Yohimbine, a natural indole alkaloid and a nonselective adrenoceptor antagonist, possesses potential benefits in treating inflammatory disorders and sepsis. Nevertheless, its broader clinical use faces challenges due to its low receptor selectivity. A structure-activity relationship study of novel yohimbine analogues identified amino esters of yohimbic acid as potent and selective ADRA2A antagonists. Specifically, amino ester 4n, in comparison to yohimbine, showed a 6-fold higher ADRA1A/ADRA2A selectivity index (SI > 556 for 4n) and a 25-fold higher ADRA2B/ADRA2A selectivity index. Compound 4n also demonstrated high plasma and microsomal stability, moderate-to-low membrane permeability determining its limited ability to cross the blood-brain barrier, and negligible toxicity on nontumor normal human dermal fibroblasts. Compound 4n represents an important complementary pharmacological tool to study the involvement of adrenoceptor subtypes in pathophysiologic conditions such as inflammation and sepsis and a novel candidate for further preclinical development to treat ADRA2A-mediated pathologies.

• MeSH
• alfa-2-adrenergní receptory - antagonisté * farmakologie   chemie   chemická syntéza   MeSH
• alfa-2-adrenergní receptory * metabolismus   MeSH
• lidé MeSH
• racionální návrh léčiv * MeSH
• vztahy mezi strukturou a aktivitou MeSH
• yohimbin * farmakologie   chemie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Purine nucleoside phosphorylase (PNP) is a well-known molecular target with potential therapeutic applications in the treatment of T-cell malignancies and/or bacterial/parasitic infections. Here, we report the design, development of synthetic methodology, and biological evaluation of a series of 30 novel PNP inhibitors based on acyclic nucleoside phosphonates bearing a 9-deazahypoxanthine nucleobase. The strongest inhibitors exhibited IC50 values as low as 19 nM (human PNP) and 4 nM (Mycobacterium tuberculosis (Mt) PNP) and highly selective cytotoxicity toward various T-lymphoblastic cell lines with CC50 values as low as 9 nM. No cytotoxic effect was observed on other cancer cell lines (HeLa S3, HL60, HepG2) or primary PBMCs for up to 10 μM. We report the first example of the PNP inhibitor exhibiting over 60-fold selectivity for the pathogenic enzyme (MtPNP) over hPNP. The results are supported by a crystallographic study of eight enzyme-inhibitor complexes and by ADMET profiling in vitro and in vivo.

• MeSH
• inhibitory enzymů * chemie   MeSH
• krystalografie MeSH
• lidé MeSH
• purinnukleosidfosforylasa * metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The secondary structure of nucleic acids containing quartets of guanines, termed G-quadruplexes, is known to regulate the transcription of many genes. Several G-quadruplexes can be formed in the HIV-1 long terminal repeat promoter region and their stabilization results in the inhibition of HIV-1 replication. Here, we identified helquat-based compounds as a new class of anti-HIV-1 inhibitors that inhibit HIV-1 replication at the stage of reverse transcription and provirus expression. Using Taq polymerase stop and FRET melting assays, we have demonstrated their ability to stabilize G-quadruplexes in the HIV-1 long-terminal repeat sequence. Moreover, these compounds were not binding to the general G-rich region, but rather to G-quadruplex-forming regions. Finally, docking and molecular dynamics calculations indicate that the structure of the helquat core greatly affects the binding mode to the individual G-quadruplexes. Our findings can provide useful information for the further rational design of inhibitors targeting G-quadruplexes in HIV-1.

• MeSH
• G-kvadruplexy * MeSH
• HIV-1 * genetika   MeSH
• koncové repetice MeSH
• promotorové oblasti (genetika) MeSH
• reverzní transkripce MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• Publikační typ
• tisková chyba MeSH

The oligoadenylate synthetase-ribonuclease L pathway is a major player in the interferon-induced antiviral defense mechanism of cells. Upon sensing viral dsRNA, 5'-phosphorylated 2',5'-oligoadenylates are synthesized, and subsequently activate latent RNase L. To determine the influence of 5'-phosphate end on the activation of human RNase L, four sets of 5'-phosphonate modified oligoadenylates were prepared on solid-phase. The ability of these 5'-modified oligoadenylates bearing shortened, isosteric and prolonged phosphonate linkages to activate RNase L was explored. We found that isosteric linkages and linkages prolonged by one atom were in general well tolerated by the enzyme with the EC50 values comparable to that of the natural activator. In contrast, linkages shortened by one atom or prolonged by two atoms exhibited decrease in the activity.

• MeSH
• adeninnukleotidy chemická syntéza   chemie   farmakologie   MeSH
• endoribonukleasy metabolismus   MeSH
• konformace nukleové kyseliny MeSH
• lidé MeSH
• oligoribonukleotidy chemická syntéza   chemie   farmakologie   MeSH
• organofosfonáty chemická syntéza   chemie   farmakologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

A series of 7-deazaadenine ribonucleosides bearing alkyl, alkenyl, alkynyl, aryl, or hetaryl groups at position 7 as well as their 5'-O-triphosphates and two types of monophosphate prodrugs (phosphoramidates and S-acylthioethanol esters) were prepared and tested for antiviral activity against selected RNA viruses (Dengue, Zika, tick-borne encephalitis, West Nile, and SARS-CoV-2). The modified triphosphates inhibited the viral RNA-dependent RNA polymerases at micromolar concentrations through the incorporation of the modified nucleotide and stopping a further extension of the RNA chain. 7-Deazaadenosine nucleosides bearing ethynyl or small hetaryl groups at position 7 showed (sub)micromolar antiviral activities but significant cytotoxicity, whereas the nucleosides bearing bulkier heterocycles were still active but less toxic. Unexpectedly, the monophosphate prodrugs were similarly or less active than the corresponding nucleosides in the in vitro antiviral assays, although the bis(S-acylthioethanol) prodrug 14h was transported to the Huh7 cells and efficiently released the nucleoside monophosphate.

• MeSH
• antivirové látky farmakologie   MeSH
• COVID-19 virologie   MeSH
• farmakoterapie COVID-19 MeSH
• fosfáty farmakologie   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• prekurzory léčiv farmakologie   MeSH
• purinové nukleosidy MeSH
• puriny farmakologie   MeSH
• ribonukleosidy farmakologie   MeSH
• RNA-dependentní RNA-polymerasa metabolismus   MeSH
• RNA-viry účinky léků   MeSH
• SARS-CoV-2 účinky léků   MeSH
• virus dengue účinky léků   MeSH
• virus západního Nilu účinky léků   MeSH
• virus zika účinky léků   MeSH
• viry klíšťové encefalitidy účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

G -kvadruplexy (G4) se za půl století studia staly z přírodní hříčky jednou z nejstudovanějších struktur nukleových kyselin. Lokalizace G4 do funkčních oblastí DNA a RNA poukazuje na množství buněčných procesů, které je možné regulovat formováním G4. Důkazy o jejich existenci in vivo, stejně jako možnost jejich stabilizace prostřednictvím nízkomolekulárních látek – ligandů G4, přináší nové terapeutické možnosti zejména v oblasti onkologie, kde narušení funkce telomer, replikace DNA, či exprese onkogenů vede k inhibici růstu nádoro-vých buněk.

Within the last 50 years, G -quadruplexes (G4) have become one of the most studied structures of nucleic acids. Localization of the G4 into the functional regions of the DNA and RNA indicates a number of cellular processes that can be regulated by G4 formation. Evi-dence of their existence in vivo as well as the possibility of their stabilization by low molecular weight G4 ligands brings new treatment opportunities, particularly in the field of oncology, where telomere disruption, inhibition of DNA replication, or oncogenic expression may affect tumor cell growth.

• MeSH
• antitumorózní látky MeSH
• DNA genetika   MeSH
• G-kvadruplexy * účinky léků   MeSH
• lidé MeSH
• ligandy MeSH
• nádory farmakoterapie   genetika   MeSH
• onkogeny účinky léků   MeSH
• regulace genové exprese u nádorů MeSH
• replikace DNA genetika   MeSH
• RNA metabolismus   MeSH
• rostliny MeSH
• telomerasa antagonisté a inhibitory   metabolismus   MeSH
• telomery mikrobiologie   MeSH
• vyvíjení léků MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH

We describe the expression and purification of an active recombinant Zika virus RNA-dependent RNA polymerase (RdRp). Next, we present the development and optimization of an in vitro assay to measure its activity. We then applied the assay to selected triphosphate analogs and discovered that 2'-C-methylated nucleosides exhibit strong inhibitory activity. Surprisingly, also carbocyclic derivatives with the carbohydrate locked in a North-like conformation as well as a ribonucleotide with a South conformation exhibited strong activity. Our results suggest that the traditional 2'-C-methylated nucleosides pursued in the race for anti-HCV treatment can be superseded by brand new scaffolds in the case of the Zika virus.

• MeSH
• adenosintrifosfát analogy a deriváty   chemie   MeSH
• antivirové látky farmakologie   MeSH
• inhibitory enzymů farmakologie   MeSH
• lidé MeSH
• molekulární konformace MeSH
• nukleosidy chemie   farmakologie   MeSH
• objevování léků MeSH
• RNA-dependentní RNA-polymerasa antagonisté a inhibitory   genetika   izolace a purifikace   MeSH
• virus zika účinky léků   enzymologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• Klíčová slova
• síť lékáren,
• MeSH
• lékárny * organizace a řízení   MeSH
• profesionální nezávislost MeSH
• Publikační typ
• rozhovory MeSH

The moss Physcomitrella patens is unique for the high frequency of homologous recombination, haploid state, and filamentous growth during early stages of the vegetative growth, which makes it an excellent model plant to study DNA damage responses. We used single cell gel electrophoresis (comet) assay to determine kinetics of response to Bleomycin induced DNA oxidative damage and single and double strand breaks in wild type and mutant lig4 Physcomitrella lines. Moreover, APT gene when inactivated by induced mutations was used as selectable marker to ascertain mutational background at nucleotide level by sequencing of the APT locus. We show that extensive repair of DSBs occurs also in the absence of the functional LIG4, whereas repair of SSBs is seriously compromised. From analysis of induced mutations we conclude that their accumulation rather than remaining lesions in DNA and blocking progression through cell cycle is incompatible with normal plant growth and development and leads to sensitive phenotype.

• MeSH
• analýza jednotlivých buněk MeSH
• bleomycin farmakologie   MeSH
• buněčný cyklus genetika   MeSH
• haploidie * MeSH
• homologní rekombinace genetika   MeSH
• mechy genetika   růst a vývoj   MeSH
• mutace MeSH
• mutageneze genetika   MeSH
• mutageny farmakologie   MeSH
• oprava DNA genetika   MeSH
• oxidační stres účinky léků   MeSH
• poškození DNA účinky léků   MeSH
• regulace genové exprese u rostlin MeSH
• rostlinné proteiny biosyntéza   genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH