Derivados de Purinas e Pirimidinas

<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 An adenosine deaminase inhibitor used as an anti-cancer therapeutic drug. Shown to be effective in the treatment of hairy cell leukemia as well as having use in the treatment of other types of cancer such as chronic lymphocytic leukemia.<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 Rogler-Brown, T. et al.: Biochem. Pharmacol., 28, 201 (1979); Johnston, J.B. et al.: J. Natl. Canvcer Inst., 80, 765 (1988); Fortune, A.F. et al.: Leuk. and Lymph., 51, 839 (2010); Robak, T. et al.: Drugs, 69, 2415 (2009);<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>Applications Used in the biological study of differentiation induced by nicotinic acid, nicotinamide and isonicotinic acid in human leukemia cell lines.<br>References Zeilinger, S., et al.: J. Biol. Chem., 271, 25624 (1996), Panagiotou, G., et al.: J. Biotechnol., 118, 304 (2005),<br></p>

<p>Applications L-Aspartyl-L-phenylalanine is an impurity of Thiamine (T344185). Thiamine Impurity B.<br>References Aluwihare, L., et al.: Science, 308, 1007 (2005), Koch, B., et al.: Anal. Chem., 79, 1758 (2007), Reemtsma, T., et al.: Environ. Sci. Technol., 42, 1430 (2008),<br></p>

<p>Stability Hygroscopic<br>Applications A labelled specific serotonin (5-HT3) receptor antagonist. Antiemetic.<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 Kris, M.G., et al.: J. Clin. Oncol., 6, 659 (1988), Faris, P..L., et al.: Lances, 355, 792 (2000),<br></p>

<p>Applications An intermediate in the biosynthesis of Heme, found in the urine of patients with acute porphyria.<br>References Westall, et al.: Nature, 170, 614 (1952), Cookson, R., et al.: Biochem, J., 57, 476 (1954), MacDonald, J., Can. J. Chem., 35, 715 (1957),<br></p>

<p>Applications Allopurinol is a xanthine oxidase inhibitor; decreases uric acid production. Used in treatment of hyperuricemia and chronic gout. Antiurolithic.<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 Benezra, S.A., et al.: Anal. Profiles Drug Subs., 7, 1, (1978); Dalbeth, N., et al.: Rheumatology, 44, 1090 (2005); Dinarello, C., et al.: J. Exp. Med., 201, 1355 (2005);<br></p>

<p>Applications Metabolite of 6-Mercaptopurine, an immunosuppressive drug used to treat leukemia.<br>References Chou, C., et al.: Biochem. Pharmacol., 75, 1601 (2008), Conejo-Garcia, A., et al.: Eur. J. Med. Chem., 43, 1742 (2008), Hawwa, A., et al.: Brit. J. Clin. Pharmacol., 66, 826 (2008), Askanase, A., et al.: J. Rheumatol., 36, 89 (2009),<br></p>

<p>Applications Metabolite of Caffeine (C080100).<br>References Wong, P., et al.: J. Pharm. Biomed. Anal., 28, 693 (2002), Nyeki, A., et al.: Brit. J. Clin. Pharmacol., 55, 62 (2003), Jetter, A., et al.: Eur. J. Clin. Pharmacol., 65, 411 (2009),<br></p>

<p>Applications Labelled Theophylline is a xanthine derivative with diuretic, cardiac stimulant and smooth muscle relaxant activities; isomeric with theobromine. Small amounts occur in tea. Bronchodilator.<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 Cohen, J.L., et al.: Anal. Profiles Drug Subs., 4, 466 (1975), Svedmyr, K., et al.: Allergy, 37, 111 (1982),<br></p>

<p>Applications Labelled Urea. Physiological regulator of nitrogen excretion in mammals; synthesized in the liver as an end-product of protein catabolism and excreted in urine. Also occurs normally in skin. Emollient; diuretic.<br>References Demetriou, A., et al.: Science, 233, 1190 (1986); Aebischer, P., et al.: Nat. Med., 2, 696(1996); Prakash, S., et al.: Biotechnol. Bioeng., 46, 621(1995);<br></p>

<p>Applications 5-Methyl-3-methylene-2-hexanone is an impurity of Tetrabenazine (T284000), an antipsychotic.<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 Brossi, A., et al.: Helv. Chim. Acta, 43, 583 (1960);<br></p>

<p>Applications 4-(3-Bromo-4-oxobutyl)benzoic Acid Methyl Ester is used as a reagent in the synthesis of furoxanoxyalkyl esters of pemetrexed as antifolates and nitric oxide donors for use as anticancer agents and their activities against four human cancer cell lines.<br>References Min, T., et al.: Med. Chem. Res., 18, 495 (2009); Barnett, C.J., et al.: Org. Process Res. Dev., 3, 184 (1999)<br></p>

<p>Impurity Methotrexate EP Impurity B<br>Applications Aminopterin (Methotrexate EP Impurity B) is a folic acid antagonist. Its actively transported into cells by thefolate transporter. In the cell, its converted to a high molecular weight polyglutamate metabolite by folylpolyglutamate synthase, that, in turn, binds to dihydrofolate reductase and inhibits its activity.<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 Matherly, L.H., et al.: Cancer Res., 45, 1073 (1985), Rumberger, B.G., et al.: Cancer Res., 50, 4639 (1990), Roy, K., et al.: J. Biol. Chem., 273, 2526 (1998),<br></p>

<p>Applications Succinimide is a reagent that is used in the synthesis of Lumiflavin (L473900), which is a toxic photolysis product of vitamin B2 (R415000).<br>References Zhao, X. et al.: Chemosphere, 63, 1116 (2006); Litke, S.V. et al.: Khim. Fiz., 10, 48 (1991); Ye, W. et al.: Guang. Yaox. Xueb., 12, 175 (1996);<br></p>

<p>Applications N-(3,4-Dimethoxyphenethyl)formamide is an impurity of Tetrabenazine (T284000), an antipsychotic.<br>References Schwartz, D., et al.: Biochem. Pharmacol., 15, 645 (1966),<br></p>

<p>Applications Perfume composition.<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 Hansen, B., et al.: Environ. Toxicol. Chem., 18, 772 (1999),<br></p>