Derivados de Purinas y Pirimidinas

<p>Impurity Methotrexate EP Impurity D<br>Applications N10-Methyl Pteroic Acid (Methotrexate EP Impurity D) is a Methotrexate (M260675) impurity D.<br>References Cramer, S., et al.: Cancer Res. 1984, 44, 1843 (1984), Hendel, J., et al.: Eur. J. Clin. Pharmacol., 26, 103 (1984),<br></p>

<p>Applications Caffeine-13C3 is a labelled analogue of Caffeine (C080100), 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>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 Isotope labelled analog of Xanthine (X499950), a substance that can be found in animal organs, yeast, patatoes, coffee beans, tea. Xanthine can be used to relax and widen certain breathing passages of the lungs. It is also found that a large number of derivatives that exhibits adenoside receptor antagonist properties.<br>References Mueller, C. et. al: Handbook Exp. Pharmacol. 200,151(2011)<br></p>

<p>Applications L-Phenyl-d5-alanine-2,3,3-d3 is an isotope labelled compound of L-Phenylalanine (P319415). L-Phenylalanine (Aspartame EP Impurity C) is 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. Neuroprotective product.<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 4-Amino-1,3-dimethyl-5-nitrosouracil is a useful building block for organic synthesis.<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 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>Stability Hygroscopic<br>Applications Methotrexate-d3 Triglutamate is the isotope labelled analog of Methotrexate Triglutamate (M260725); a metabolite of Methotrexate (M260675) which is 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 Labelled analogue of L-Phenylalanine, an essential amino acid.<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>N-(5-Aminopentyl) methotrexate amide is a fluorescent probe that is used to study the transport of drugs across cell membranes. It binds to the plasma membrane of cells and can be visualized with a fluorescence microscope. N-(5-Aminopentyl) methotrexate amide has been shown to bind to leukemia cells in murine leukemia models. It has a high affinity for drug-resistant cells, which makes it useful for studying drug resistance mechanisms. This probe can be used at nanomolar concentrations for imaging studies, as well as for measuring the uptake of drugs into cancer cells by flow cytometry.</p>

<p>4-[2'-(7''-Deazaguanine)ethyl]benzoic acid N-hydroxysuccinimide ester is a useful intermediate in the synthesis of 7''-deazaguanine, which is a key building block in the synthesis of DNA. 4-[2'-(7''-Deazaguanine)ethyl]benzoic acid N-hydroxysuccinimide ester is a versatile building block that can be used in the synthesis of complex compounds. It has been shown to react with amines, sulfonyl chlorides, and epoxides to form amides, sulfonamides, and epoxy amines respectively. The CAS number for this compound is 204257-65-8.</p>

<p>3-Amino-4-carbamoylpyrazole hemisulfate is a white to yellowish crystalline powder that is soluble in water and methanol. It is a condensation product of allopurinol and ethyl orthoformate with a molecular weight of 312.4. 3-Amino-4-carbamoylpyrazole hemisulfate can be used as an anti-inflammatory agent, but it has not been approved for medical use in the United States.</p>

<p>Pemetrexed related impurity 2 is a drug product that is an analytical impurity found in the metabolite of pemetrexed. It has been shown to be naturally occurring and is not toxic at high doses. This impurity has been synthesized as an impurity standard for HPLC. Pemetrexed related impurity 2 is used in research and development studies for drug development, such as pharmacopoeia testing for high purity standards.</p>

<p>4-[[(2,4-Diamino-6-pteridinyl)methyl]methylamino]benzoic acid is a drug with low bioavailability. It is used to treat leishmaniasis, an infection caused by the parasite Leishmania. 4-[[(2,4-Diamino-6-pteridinyl)methyl]methylamino]benzoic acid inhibits the synthesis of folic acid by blocking the enzyme dihydrofolate reductase in the bacteria. This drug also has been shown to be effective against autoimmune diseases and inflammatory bowel disease. The terminal half-life of 4-[(2,4-diamino6 pteridinyl)methyl]methylamino benzoic acid is approximately 5 hours and it can be detected in urine for up to 12 hours after administration.</p>

<p>Memantine impurity IV is a hydrolysis product of memantine. It appears as a white to off-white powder and has a molecular weight of 198.1 g/mol. Memantine impurity IV is an intermediate in the production of memantine and is therefore not used for any other purpose. The compound contains hydroxy groups, hydroxy, alcohols, and bridgehead groups which are efficient at hydrolyzing to form amino acids.</p>

<p>Tenofovir disoproxil related compound B is a peptidyl prodrug that is metabolized by esterases to tenofovir. It has been shown to be an effective agent against Mycobacterium tuberculosis and other bacterial species. Tenofovir disoproxil related compound B was also found to inhibit protein synthesis in Mycobacterium avium and Mycobacterium smegmatis, but not in Escherichia coli. This drug binds to the ribosome's 30S subunit, which blocks the binding of aminoacyl-tRNA and prevents the formation of peptide bonds. The mechanism of action for this drug is similar to that of the antibiotic erythromycin.</p>

<p>Tenofovir isoproxil monoester is a prodrug of Tenofovir, which is an antiviral drug. Tenofovir prevents the growth of HIV by interfering with the synthesis of viral DNA. The process development stage involves converting Tenofovir to its disoproxil monoester form, which has been shown to have greater antiviral activity than Tenofovir alone. This conversion process involves condensing one molecule of fumarate with two molecules of tenofovir, forming tenofovir disoproxil fumarate (TFD). TFD can be converted back to Tenofovir using hydrolysis and hydrogenation. Impurities in TFD include isopropyl tenofovir and unidentified impurities that are not present in the parent drug, tenofovir. Tenofovir Disoproxil Fumarate was also shown to be more potent than TFD and is undergoing clinical trials for</p>

<p>N-Acetylmemantine is a drug that inhibits the activity of acetylcholinesterase in the brain. It has been shown to inhibit cancer cell growth and induce apoptosis, as well as inhibit the reaction of hydrolysis of acetonitrile with hydrochloric acid in an organic solvent. N-Acetylmemantine is synthesized by heating ethylene in the presence of hydrochloric acid. The synthesis yields a white solid that consists mainly of N-acetylmethamphetamine. This drug interacts with cellular membranes, which may be due to its ability to react with cholesterol or phospholipids. The interaction leads to changes in membrane permeability, which can result in apoptosis.</p>

<p>Methotrexate dimethylamide is a research and development impurity standard with high purity. It is a synthetic drug product that can be custom synthesized to meet the needs of the customer. Methotrexate dimethylamide has been used as an analytical standard for HPLC analysis and as a natural metabolite in metabolism studies. This compound is also known as 71074-44-7, CAS No. 71074-44-7, or Metabolite.</p>

<p>Allopurinol impurity C is a product of the reaction between allopurinol and n-butyl alcohol, which occurs in the presence of sodium hydroxide solution and dimethylformamide. The reaction condition is heated to reflux for 12 hours, after which the mixture is filtered and concentrated under reduced pressure. The resultant crude product is purified by column chromatography with ethyl acetate and then recrystallized from methanol. The synthesis scheme can be found in Figure 1.</p>

<p>Ethyl 3-aminopyrazole-4-carboxylate is an anticancer drug that inhibits the growth of cancer cells by inhibiting protein synthesis. It has been shown to inhibit the activity of dpp-iv and pde5, which are enzymes involved in cellular proliferation. Ethyl 3-aminopyrazole-4-carboxylate has also been shown to have antiinflammatory properties, which may be due to inhibition of prostaglandin synthesis. <br>Ethyl 3-aminopyrazole-4-carboxylate is a multinuclear compound that reacts with nitrogen atoms from the pyrazoles to form a stable molecule. Dimethylformamide is used as a solvent for this reaction. The synthesis of ethyl 3-aminopyrazole-4-carboxylate starts with acetylation, which converts the carboxylic acid group into an acetic acid group. The acetic acid group reacts with ammonia and hydrogen cyan</p>