Derivados de Purinas y Pirimidinas

<p>Applications (S)-Tenofovir is an S-enatiomeric derivative of Tenofovir (T018500). (S)-Tenofovir displays virucidal activity against herpes, visna virus and retrovirus. The S enantiomer of Tenofovir (T018500) is less effective against HIV than their (R)-enantiomeric counterparts.<br>References Balzarini, J. et al: Biochem. Biophys. Res. Comm., 219, 337 (1996); Balzarini, J. et al.: Antimicrob. Agents. Ch., 37, 332 (1993); Thormar, H. et al.: Antimicorb. Agents. Ch., 37, 2540 (1993)<br></p>

<p>Applications Sulbutiamine (isobutyryl thiamine disulfide) is a lipophilic derivative of thiamine used for the treatment of asthenia and other related pathological conditions. Sulbutiamine is available over-the-counter in several countries as a component of nutritional supplements.<br>References Micheau, J., et al.: Pharmacol. Biochem. Behav., 23, 195 (1985), Bettendorff, L., et al.: Biochem. Pharmacol., 40, 2557 (1990), van Reeth, O., et al.: Drugs Today, 35, 187 (1999),<br></p>

<p>Stability Very Hygroscopic<br>Applications A product of the extracellular Nicotinamide phosphoribosyltransferase (eNAMPT) reaction and a key NAD+ intermediate. It ameliorates glucose intolerance by restoring NAD+ levels in HFD-induced T2D mice. It also enhances hepatic insulin sensitivity and restores gene expression related to oxidative stress, inflammatory response, and circadian rhythm, partly through SIRT1 activation.<br>References Yoshino, J. et al.: Cell Metab., 14, 528 (2011); Caton, P.W. et al.: Diabetologia, 54, 3083 (2011); Formentini, L. et al.: BIochem. Pharmacol., 77, 1612 (2009);<br></p>

<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 Labelled nucleoside analog; specific inhibitor of hepatitis B virus (HBV) replication. Antiviral.<br>References Standring, D.N., et al.: Antiviral. Chem. Chemother., 12, 119 (2001), Hernandez-Santiago, B., et al.: Antimicrob. Agents Chemother., 46, 1728 (2002), Lai, C.-L., et al.: Hepatology, 40, 719 (2004), Han, S.-H.B., et al.: Expert Opin. Invest. Drugs, 14, 511 (2005),<br></p>

<p>Applications 2,2,2-Trichloro-acetic Acid is an acetic acid analogue used for the precipitation of macromolecules including proteins, DNA and RNA as well as for cosmetic treatments.<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 Wiley D. et al.: Clin. Infect. Dis., 35m S210 (2002);<br></p>

<p>Impurity Naratriptan pyridinium Impurity<br>Stability Hygroscopic<br>Applications Naratriptan (N378730) impurity.<br></p>

<p>Applications A metabolite of Nitrotyrosine (N597000), which is excreted in the urine.<br>References van der Vliet, A., et al.: J. Biol. Chem., 272, 7617 (1997), Tabrizi-Fard, M., et al.: Drug Metab. Dispos., 27, 429 (1999), Souza, J., et al.: Arch. Biochem. Biophys., 380, 360 (2000),<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>Applications Caffeine-d3 (1-methyl-d3) (CAS# 26351-03-1) is a useful isotopically labeled research compound.<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>Stability Hygroscopic<br>Applications It is a potent and selective inhibitor of bacterial dihydrofolate reductase, the enzyme responsible for the NADPH-dependent reduction of 7,8-dihydrofolate to 5,6,7,8-tetrahydrofolate. Antibacterial.This compound is a contaminant of emerging concern (CECs).<br>References Manius, G.J., et al.: Anal. Profiles Drug Subs., 7, 445 (1978), Roth, B., et al.: J. Med. Chem., 23, 379 (1980), Brogden, R.N., et al.: Drugs, 23, 405 (1982),<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>