Purines and Pyrimidine Derivatives

<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 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 A labelled metabolite of Allopurinol.<br>References Marro, P., et al.: Brain Res., 650, 9 (1994), Abramov, A., et al.: J. Neurosci., 27, 1129 (2007), Day, R., et al.: Clin. Pharmacokinet., 46, 623 (2007),<br></p>

<p>Applications Caffeine-d3 (1-methyl-d3) (CAS# 26351-03-1) is a useful isotopically labeled research compound.<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 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>