Title: Xanthosine
CAS Registry Number: 146-80-5
Additional Names: Xanthine riboside; 9-b-D-ribofuranosyl xanthine; 9-b-D-ribofuranosyl-9H-purine-2,6-diol; 9-b-D-ribofuranosyl-9H-purine-2,6-(1H,3H)-dione
Molecular Formula: C10H12N4O6
Molecular Weight: 284.23
Percent Composition: C 42.26%, H 4.26%, N 19.71%, O 33.77%
Literature References: Prepd from guanosine by treatment with sodium nitrite and acetic acid: Levene, Jacobs, Ber. 43, 3163 (1910); Gulland, Macrae, J. Chem. Soc. 1933, 662. Synthesis: Howard et al., ibid. 1949, 232. Biosynthesis: Magasanik, Brooke, J. Biol. Chem. 206, 83 (1954); Korn, Buchanan, ibid. 217, 183 (1955); Bolis et al., ibid. 219, 917 (1956).
Derivative Type: Dihydrate
Properties: Long prisms from water. Anhydr felted clusters (warts) from alc. Dec on heating, no distinct melting range. [a]D30 -51.2° (p = 8 in 0.3N NaOH). uv max: 253 nm (e 8.790). aM (molar absorbancy): 11.4´103 at 248.5 nm in water at pH 8.0. Sparingly sol in cold water; freely sol in hot water; sol in hot dil alcohol. Easily hydrolyzed by mineral acids.
Optical Rotation: [a]D30 -51.2° (p = 8 in 0.3N NaOH)
Absorption maximum: uv max: 253 nm (e 8.790)
Xanthoxyletin Xanthoxylin Xanthurenic Acid Xanthyletin Xemilofiban

CAS number 146-80-5 YesY
PubChem 64959
ChemSpider 58484 N
Jmol-3D images Image 1
Molecular formula C10H12N4O6
Molar mass 284.23 g mol−1
Melting point Decomposes when heated
Solubility in water Sparingly soluble in cold water; freely soluble in hot water
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Xanthosine is a nucleoside derived from xanthine and ribose. It is the biosynthetic precursor to 7-methylxanthosine by the action of 7-methylxanthosine synthase. 7-Methylxanthosine in turn in the precursor to theobromine (active alkaloid in chocolate), which in turn is the precursor to caffeine, the alkaloid in coffee and tea.[2]