- Synthesis and cytotoxic activity of novel 5-substituted-1-(β-L- arabinofuranosyl) pyrimidine nucleosides
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A series of new 5-halogeno-1-(β-L-arabinofuranosyl)uracils and their cytosine analogues were synthesized by halogenation of ara-L-uridine and ara-L-cytidine, respectively. The 5-(2-thienyl) and 5-halogenothienyl derivatives of both series were also prepared in excellent yields by Stille coupling followed by halogenation. All of these syntheses were based on benzoyl-protected derivatives. In vitro cytotoxicity experiments carried out using L1210 mouse leukemia cells showed that 5-(2-thienyl)- ara-L-uridine was the most potent compound of the new compounds; the majority of the analogues were not effective up to 200 μM concentrations. Copyright Taylor and Francis Group, LLC.
- Sendula, Robert,Orban, Erika,Hudecz, Ferenc,Sagi, Gyula,Jablonkai, Istvan
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experimental part
p. 482 - 500
(2012/07/28)
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- COMPOUNDS FOR IMMUNOPOTENTIATION
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Methods of stimulating an immune response and treating patients responsive thereto with 3,4-di(1H-indol-3-yl)-1H-pyrrole-2,5-diones, staurosporine analogs, derivatized pyridazines, chromen-4-ones, indolinones, quinazolines, nucleoside analogs, and other small molecules are disclosed.
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Page/Page column 150
(2010/02/15)
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- Synthesis of 1-β-L-arabinofuranosylcytosine (β-L-Ara-C) and 2'-deoxy- 2'-methylene-β-L-cytidine (β-L-DMDC) as potential antineoplastic agents
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1-β-L-Arabinofuranosylcytosine (β-L-Ara-C, 7) and 2'-deoxy-2'-methylene- β-L-cytidine (β-L-DMDC, 14) have been synthesized via a multi-step synthesis from L-arabinose. These compounds were tested in vitro against L1210, P388, Sarcoma 180, and CEM cells, and found not to be active at a concentration up to 100 μM. β-L-Ara-C and β-L-DMDC were also tested against HSV-1 and HSV-2 and yielded ID50 values of >100 μM.
- Lin,Luo,Liu
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p. 1861 - 1870
(2007/10/02)
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- Aqueous conversion kinetics and mechanisms of ancitabine, a prodrug of the antileukemic agent cytarabine
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The kinetics of conversion of the prodrug ancitabine to the anti-cancer drug cytarabine have been studied in aqueous solutions in the pH range of 1.5-10.7, temperature range of 19.5-80.0°C, ionic strength range of 10-4 to 1.5, and in the presence of several general-base catalysts. Under all conditions ancitabine was quantitatively converted to cytarabine. The pH-rate profiles were linear with slope = 1 in alkaline pH, becoming pH independent in the region of maximum stability at pH ≤4, where buffer catalysis was found to be insignificant and k(obs) ? (1.12 x 1011 h-1)·exp {-10121 deg/T}. At 30°C, pH ≤4, it is calculated that an aqueous ancitabine solution will maintain 90% of its initial concentration for 12 d. A novel method for measuring general-base catalysis in competition with predominating a specific-base catalysis and in the presence of secondary salt effects a constant ionic strength was developed. Three mechanisms of hydrolytic prodrug conversion are proposed: nucleophilic hydroxide addition, general base-assisted nucleophilic water attack, and spontaneous water attack.
- Kirsch,Notari
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p. 896 - 902
(2007/10/02)
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- CONFORMATIONAL PARAMETERS OF THE CARBOHYDRATE MOIETIES OF α-ARABINONUCLEOSIDES
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The conformations of the sugar moieties of a number of α-D- and -L-arabinofuranosyl nucleosides in solution have been investigated, largely with the aid of a statistical procedure developed for this purpose.The overall results demonstrated the existence, for a broad range of analogs, of a two-state, conformational equilibrium, NS (or 2E3E).As between different analogs, there is a large variation in the relative populations of these two states that is related to the nature of the aglycon, the type of protecting groups on the sugar hydroxyl groups, and, to a much smaller extent, the solvent system.There is a striking correlation between the conformation of the sugar and the orientation of the exocyclic, hydroxymethyl group.Both for purine and pyrimidine nucleosides, a preponderance of the gauche-gauche rotamer of the exocyclic group is associated with the type-N state of the furanose ring, whereas, with the type-S state, the gauche-gauche rotamer population is virtually nonexistent.A comparison with X-ray diffraction data for 9-α-D-arabinofuranosyladenine demonstrated that, as for other classes of nucleosides, the solid-state conformation corresponds to one of the states participating in the equilibrium in solution.
- Ekiel, Irena,Darzynkiewicz, Edward,Shugar, David
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