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
Nucleos(t)ide analogues entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are recommended as first-line monotherapies for chronic hepatitis B (CHB). Multiple HBV genotypes/subgenotypes have been described, but their impact on treatment response remains largely elusive. We investigated the effectiveness of ETV/TDF on HBV/D-subgenotypes, D1/D2/D3/D5, studied the structural/functional differences in subgenotype-specific reverse transcriptase (RT) domains of viral polymerase, and identified novel molecules with robust inhibitory activity on various D-subgenotypes. Transfection of Huh7 cells with full-length D1/D2/D3/D5 and in vitro TDF/ETV susceptibility assays demonstrated that D1/D2 had greater susceptibility to TDF/ETV while D3/D5 exhibited poorer response. Additionally, HBV load was substantially reduced in TDF-treated CHB patients carrying D1/D2 but minimally reduced in D3/D5-infected patients. Comparison of RT sequences of D-subgenotypes led to identification of unique subgenotype-specific residues, and molecular modeling/docking/simulation studies depicted differential bindings of TDF/ETV to the active site of their respective RTs. Replacement of signature residues in D3/D5 HBV clones with corresponding amino acids seen in D1/D2 improved their susceptibility to TDF/ETV. Using high throughput virtual screening, we identified N(9)-[3-fluoro-2-(phosphonomethoxy)propyl] (FPMP) derivatives of purine bases, including N6-substituted (S)-FPMP derivative of 2,6-diaminopurine (DAP) (OB-123-VK), as potential binders of RT of different D-subgenotypes. We synthesized (S)-FPMPG prodrugs (FK-381-FEE/FK-381-SEE/FK-382) and tested their effectiveness along with OB-123-VK. Both OB-123-VK and FK-381-FEE exerted similar antiviral activities against all D-subgenotypes, although FK-381-FEE was more potent. Our study highlighted the natural variation in therapeutic response of D1/D2/D3/D5 and emphasized the need for HBV subgenotype determination before treatment. Novel molecules described here could benefit future design/discovery of pan-D-subgenotypic inhibitors. IMPORTANCE Current treatment of chronic hepatitis B relies heavily on nucleotide/nucleoside analogs in particular, tenofovir disoproxil fumarate (TDF) and entecavir (ETV) to keep HBV replication under control and prevent end-stage liver diseases. However, it was unclear whether the therapeutic effects of TDF/ETV differ among patients infected with different HBV genotypes and subgenotypes. HBV genotype D is the most widespread of all HBV genotypes and multiple D-subgenotypes have been described. We here report that different subgenotypes of HBV genotype-D exhibit variable response toward TDF and ETV and this could be attributed to naturally occurring amino acid changes in the reverse transcriptase domain of the subgenotype-specific polymerase. Further, we identified novel molecules and also synthesized prodrugs that are equally effective on different D-subgenotypes and could facilitate management of HBV/D-infected patients irrespective of D-subgenotype.
- MeSH
- antivirové látky chemie farmakologie terapeutické užití MeSH
- chronická hepatitida B farmakoterapie virologie MeSH
- genotyp MeSH
- guanin analogy a deriváty chemie farmakologie terapeutické užití MeSH
- inhibitory reverzní transkriptasy chemie farmakologie terapeutické užití MeSH
- lidé MeSH
- mutace MeSH
- organofosfonáty chemie farmakologie MeSH
- prekurzory léčiv MeSH
- proteinové domény MeSH
- racionální návrh léčiv * MeSH
- reverzní transkriptasa chemie genetika MeSH
- tenofovir chemie farmakologie terapeutické užití MeSH
- virová léková rezistence účinky léků genetika MeSH
- virová nálož účinky léků MeSH
- virus hepatitidy B účinky léků enzymologie genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
This study describes the discovery of novel prodrugs bearing tyrosine derivatives instead of the phenol moiety present in FDA-approved tenofovir alafenamide fumarate (TAF). The synthesis was optimized to afford diastereomeric mixtures of novel prodrugs in one pot (yields up to 86%), and the epimers were resolved using a chiral HPLC column into fast-eluting and slow-eluting epimers. In human lymphocytes, the most efficient tyrosine-based prodrug reached a single-digit picomolar EC50 value against HIV-1 and nearly 300-fold higher selectivity index (SI) compared to TAF. In human hepatocytes, the most efficient prodrugs exhibited subnanomolar EC50 values for HBV and up to 26-fold higher SI compared to TAF. Metabolic studies demonstrated markedly higher cellular uptake of the prodrugs and substantially higher levels of released tenofovir inside the cells compared to TAF. These promising results provide a strong foundation for further evaluation of the reported prodrugs and their potential utility in the development of highly potent antivirals.
- MeSH
- amidy chemie MeSH
- antivirové látky chemie farmakologie MeSH
- fenol chemie MeSH
- hepatocyty virologie MeSH
- HIV-1 účinky léků MeSH
- kyseliny fosforečné chemie MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- objevování léků * MeSH
- prekurzory léčiv chemie farmakologie MeSH
- stereoizomerie MeSH
- tenofovir chemie farmakologie MeSH
- tyrosin chemie MeSH
- virus hepatitidy B účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Some pathogens, including parasites of the genus Trypanosoma causing Human and Animal African Trypanosomiases, cannot synthesize purines de novo and they entirely rely on the purine salvage pathway (PSP) for their nucleotide generation. Thus, their PSP enzymes are considered as promising drug targets, sparsely explored so far. Recently, a significant role of acyclic nucleoside phosphonates (ANPs) as inhibitors of key enzymes of PSP, namely of 6-oxopurine phosphoribosyltransferases (PRTs), has been discovered. Herein, we designed and synthesized two series of new ANPs branched at the C1' position as mimics of adenosine monophosphate. The novel ANPs efficaciously inhibited Trypanosoma brucei adenine PRT (TbrAPRT1) activity in vitro and it was shown that the configuration on the C1' chiral centre strongly influenced their activity: the (R)-enantiomers proved to be more potent compared to the (S)-enantiomers. Two ANPs, with Ki values of 0.39 μM and 0.57 μM, represent the most potent TbrAPRT1 inhibitors reported to date and they are an important tool to further study purine metabolism in various parasites.
- MeSH
- adeninfosforibosyltransferasa antagonisté a inhibitory metabolismus MeSH
- adenosinmonofosfát chemická syntéza chemie farmakologie MeSH
- antiprotozoální látky chemická syntéza chemie farmakologie MeSH
- inhibitory enzymů chemická syntéza chemie farmakologie MeSH
- molekulární struktura MeSH
- nukleosidy chemická syntéza chemie farmakologie MeSH
- parazitické testy citlivosti MeSH
- Trypanosoma brucei brucei účinky léků enzymologie MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Publikační typ
- časopisecké články MeSH
Acyclic nucleoside phosphonates (ANPs) represent a significant class of antiviral, anticancer, and antiprotozoal compounds. It is therefore highly desirable to have diverse synthetic routes leading towards these molecules. In the past, many structural modifications were explored, but surprisingly, the field of C1'-branched ANPs has been neglected with only a handful of articles reporting their synthesis. Herein we describe and compare five convenient approaches leading to key synthetic 6-chloropurine ANPs bearing the 9-phosphonomethoxyethyl (PME) moiety branched at the C1' position. These intermediates can be further vastly diversified into target C1'-branched ANPs bearing either natural or unnatural nucleobases. The importance of C1'-branched ANPs is emphasized by their analogy with C1'-substituted cyclic nucleotides (such as remdesivir, a broad-spectrum antiviral agent) and evaluation of their biological activity (e.g. antiviral, antineoplastic, and antiprotozoal) will be a tempting subject of further research.
- MeSH
- organofosfonáty * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
We report an extensive structure-activity relationship optimization of polysubstituted pyrimidines that led to the discovery of 5-butyl-4-(4-benzyloxyphenyl)-6-phenylpyrimidin-2-amine, and its difluorinated analogue. These compounds are sub-micromolar inhibitors of PGE2 production (IC50 as low as 12 nM). In order to identify the molecular target of anti-inflammatory pyrimidines, we performed extensive studies including enzymatic assays, homology modeling and docking. The difluorinated analogue simultaneously inhibits two key enzymes of the arachidonic acid cascade, namely mPGES-1 and COX-2, with mPGES-1 inhibition being the principal mechanism of action. Other pyrimidines studied are potent mPGES-1 inhibitors with no observed inhibition of COX-1/2 enzymes. Moreover, the two most potent compounds proved to be significantly effective in vivo in a model of acute inflammation, suppressing carrageenan-induced rat paw edema by 36 and 46 %. The promising results of this study warrant further preclinical evaluation of selected anti-inflammatory candidates.
- MeSH
- antiflogistika nesteroidní aplikace a dávkování chemie farmakologie MeSH
- aplikace orální MeSH
- buněčné linie MeSH
- dinoproston antagonisté a inhibitory biosyntéza MeSH
- edém chemicky indukované farmakoterapie MeSH
- karagenan MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- molekulární struktura MeSH
- myši MeSH
- objevování léků MeSH
- pyrimidiny aplikace a dávkování chemie farmakologie MeSH
- syntázy prostaglandinu E antagonisté a inhibitory metabolismus MeSH
- viabilita buněk účinky léků MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
As a part of a broader structure-activity relationship study of substituted 2-aminopyrimidines, the influence of the C-5 substitution on inhibition of prostaglandin E2 (PGE2) production was studied. Thirty compounds were prepared starting from the corresponding 2-amino-4,6-dichloropyrimidines using Suzuki cross-coupling. It was shown previously that 2-amino-4,6-dichloropyrimidines with smaller C-5 substituent (hydrogen and methyl) were devoid of significant activity, while 5-butyl derivatives exhibited prominent potency. In this study, on the other hand, both monoaryl- and bisarylpyrimidines were potent inhibitors of PGE2 production regardless the length of the C-5 substituent (hydrogen, methyl, n-butyl). Moreover, the shorter the C-5 substituent the higher potency to inhibit PGE2 production was observed. 2-Amino-4,6-diphenylpyrimidine was the best inhibitor of PGE2 production with IC50 = 3 nM and no cytotoxicity. The most potent inhibitors deserve further preclinical evaluation as potential anti-inflammatory agents.
- MeSH
- antiflogistika nesteroidní chemická syntéza chemie farmakologie MeSH
- biosyntetické dráhy účinky léků MeSH
- dinoproston antagonisté a inhibitory metabolismus MeSH
- kultivované buňky MeSH
- myši inbrední C57BL MeSH
- pyrimidiny chemická syntéza chemie farmakologie MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
As a part of our extensive structure-activity relationship study of anti-inflammatory heterocycles, a novel series of 67 polysubstituted 2-aminopyrimidines was prepared bearing one (at the C-4 position of the pyrimidine ring) or two (in the C-4 and C-6 positions) (hetero)aryl substituents attached directly through the C-C bond. The key synthetic steps involved either Suzuki-Miyaura or Stille cross-coupling reactions carried out on easily available 4,6-dichloropyrimidines. All prepared compounds, except one, were able to inhibit immune-activated production of nitric oxide (NO) significantly. Moreover, several compounds were found to be low micromolar dual inhibitors of NO and prostaglandin E2 (PGE2) production. Although the exact mode of action of the prepared compounds remains to be elucidated, non-toxic dual inhibitors of NO and PGE2 production may have great therapeutic benefit in treatment of various inflammation diseases and deserve further preclinical evaluation.
