Synthesis of a 6-methyl-7-deaza analogue of adenosine that potently inhibits replication of polio and dengue viruses

Bioisosteric deaza analogues of 6-methyl-9-β-D-ribofuranosylpurine, a hydrophobic analogue of adenosine, were synthesized and evaluated for antiviral activity. Whereas the 1-deaza and 3-deaza analogues were essentially inactive in plaque assays of infectivity, a novel 7-deaza-6-methyl-9-β-D-ribofuranosylpurine analogue, structurally related to the natural product tubercidin, potently inhibited replication of poliovirus (PV) in HeLa cells (IC(50) = 11 nM) and dengue virus (DENV) in Vero cells (IC(50) = 62 nM). Selectivity against PV over cytotoxic effects to HeLa cells was >100-fold after incubation for 7 h. Mechanistic studies of the 5'-triphosphate of 7-deaza-6-methyl-9-β-D-ribofuranosylpurine revealed that this compound is an efficient substrate of PV RNA-dependent RNA polymerase (RdRP) and is incorporated into RNA mimicking both ATP and GTP.

Total Synthesis of 4-Acetyl-1,3-Dihydroimidazo[4,5-c]Pyridin-2-One, a New Microbial Metabolite from a Streptomyces Species

The structure of a new secondary metabolite from Streptomyces sp. was determined as 4-acetyl-1,3-dihydroimidazo[4,5-c]pyridin-2-one by synthesis of the natural product itself and of the regioisomeric 7-acetylimidazo[4,5-b]pyridine derivative. The former compound was prepared, in 28% overall yield, in a sequence of nitration, reduction, condensation, and Stille reaction of 4-aminopyridine, while the regioisomer was obtained in 5% overall yield by amination, nitration, reduction, condensation, and oxidation of 4-ethylpyridine.

Synthesis of (aryloxyacetylamino)-isonicotinic/nicotinic acid analogues as potent hypoxia-inducible factor (HIF)-1α inhibitors

We report a new series of HIF-1alpha inhibitors which were obtained through structural modifications of previously reported lead 1. The in vitro inhibitory potencies of newly synthesized compounds were evaluated against hypoxia-induced HIF-1 activation using cell-based reporter assay in three human cancer cell lines including SK-Hep-1, Hep3B, and AGS cells. Several compounds displayed significant inhibitory activity in all the three tested cell lines. In particular, analogue 17 displayed potent inhibition of hypoxia-induced accumulation of HIF-1alpha protein in Hep3B cell line, in addition to the dose-dependent inhibition of HIF-1 target genes VEGF and EPO.

Synthesis of 3-deaza-3-nitro-2′-deoxyadenosine

Photoactivable deoxyadenosine mimic, 3-deaza-3-nitro-2'-deoxyadenosine (2), was prepared using two different synthetic routes. The first route involved base catalyzed glycosylation of 3-deaza-3-nitroadenine, which was prepared by regioselective nitration of 3-deazaadenine. In the second route, the convertible nucleoside 6-O-(2,4,6-trimethylphenyl)-3-deaza-2'-deoxyadenosine (28) was used to introduce 6-NH2 group in the last step.

L-deaza-5'-noraisteromycin

(+/-)-1-Deazaaristeromycin (4) has been reported to be an inactivator of S-adenosylhomocysteine (AdoHcy) hydrolase and, as a consequence, to affect S-adenosylmethionine (AdoMet) mediated macromolecular biomethylations. To extend this to our program focused on 5'-noraristeromycin derivatives as inhibitors of the same hydrolase enzyme as potential antiviral agents, both enantiomers of 1-deaza-5'-noraristeromycin (5 and 20) have been prepared. Compounds 5 and 20 were evaluated against the following viruses: vaccinia, cowpox, monkeypox, Ebola, herpes simplex type 1 and 2, human cytomegalovirus, Epstein Barr, varicella zoster, hepatitis B, hepatitis C, HIV-1 and HIV-2, adenovirus type 1, measles, Pichinde, parainfluenza type 3, influenza A (H1N1 and H3N2), influenza B, Venezuelan equine encephalitis, rhinovirus type 2, respiratory syncytial, yellow fever, and West Nile. No activity was found nor was there any cytotoxicity to the viral host cells.