Alois Pískala

Antiviral activity of triazine analogues of 1-(S)-[3-hydroxy-2-(phosphonomethoxy)propyl]cytosine (cidofovir) and related compounds.

Treatment of 5-azacytosine sodium salt with diisopropyl [(2-chloroethoxy)methyl]phosphonate followed by removal of ester groups with BrSi(CH3)3 afforded 1-[2-(phosphonomethoxy)ethyl]-5-azacytosine (3). Reaction of 5-azacytosine with [(trityloxy)methyl]-(2S)-oxirane followed by etherification with diisopropyl (bromomethyl)phosphonate and removal of ester groups gave 1-(S)-[3-hydroxy-2-(phosphonomethoxy)propyl]-5-azacytosine (1). The synthesis of 6-azacytosine congener 2 was analogous using N4-benzoylated intermediates. Compound 1 was shown to exert strong activity against a broad spectrum of DNA viruses including adenoviruses, poxviruses, and herpesviruses (i.e., herpes simplex viruses, varicella zoster virus, and human cytomegalovirus). Decomposition of 1 in alkaline solutions resulted in products 17 and 18. While the N-formylguanidine derivative 17 proved active, the carbamyolguanidine derivative 18 was devoid of antiviral activity.

Synthesis and antiviral evaluation of N-β-D-ribosides of ergot alkaloids

Abstract N-β-D-Ribosides of agroclavine (1), elymoclavine (2), lysergene (4), lysergol (3), and 9, 10-dihydrolysergol (5) were prepared by SnCl4 catalyzed ribosylation of their TMS derivatives with 1-O-acetyl-2, 3,5-tri-O-benzoyl-β-D-ribofuranose. None of the new compounds exhibited activity against HIV or other viruses tested.

6-Methyl-5-Azacytidine-Synthesis, Conformational Properties and Biological Activity. A Comparison of Molecular Conformation with 5-Azacytidine

Abstract The title compound was prepared by the isocyanate procedure and the tri-methylsilyl method. The measurement of 1H NMR spectrum of 6-methyl-5-azacytidine (1) revealed a preference of γt (46%) rotamer around C(5′)-C(4′) bond, a predominance of N conformation of the ribose ring (Keq 0.33) and a preference of syn conformation around the C-N glycosyl bond. An analogous measurement of 5-azacytidine has shown a preference of γ+ (60%) rotamer around the C(5′)-C(4′) bond, a predominance of N conformation of the ribose ring (Keq 0.41) and a preference of anti conformation around the C-N glycosyl bond. 6-Methyl-5-azacytidine (1) inhibits the growth of bacteria E. coli to the extent of 85% at 4000 μM concentration and the growth of LoVo/L, a human colon carcinoma cell line, to the extent of 30% at 100 μM concentration but did not inhibit L1210 cells at ≤ 100 μM concentration. 6-Methyl-5-azacytidine (1) exhibited no in vitro antiviral activity at ≤ 1 μM concentration. + Present address: Beckman, 2500 Harbor B...