Nucleotide Substrate Specificity of Anti-Hepatitis C Virus Nucleoside Analogs for Human Mitochondrial RNA Polymerase.

Nucleoside analog inhibitors (NAIs) are an important class of antiviral agents. Although highly effective, some NAIs with activity against hepatitis C virus (HCV) can cause toxicity, presumably due to off-target inhibition of host mitochondrial RNA polymerase (POLRMT). The nucleotide substrate specificity of POLRMT was studied in order to explore structure-activity relationships that can facilitate the identification of nontoxic NAIs.

Biochemical Characterization of the Active Anti-Hepatitis C Virus Metabolites of 2,6-Diaminopurine Ribonucleoside Prodrug Compared to Sofosbuvir and BMS-986094.

Ribonucleoside analog inhibitors (rNAI) target the hepatitis C virus (HCV) RNA-dependent RNA polymerase nonstructural protein 5B (NS5B) and cause RNA chain termination. Here, we expand our studies on β-d-2'-C-methyl-2,6-diaminopurine-ribonucleotide (DAPN) phosphoramidate prodrug 1 (PD1) as a novel investigational inhibitor of HCV. DAPN-PD1 is metabolized intracellularly into two distinct bioactive nucleoside triphosphate (TP) analogs.

Discovery of a nanomolar inhibitor of lung adenocarcinoma in vitro.

Efficient methods for the preparation of 5'-substituted 5'-amino-5'-deoxy-N(6)-ureidoadenosine derivatives are described. Compounds were screened for antiproliferative activity against a panel of murine and human cell lines (L1210, CEM, and HeLa) and/or against the NCI-60. The most potent derivative inhibited the lung adenocarcinoma cell line NCI-H522 at low nanomolar concentrations (GI50 = 9.

Chutes and ladders in hepatitis C nucleoside drug development.

Chutes and Ladders is an exciting up-and-down-again game in which players race to be the first to the top of the board. Along the way, they will find ladders to help them advance, and chutes that will cause them to move backwards. The development of nucleoside analogs for clinical treatment of hepatitis C presents a similar scenario in which taking shortcuts may help quickly advance a program, but there is always a tremendous risk of being sent backwards as one competes for the finish line.

Synthesis and SAR of 2',3'-bis-O-substituted N(6), 5'-bis-ureidoadenosine derivatives: implications for prodrug delivery and mechanism of action.

A series of 2',3'-bis-O-silylated or -acylated derivatives of lead compound 3a (2',3'-bis-O-tert-butyldimethylsilyl-5'-deoxy-5'-(N-methylcarbamoyl)amino-N(6)-(N-phenylcarbamoyl)adenosine) were prepared and evaluated for antiproliferative activity against a panel of murine and human cancer cell lines (L1210, FM3A, CEM, and HeLa). 2',3'-O-Silyl groups investigated included triethylsilyl (10a), tert-butyldiphenylsilyl (10b), and triisopropylsilyl (10c). 2',3'-O-Acyl groups investigated included acetyl (13a), benzoyl (13b), isobutyryl (13c), butanoyl (13d), pivaloyl (13e), hexanoyl (13f), octanoyl (13g), decanoyl (13h), and hexadecanoyl (13i).

Synthesis, SAR, and preliminary mechanistic evaluation of novel antiproliferative N⁶,5'-bis-ureido- and 5'-carbamoyl-N⁶-ureidoadenosine derivatives.

We have developed efficient methods for the preparation of N(6),5'-bis-ureidoadenosine derivatives and their 5'-carbamoyl-N(6)-ureido congeners. Treatment of 5'-azido-5'-deoxy-N(6)-(N-alkyl or -arylurea)adenosine derivatives (6a-d) with H(2)/Pd-C or Ph(3)P/H(2)O, followed by N-methyl-p-nitrophenylcarbamate gave N(6),5'-bis-ureido products 7a-d in 49-78% yield. Analogous derivatives in the 5'-carbamoyl-N(6)-ureido series were prepared by treatment of 2',3'-bis-O-TBS-adenosine (11) with N-methyl-p-nitrophenylcarbamate followed by acylation with appropriate isocyanates which gave 13a-d in 45-69% yield.

A broad spectrum anticancer nucleoside with selective toxicity against human colon cells in vitro.

2',3'-Bis-O-tert-butyldimethylsilyl-5'-deoxy-5'-[N-(methylcarbamoyl)amino]-N(6)-(N-phenylcarbamoyl)adenosine, a new member of the N(6),5'-bis-ureidoadenosine class of anticancer nucleosides, is found to exhibit broad spectrum antiproliferative activity. A majority of the cell lines in the NCI-60 are inhibited with an average GI(50)=3.13 μM.