AT-9010 (2'-methyl-2'-fluoro guanosine triphosphate) is a GTP analog whose prodrug, AT-752 is under consideration in human medicine as a potential antiviral drug against certain flaviviruses. It was previously believed to inhibit viral replication by acting primarily as a chain terminator. However, it was discovered recently that it also binds the GTP binding site of the methyltransferase (MTase) domain of the orthoflavivirus polymerase, thus interfering with RNA capping. Here, we investigated the binding of AT-9010 to Ntaya and Zika virus MTases. Structural analysis using X-ray crystallography revealed similar interactions between the base and sugar moieties of AT-9010 and key residues in both MTases, although differences in hydrogen bonding were observed. Our analysis also suggested that the triphosphate part of AT-9010 is flexible. Despite minor variations, the overall binding mode of AT-9010 was found to be the same for all of the flaviviral MTases examined, suggesting a structural basis for the efficacy of AT-9010 against multiple orthoflavivirus MTases.

• MeSH
• antivirové látky * chemie   farmakologie   metabolismus   MeSH
• Flaviviridae * enzymologie   MeSH
• guanosintrifosfát * analogy a deriváty   metabolismus   chemie   MeSH
• krystalografie rentgenová MeSH
• lidé MeSH
• methyltransferasy * metabolismus   chemie   genetika   MeSH
• molekulární modely MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• virové proteiny * metabolismus   chemie   MeSH
• virus zika * enzymologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antivirové látky * MeSH
• guanosintrifosfát * MeSH
• methyltransferasy * MeSH
• virové proteiny * MeSH

Cyclic dinucleotides (CDNs) are second messengers that activate stimulator of interferon genes (STING). The cGAS-STING pathway plays a promising role in cancer immunotherapy. Here, we describe the synthesis of CDNs containing 7-substituted 7-deazapurine moiety. We used mouse cyclic GMP-AMP synthase and bacterial dinucleotide synthases for the enzymatic synthesis of CDNs. Alternatively, 7-(het)aryl 7-deazapurine CDNs were prepared by Suzuki-Miyaura cross-couplings. New CDNs were tested in biochemical and cell-based assays for their affinity to human STING. Eight CDNs showed better activity than 2'3'-cGAMP, the natural ligand of STING. The effect on cytokine and chemokine induction was also evaluated. The best activities were observed for CDNs bearing large aromatic substituents that point above the CDN molecule. We solved four X-ray structures of complexes of new CDNs with human STING. We observed π-π stacking interactions between the aromatic substituents and Tyr240 that are involved in the stabilization of CDN-STING complexes.

• MeSH
• cytokiny MeSH
• interferony MeSH
• lidé MeSH
• ligandy MeSH
• membránové proteiny * metabolismus   MeSH
• myši MeSH
• nukleotidy cyklické * chemie   MeSH
• nukleotidyltransferasy MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 7-deazapurine MeSH Prohlížeč
• cytokiny MeSH
• interferony MeSH
• ligandy MeSH
• membránové proteiny * MeSH
• nukleotidy cyklické * MeSH
• nukleotidyltransferasy MeSH

A new approach for synthesizing polycyclic heterofused 7-deazapurine heterocycles and the corresponding nucleosides was developed based on C-H functionalization of diverse (hetero)aromatics with dibenzothiophene-S-oxide followed by the Negishi cross-cooupling with bis(4,6-dichloropyrimidin-5-yl)zinc. This cross-coupling afforded a series of (het)aryl-pyrimidines that were converted to fused deazapurine heterocycles through azidation and thermal cyclization. The fused heterocycles were glycosylated to the corresponding 2'-deoxy- and ribonucleosides, and a series of derivatives were prepared by nucleophilic substitutions at position 4. Four series of new polycyclic thieno-fused 7-deazapurine nucleosides were synthesized using this strategy. Most of the deoxyribonucleosides showed good cytotoxic activity, especially for the CCRF-CEM cell line. Phenyl- and thienyl-substituted thieno-fused 7-deazapurine nucleosides were fluorescent, and the former one was converted to 2'-deoxyribonucleoside triphosphate for enzymatic synthesis of labeled oligonucleotides.

• MeSH
• deoxyribonukleosidy MeSH
• nádorové buněčné linie MeSH
• nukleosidy * MeSH
• oligonukleotidy MeSH
• oxidy MeSH
• purinové nukleosidy MeSH
• pyrimidiny MeSH
• ribonukleosidy * MeSH
• zinek MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 7-deazapurine MeSH Prohlížeč
• deoxyribonukleosidy MeSH
• nukleosidy * MeSH
• oligonukleotidy MeSH
• oxidy MeSH
• purinové nukleosidy MeSH
• pyrimidiny MeSH
• ribonukleosidy * MeSH
• zinek MeSH

d-Arabinofuranosyl-pyrimidine and -purine nucleoside analogues containing alkylthio-, acetylthio- or 1-thiosugar substituents at the C2' position were prepared from the corresponding 3',5'-O-silylene acetal-protected nucleoside 2'-exomethylenes by photoinitiated, radical-mediated hydrothiolation reactions. Although the stereochemical outcome of the hydrothiolation depended on the structure of both the thiol and the furanoside aglycone, in general, high d-arabino selectivity was obtained. The cytotoxic effect of the arabinonucleosides was studied on tumorous SCC (mouse squamous cell) and immortalized control HaCaT (human keratinocyte) cell lines by MTT assay. Three pyrimidine nucleosides containing C2'-butylsulfanylmethyl or -acetylthiomethyl groups showed promising cytotoxicity at low micromolar concentrations with good selectivity towards tumor cells. SAR analysis using a methyl β-d-arabinofuranoside reference compound showed that the silyl-protecting group, the nucleobase and the corresponding C2' substituent are crucial for the cell growth inhibitory activity. The effects of the three most active nucleoside analogues on parameters indicative of cytotoxicity, such as cell size, division time and cell generation time, were investigated by near-infrared live cell imaging, which showed that the 2'-acetylthiomethyluridine derivative induced the most significant functional and morphological changes. Some nucleoside analogues also exerted anti-SARS-CoV-2 and/or anti-HCoV-229E activity with low micromolar EC50 values; however, the antiviral activity was always accompanied by significant cytotoxicity.

• Klíčová slova
• SARS-CoV-2, anti-tumor, antiviral, coronavirus, nucleoside analogue, photocatalytic thiol-ene reaction, time-lapse imaging,
• MeSH
• acetaly MeSH
• antivirové látky farmakologie   MeSH
• arabinonukleosidy chemie   farmakologie   MeSH
• COVID-19 * MeSH
• lidé MeSH
• myši MeSH
• nukleosidy farmakologie   chemie   MeSH
• puriny MeSH
• pyrimidinové nukleosidy * MeSH
• sulfhydrylové sloučeniny chemie   MeSH
• thiosacharidy * MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetaly MeSH
• antivirové látky MeSH
• arabinonukleosidy MeSH
• nukleosidy MeSH
• puriny MeSH
• pyrimidinové nukleosidy * MeSH
• sulfhydrylové sloučeniny MeSH
• thiosacharidy * MeSH