Derivados de Purinas e Pirimidinas

<p>Applications Nicotinic Acid-13C6 is labelled Nicotinic acid. It is a precursor of the coenzymes NAD and NADP. Widely distributed in nature; appreciable amounts are found in liver , fish, yeast and cereal grains. Dietary deficiency is associated with pellagra. The term “niacin” has also been applied to nicotinamide or to other derivatives exhibiting the biological activity of nicotinic acid. Vitamin (enzyme cofactor).<br>References Darby, W.J., et al.: Nutr. Rev., 33, 289 (1975), Black, A., et al.: Eur. J. Clin. Nutr., 54, 395 (2000), Cole, T., et al.: Br. Med. J., 320, 1240 (2000), Forshee, R., et al.: J. Nutr., 134, 2733 (2004),<br></p>

<p>Stability Hygroscopic<br>Applications Dihydro Caffeic Acid 3-O-β-D-Glucuronide is a glucuronide metabolite of Caffeic Acid (C080000).<br>References Clifford, M., et al.: J .Agric. Food Chem., 53, 3821 (2005), Lafay, S., et al.: J. Nutr., 136, 1192 (2006), Poquet, L., et al.: Drug Metab. Dispos., 36, 190 (2008)<br></p>

<p>Stability Hygroscopic<br>Applications Methotrexate Diglutamate is a metabolite of Methotrexate (M260675); a folic acid antagonist, antineoplastic, and antirheumatic.<br>References Freeman, M.V., J. Pharmacol. Exp. Ther., 122, 154 (1958); Weinblass, M.E., et al.: N. Engl. J. Med., 312, 818 (1985)<br></p>

<p>Applications Caffeine-13C is carbon-13 labeled Caffeine (C080100). Caffeine is a bitter, white crystalline xanthine alkaloid that acts as a stimulant drug and a reversible acetylcholinesterase inhibitor. Caffeine is found in varying quantities in the seeds, leaves, and fruit of some plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants. In humans, caffeine acts as a central nervous system stimulant, temporarily warding off drowsiness and restoring alertness. Caffeine is a cardiac and respiratory stimulant; diuretic. Caffeine is toxic at sufficiently high doses.A study at Johns Hopkins University indicates that caffeine can improve pattern separation memory.<br> Not a dangerous good if item is equal to or less than 1g/ml and there is less than 100g/ml in the package<br>References Zubair, U.M., et al.: Anal. Profiles Drug Subs., 15, 71 (1986); Cherrah, Y., et al.: Biochem. Pharmacol., 37, 1311 (1988);  Chem. and Eng. News p.34, Jan. 20, (2014)<br></p>

<p>Applications 9-(2-Propenyl)adenine is an N-substituted purine used in the preparation of mesityl dihydroisoxazolyl homo-N-nucleosides.<br>References Thalassitis, A. et al.: Bioorg. Med. Chem. Lett., 19, 6433 (2009); Chiacchio, U. et al.: Tetrahedron, 60, 441 (2004)<br></p>

<p>Applications Labelled analogue of L-Phenylalanine, an essential amino acid. L-Phenylalanine is biologically converted into L-tyrosine, another one of the DNA-encoded amino acids, which in turn is converted to L-DOPA and further converted into dopamine, norepinephrine, and epinephrine. L-Phenylalanine is produced for medical, feed, and nutritional applications such as in the preparation of Aspartame.<br>References Hollunger, G. et al.: Acta Pharmacol. Toxicol., 34, 391 (1974); Bagchi, S.P. et al.: Biochem. Pharmacol., 26, 900 (1977);<br></p>

<p>Xanthine, a purine breakdown product, is turned into uric acid by xanthine oxidase and blocks adenosine receptors.</p>

<p>Applications 1,3,7-Trimethyluric Acid is a caffeine derivative, and a methyl derivative of uric acid. Detected as a urine marker of caffeine consumption.<br>References Rothwell, J. et al.: PLoS One, 9, e93474 (2014); Silva, C. et al.: Sci. Trans. Med., 5, 197ra04 (2013);<br></p>

<p>Applications 3-Oxobutanoic Acid Methyl Ester is a chemical reagent used in the synthesis of pharmaceuticals. It participates in the Biginelli reaction, forming molecules including dihydropyrimidinones.<br>References Ranu, B. et al.: J. Org. Chem. 65, 6270 (2000); Lu, J. et al.: Tetrahedron Lett., 41, 9075 (2000); Lu, J. et al.: Synlett., 1, 63 (2000);<br></p>

<p>Applications The essential intermediate metabolite from which the active metabolite of Clopidogel is formed.<br>References Feliste, R., et al.: Thromb. Res., 48, 403 (1987), Savi, P., et al.: Biochem. Pharmacol., 44, 527 (1992), Herbert, J., et al.: Cardiovasc Drug. Rev., 11, 180 (1993), Sugidachi, A., et al.: B. J. Pharmacol., 132, 47 (2001)<br></p>

<p>Applications Tenofovir Alafenamide Fumarate is a prodrug of Tenofovir (T018500), which is a reverse transcriptase inhibitor used to treat HIV and Hepatitis B. Antiviral.<br>References Shaw, J.-P., et al.: Pharm. Res., 14, 1824 (1997), Wyles, D., et al.: Clin Infect. Dis., 40, 174 (2005), Peng, J., et al.: J. Clin. Pharmacol., 46, 265 (2006), Seminari, E., et al.: J. Antimicrob. Chemother., 60, 831 (2007),<br></p>

<p>Applications Intermediate in the preparation of Pemetrexed.<br></p>