A5020078517- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Supramolecular Chemistry and Complexes
- Crystallography and molecular interactions
- Molecular Sensors and Ion Detection
- HIV/AIDS drug development and treatment
- Synthesis and Characterization of Heterocyclic Compounds
- Parasite Biology and Host Interactions
- Carbohydrate Chemistry and Synthesis
- Biochemical and Molecular Research
- DNA and Nucleic Acid Chemistry
- Chemical Synthesis and Reactions
- Molecular spectroscopy and chirality
- Synthesis and Reactions of Organic Compounds
- Cyclopropane Reaction Mechanisms
- Parasites and Host Interactions
- Oxidative Organic Chemistry Reactions
- Education, Psychology, and Social Research
- Glycosylation and Glycoproteins Research
- Sulfur-Based Synthesis Techniques
- Aquaculture disease management and microbiota
- Organophosphorus compounds synthesis
- Synthesis and Biological Evaluation
- Catalytic Cross-Coupling Reactions
- Chemical Synthesis and Analysis
University of Chemistry and Technology, Prague
2016-2025
Charles University
2007-2021
University of Central Thailand
2015-2020
Institute of Spectroscopy
2015-2020
University of South Bohemia in České Budějovice
2017-2020
Masaryk University
2014-2019
Czech Academy of Sciences, Institute of Physics
2019
Central Research Laboratories (United Kingdom)
2015-2017
Ricardo Prague (Czechia)
1999-2012
Institute of Chemical Technology
1981-2012
The Suzuki-Miyaura reaction of protected 6-chloropurine and 2-amino-6-chloropurine bases nucleosides with substituted phenylboronic acids led to the corresponding 6-(substituted phenyl)purine derivatives 6-9. Their deprotection yielded a series 6-phenylpurine 10-13. Significant cytostatic activity (IC(50) 0.25-20 micromol/L) in CCRF-CEM, HeLa, L1210 cell lines was found for several 6-(4-X-substituted ribonucleosides 12 (X = H, F, Cl, OR), while 2-amino-6-phenylpurine 10 11, as well ribosides...
A new application of flavin derivatives in visible light photocatalysis was found. 1-Butyl-7,8-dimethoxy-3-methylalloxazine, when irradiated by light, shown to allow an efficient cyclobutane ring formation via intramolecular [2+2] cycloaddition both styrene dienes, considered as electron-rich substrates, and electron-poor bis(arylenones), presumably proceeding energy transfer mechanism.
A series of dialkyl esters purine and pyrimidine N-[2-(phosphonomethoxy)ethyl] derivatives substituted at position 2, 6, or 8 the base 4, 5 were prepared by alkylation appropriate heterocyclic with 2-chloroethoxymethylphosphonate diester in presence sodium hydride, cesium carbonate, 1,8-diazabicyclo[5,4, 0]undec-7-ene (DBU) dimethylformamide. Additional obtained transformations bases suitably modified intermediates bearing reactive functions moiety. The diesters converted to corresponding...
A series of fifteen 6-aryl-, 6-hetaryl- and 6-benzylpurine ribonucleosides has been prepared by Pd-catalyzed cross-coupling reactions 6-chloro-9-(2,3,5-tri- O -acetyl-β-D-ribofuranosyl)- purine with arylboronic acids, hetarylzinc halides, hetarylstannanes or benzylzinc halides followed deprotection. Structure-activity relationship study revealed that besides 6-(4-substituted phenyl)purine nucleosides, also some possess considerable cytostatic activity.
A new class of compounds, 9-[(2RS)-3-fluoro-2-phosphonylmethoxypropyl] [(RS)-FPMP] derivatives purines, is described that has selective activity against a broad spectrum retroviruses [including human immunodeficiency virus type 1 (HIV-1) and 2 (HIV-2)] but not other RNA or DNA viruses. This completely different from the parental 9-[(2S)-3-hydroxy-2-phosphonylmethoxypropyl] [(S)-HPMP] which are active range The racemic (RS)-FPMP adenine 2,6-diaminopurine, termed (RS)-FPMPA (RS)-FPMPDAP,...
Flavin-catalysed oxidative hydroxylation of substituted arylboronic acids by molecular oxygen with the assistance hydrazine or ascorbic acid resulted in phenols high yields. This mild organocatalytic protocol is compatible a variety functional groups and it alternatively usable for transformation alkylboronic to alcohols. Reaction takes place also water fulfils criteria green procedure.
Abstract Functional and phylogenetic diversity (FD PD respectively) of the resident community are expected to exert a key role in resistance colonization by surrounding species, their establishment success. However, few studies have explored this topic experimentally or evaluated interactive effects these measures. We implemented experiment disentangle FD sowing mixtures 6 drawn from pool 19 species naturally coexisting central European mesic meadows. The were designed cover four independent...
Summary Phenotypic plasticity, within and across generations (transgenerational plasticity), allows organisms their progeny to adapt the environment without modification of underlying DNA. Recent findings suggest that epigenetic modifications are important mediators such plasticity. However, empirical studies have, so far, mainly focused on plasticity in response abiotic factors, overlooking competition. We tested for within‐generation transgenerational phenotypic triggered by plant–plant...
Fe-catalyzed cross-coupling reactions of 9-substituted or protected 2,6-dichloropurines with 1 equiv methylmagnesium chloride gave regioselectively 2-chloro-6-methylpurines in good yields. The same 3 Pd-catalyzed trimethylaluminum afforded 2,6-dimethylpurines. underwent another coupling phenylboronic acid to give 6-methyl-2-phenylpurines. All were perfomed for Bn- and THP-protected purine bases as well acyl-protected ribosides 2-deoxyribosides. After deprotection, free nucleosides obtained.
Abstract A novel planar chiral flavinium salt, 3‐benzyl‐5‐ethyl‐10‐(8‐phenylnaphthalen‐1‐yl)isoalloxazinium perchlorate ( 2b ), which bears a phenyl cap that covers one side of the isoalloxazinium skeleton plane, has been prepared as potential catalyst for enantioselective H 2 O oxidation sulfides. The rate sulfides in presence racemic is comparable to reaction catalysed by 5‐ethyl‐3,10‐dimethylisoalloxazinium perchlorate, indicates bulky shielding substituent does not influence catalytic...
Reaction of phosphoroorganic synthons with 8-azaadenine, 8-aza-2,6-diaminopurine, and 8-azaguanine using cesium carbonate yielded regioisomeric 8-azapurine N7-, N8-, N9-(2-(phosphonomethoxy)alkyl) derivatives. This reaction followed by deprotection afforded isomeric 2-(phosphonomethoxy)ethyl (PME), (S)-(3-hydroxy-2-(phosphonomethoxy)propyl) [(S)-HPMP], (S)-(3-fluoro-2-(phosphonomethoxy)propyl) [(S)-FPMP], (S)-(2-(phosphonomethoxy)propyl) [(S)-PMP], (R)-(2-(phosphonomethoxy)propyl) [(R)-PMP]...
The preparation of N-(2-phosphonylmethoxyethyl) derivatives purine and pyrimidine bases, IV , as analogs the antiviral 9-(2-phosphonylmethoxyethyl)adenine (PMEA, I ), is described. synthesis consists in alkylation alkali metal salts heterocyclic bases or their N- O-substituted with diethyl 2- p -toluenesulfonyloxyethoxymethylphosphonate ( IIa 2-chloroethoxymethylphosphonate IIb ) 2-bromoethoxymethylphosphonate IIc ). obtained N-(2-diethoxyphosphonylmethoxyethyl) III were treated...
A modular and completely stereoselective approach for the construction of all-carbon tetrasubstituted alkenes is described. It based on three-fold, sequential metal-catalyzed, cross-coupling functionalization simple enolphosphate dibromide templates with carbon nucleophiles, affording as single isomers.
Abstract Experimental demethylation of plant DNA enables testing for epigenetic effects in a simple and straightforward way without the use expensive laborious sequencing. Plants are commonly demethylated during their germination with application agents such as 5‐azacytidine (5‐azaC). However, this approach can cause unwanted underdeveloped root systems high mortality treated plants, hindering full comparison untreated be applied only on reproducing by seeds. Here we test alternative method...
The observed positive diversity effect on ecosystem functioning has rarely been assessed in terms of intraspecific trait variability within populations. Intraspecific phenotypic could stem both from underlying genetic and plasticity response to environmental cues. latter might derive modifications a plant's epigenome potentially last multiple generations previous conditions. We experimentally disentangled the role parental environments population productivity, resistance against fluctuations...
A new, stepwise synthesis of calix[4]phyrins is described. It relies on the condensation a ketone with pyrrole to form dipyrromethane containing quaternary carbon center that subsequently condensed an aromatic aldehyde. This methodology, in contrast previous rational approach described by this group (involving formation trisubstituted via aldehyde pyrrole, followed acetone), allows for variety bulky, ketone-derived substituents be incorporated into meso-like positions. The resulting systems,...
Thiacalix[4]arene immobilized in the cone conformation undergoes a direct Gross formylation reaction (Cl2CH-O-CH3/SnCl4/CH2Cl2) to give upper-rim formylated thiacalixarene. Albeit using excess of agent and various temperatures, only one formyl group is introduced into meta position thiacalixarene skeleton. The surprising regioselectivity indicates dramatically different reactivity thiacalix[4]arene system when compared with classical calix[4]arene analogue, which yields exclusively para...
Abstract A series of 3‐substituted pyrazinium tetrafluoroborates was prepared as simple analogues flavinium salts which are efficient organocatalysts for oxidations with hydrogen peroxide. It shown that derivatives an electron‐withdrawing substituent catalyze mild sulfides to sulfoxides and Baeyer–Villiger in a similar way catalysts. The most reactive catalyst, 3‐cyanopyrazinium tetrafluoroborate, efficiently employed preparative sulfoxidations aromatic aliphatic well cyclobutanones....
The introduction of a 2-pyridylsulfoxide moiety into the upper rim calix[4]arenes enabled synthesis unprecedented derivatives with intramolecularly bridged meta positions two neighbouring aromatic subunits. Palladium-catalysed double C–H activation thus represents straightforward way to completely novel type calixarenes.