Synthesis and biological evaluation of furopyrimidine N,O-nucleosides

Expression of Tissue Transglutaminase in Human Thyroid Cancer Cell Lines: Effect of Novel Enantiopure Triazole Derivatives

“…The resulting solution was evaporated under vacuum, and the residue was purified by MPLC (CH2Cl2/MeOH, 98:2) to afford enantiopure (-)5b and (-)6d in 40 and 45% yield respectively. The NMR spectra and elemental analysis were identical with the literature data [53]. …”

“…In preliminary experiments, a lot of the both cell cultures were exposed to different concentrations of synthesized triazole derivatives (-)5b and (-)6d [53] (0.5, 1, 5, 10, 25, 50, 100 µM) for 12, 24, 48 hr, in order to establish the optimal concentrations and their exposure times to the triazole derivates [28,62,63]. For this purpose, MTT test and morphological characterization were utilized [30].…”

“…The enantiomeric excesses and substrate conversions were determined by chiral HPLC analysis using a Chiralcel ® OJ (Daicel Chemical Industries) column. C-[(tert-butyldiphenylsilyl)oxy]-Nmethyl nitrone1, vinyl triazoles 2b,d, and racemic 5b and 6d were prepared according to the methods described in literature [53].…”

5-(3-Phosphonated 1H-1,2,3-triazol-4-yl)isoxazolidines: synthesis, DFT studies and biological properties

“…[5][6] In particular, N,O-nucleosides, characterized by the presence of an isoxazolidine system as mimetic of the ribose spacer, have been designed and shown to be endowed with antiviral and/or antitumoral activity. [7][8][9][10][11][12][13] PCOANS 1 have shown to be potent inhibitors of reverse trascriptase (RT) of different retroviruses; [14][15][16][17] Structural modifications concerning the purine or pyrimidine nucleobases have also been investigated [19][20] and shown to led to biologically interesting compounds. In particular, the use of unnatural heterocycles as nucleobases in the design of novel nucleoside analogues not only enhances the in vivo stability of the obtained compounds, but also confers novel mechanisms of action.…”

Nanotechnology Approaches for Antiretroviral Drugs Delivery

“…After incorporation, these nucleoside analogues inhibit the elongation of viral DNA chain, preventing the incorporation of next incoming nucleotide, resulting in termination of the growing viral DNA chain [30]. In the last year, to search new biologically active nucleoside analogues, structural modifications on the sugar moiety and/ or the heterocyclic base of natural nucleosides have been performed in order to overcome the drawbacks mainly due to enzymatic degradation and/or to reduce the toxicity and the cross-resistance problems [31][32][33][34][35][36][37][38][39][40]. Currently, there are eight FDA-approved NRTIs: abacavir (ABC), didanosine (ddI), emtricitabine (FTC), lamivudine (3TC), stavudine (d4T), zalcitabine (ddC), zidovudine (AZT), and tenofovir disoprovil fumarate (TDF), a nucleotide RT inhibitor (Figure1).…”