Alkaloid-stub