0000000000178302

AUTHOR

Gunars Duburs

showing 18 related works from this author

ChemInform Abstract: Synthesis and Self-Assembly of Novel Fluorous Cationic Amphiphiles with a 3,4-Dihydro-2(1H)-pyridone Spacer.

2011

Abstract The synthesis of fluorous (highly fluorinated) 3,4-dihydro-2(1 H )-pyridone-5-carboxylate cationic amphiphiles have been described, where the dihydropyridone serves as a spacer and either a pyridinium bromide or a triphenylphosphonium bromide form the polar cationic head group. The in water self-assembled aggregates have been observed by atomic force microscopy (AFM) and dynamic light scattering (DLS).

chemistry.chemical_compoundPyridinium bromideDynamic light scatteringAtomic force microscopyChemistryBromidePolymer chemistryAmphiphileCationic polymerizationGeneral MedicineSelf-assemblyChemInform
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P5

2013

Background Pathogenic action of nitric oxide (NO) is responsible to a large extent for development of complications of the diabetes mellitus (DM). NO overproduction is largerly responsible for development of diabetic nephropathy. Thus search for compounds modifying NO production appears to be important for development of pharmacological remedies for treatment of DM complications. Dihydropiridines (DHP) appear to be prospective compounds from this point of view. The goal of the present work was to study alterations of NO production in streptozotocin model of DM in rats and ability of several DHPs and to normalize NO synthesis in kidneys of these animals. Methods Diabetes mellitus was induced…

Cancer Researchmedicine.medical_specialtyOxidase testbiologyPhysiologyClinical BiochemistryAllopurinolmedicine.diseaseStreptozotocinbiology.organism_classificationBiochemistryNitric oxideDiabetic nephropathychemistry.chemical_compoundEndocrinologychemistryEnosInternal medicineDiabetes mellitusmedicineXanthine oxidasemedicine.drugNitric Oxide
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Metal ions modify DNA-protecting and mutagen-scavenging capacities of the AV-153 1,4-dihydropyridine.

2019

Abstract 1,4-Dihydropyridines (1,4-DHP) possess important biochemical and pharmacological properties, including antioxidant and antimutagenic activities. AV-153-Na, an antimutagenic and DNA-repair enhancing compound was shown to interact with DNA by intercalation. Here we studied DNA binding of several AV-153 salts to evaluate the impact of AV-153 modifications on its DNA binding capacity, the ability to scavenge the peroxynitrite, to protect HeLa and B-cells cells against DNA damage. Affinity of the AV-153 salts to DNA measured by a fluorescence assay was dependent on the metal ion forming a salt in position 4 of the 1,4-DHP, and it decreased as follows: Mg > Na > Ca > Li > Rb > K. AV-153-…

DihydropyridinesAntioxidantDNA RepairDNA damageHealth Toxicology and Mutagenesismedicine.medical_treatmentMetal ions in aqueous solutionIntercalation (chemistry)[SDV.CAN]Life Sciences [q-bio]/CancerMutagen02 engineering and technologymedicine.disease_causeNiacinAntioxidantsHeLa03 medical and health scienceschemistry.chemical_compoundPeroxynitrous AcidGeneticsmedicineHumansDrug InteractionsDNA Breaks Single-StrandedComputingMilieux_MISCELLANEOUS030304 developmental biology0303 health sciencesB-Lymphocytesbiology021001 nanoscience & nanotechnologybiology.organism_classificationIntercalating AgentsRecombinant ProteinsOxidative StresschemistryMetalsBiophysicstat Gene Products Human Immunodeficiency VirusComet AssaySingle-Cell Analysis0210 nano-technologyDNAPeroxynitriteDNA DamageHeLa CellsMutation research. Genetic toxicology and environmental mutagenesis
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Comparative study of taurine and tauropyrone: GABA receptor binding, mitochondrial processes and behaviour.

2011

Abstract Objectives Taurine, a sulfur-containing amino acid, has high hydrophilicity and is poorly absorbed. Tauropyrone, a taurine-containing 1,4-dihydropyridine derivative, is suggested to have greater activity than taurine owing to improved physicochemical properties that facilitate delivery of the compound to target cells. The aim of this study was to determine whether the 1,4-dihydropyridine moiety in tauropyrone improves the pharmacological efficacy of taurine in vitro and in vivo. Methods The effects of taurine and tauropyrone, as well as of the 1,4-dihydropyridine moiety were compared in in-vitro experiments to determine the binding to GABA receptors and influence on mitochondrial p…

Malemedicine.medical_specialtyTaurineDihydropyridinesGABA receptor bindingTaurinePharmaceutical SciencePharmacologyMotor ActivityBicucullinechemistry.chemical_compoundMiceStructure-Activity RelationshipIn vivoSeizuresInternal medicinemedicineStructure–activity relationshipAnimalsRats WistarReceptorPharmacologychemistry.chemical_classificationMice Inbred ICRDiazepamBehavior AnimalEthanolChemistryGABAA receptorBicucullineReceptors GABA-AAmino acidMitochondriaRatsEndocrinologyMuscle TonusRotarod Performance TestEnergy MetabolismHydrophobic and Hydrophilic Interactionsmedicine.drugProtein BindingThe Journal of pharmacy and pharmacology
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1,4-Dihydropyridine derivatives without Ca2+-antagonist activity up-regulatePsma6mRNA expression in kidneys of intact and diabetic rats

2015

Impaired degradation of proteins by the ubiquitin-proteasome system (UPS) is observed in numerous pathologies including diabetes mellitus (DM) and its complications. Dysregulation of proteasomal degradation might be because of altered expression of genes and proteins involved in the UPS. The search for novel compounds able to normalize expression of the UPS appears to be a topical problem. A novel group of 1,4-dihydropyridine (1,4-DHP) derivatives lacking Ca2+-antagonists activities, but capable to produce antidiabetic, antioxidant and DNA repair enhancing effects, were tested for ability to modify Psma6 mRNA expression levels in rat kidneys and blood in healthy animals and in rats with str…

0301 basic medicinemedicine.medical_specialtyKidneyAntioxidantmedicine.medical_treatmentClinical BiochemistryCell BiologyGeneral MedicineBiologyStreptozotocinmedicine.diseaseBiochemistry03 medical and health sciences030104 developmental biologyReal-time polymerase chain reactionmedicine.anatomical_structureEndocrinologyDownregulation and upregulationInternal medicineDiabetes mellitusGene expressionmedicineGenemedicine.drugCell Biochemistry and Function
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Anti-Neurotoxic Effects of Tauropyrone, a Taurine Analogue

2006

Taurinechemistry.chemical_compoundTauropyroneChemistryPharmacologyFree Radical Formation
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3,4-trans-4-Aryl-3-(1-pyridinio)-1,2,3,4-tetrahydropyridine-6-thiolates—new group of potential cardiotonic drugs

2005

Abstract 3,4- trans -4-Aryl-3-(1-pyridinio)-1,2,3,4-tetrahydropyridine-6-thiolates 6 – 11 were prepared by a Michael reaction of N -acetonylpyridinium chloride with 3-aryl-2-cyanothioacrylamides or by a one-pot three-carbon condensation of N -acetonylpyridinium chloride, aromatic aldehyde and 2-cyanothioacetamide, and their cardiotonic properties were studied. 3,4- trans -5-cyano-2-hydroxy-2-methyl-4-(3-nitrophenyl)-3-(1-pyridinio)-1,2,3,4-tetrahydropyridine-6-thiolate 8 was considered as a lead compound in this series since it in vitro experiments (spontaneously beating rat atria) showed a cardiotonic activity similar to that of milrinone 2 , however compound 8 induced activity at lover co…

ChronotropicCardiotonic AgentsPyridinesStereochemistryGuinea PigsBlood PressureCardiac activityIn Vitro TechniquesCardiotonic AgentsAldehydeChlorideChemical synthesischemistry.chemical_compoundHeart RateGroup (periodic table)Drug DiscoverymedicineAnimalsSulfhydryl CompoundsRats WistarPharmacologychemistry.chemical_classificationCardiotonic drugsArylOrganic ChemistryGeneral MedicineRatschemistryMilrinoneLead compoundMilrinonemedicine.drugEuropean Journal of Medicinal Chemistry
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Synthesis and self-assembly of novel fluorous cationic amphiphiles with a 3,4-dihydro-2(1H)-pyridone spacer

2011

Abstract The synthesis of fluorous (highly fluorinated) 3,4-dihydro-2(1 H )-pyridone-5-carboxylate cationic amphiphiles have been described, where the dihydropyridone serves as a spacer and either a pyridinium bromide or a triphenylphosphonium bromide form the polar cationic head group. The in water self-assembled aggregates have been observed by atomic force microscopy (AFM) and dynamic light scattering (DLS).

Pyridinium bromideAtomic force microscopyOrganic ChemistryCationic polymerizationBiochemistryInorganic Chemistrychemistry.chemical_compoundchemistryDynamic light scatteringBromidePolymer chemistryAmphiphileEnvironmental ChemistryOrganic chemistrySelf-assemblyPhysical and Theoretical ChemistryJournal of Fluorine Chemistry
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DNA-binding studies of a series of novel water-soluble derivatives of 1,4-dihydropyridine

2018

Aim. to determine DNA interaction modes for a series of 1,4-dihydropyridines with different biological activities synthesized in the Latvian Institute of Or-ganic Synthesis. Methods. Affinity of the compounds to DNA was detected by UV/VIS spec-trometry and re-proofed by means of spectrofluorimetry, EBr extrusion assay, cyclic voltammetry and DNA melting. Radical scavenging was tested by electron paramagnetic resonance spectros-copy, peroxynitrite binding was monitored spectrophotometrically, protection of DNA against hydroxyl radical was determined by gel electrophoresis. Results. In a series of water-soluble monocyclic derivatives of 1,4-dihydropyridine with carboxylate groups in position-…

chemistry.chemical_compoundWater solubleSeries (mathematics)ChemistryBioorganic ChemistryDihydropyridinemedicineCombinatorial chemistryGeneral Biochemistry Genetics and Molecular BiologyDNAmedicine.drugBiopolymers and Cell
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Modifications of expression of genes and proteins involved in DNA repair and nitric oxide metabolism by carbatonides [disodium-2,6-dimethyl-1,4-dihyd…

2017

Abstract Studies on the pathogenesis of diabetes mellitus complications indicate that the compounds reducing free radicals and enhancing DNA repair could be prospective as possible remedies. Carbatonides, the disodium-2,6-dimethyl-1,4- dihydropyridine-3,5-bis(carbonyloxyacetate) derivatives, were tested for these properties. EPR spectroscopy showed that metcarbatone was an effective scavenger of hydroxyl radicals produced in the Fenton reaction, etcarbatone, and propcarbatone were less effective, styrylcarbatone was ineffective. UV/VIS spectroscopy revealed that styrylcarbatone manifested a hyperchromic effect when interacting with DNA, while all other carbatonides showeda hypochromic effec…

Male0301 basic medicineDihydropyridinesDNA RepairDNA damageDNA repairGene ExpressionPharmacologyNitric OxideToxicologyDiabetes Mellitus ExperimentalDiabetes Complications03 medical and health sciences0302 clinical medicineEnosDiabetes mellitusGene expressionmedicineAnimalsProspective StudiesbiologyChemistryPublic Health Environmental and Occupational HealthDihydropyridinemedicine.diseasebiology.organism_classificationStreptozotocinRatsComet assay030104 developmental biology030220 oncology & carcinogenesismedicine.drugArchives of Industrial Hygiene and Toxicology
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Spectroscopic and electrochemical study of interactions between DNA and different salts of 1,4-dihydropyridine AV-153

2020

1,4-dihydropyridines (1,4-DHP) possess important biochemical and pharmacological properties, including antimutagenic and DNA-binding activity. The latter activity was first described for water-soluble 1,4-DHP with carboxylic group in position 4, the sodium salt of the 1,4-DHP derivative AV-153 among others. Some data show the modification of physicochemical properties and biological activities of organic compounds by metal ions that form the salts. We demonstrated the different affinity to DNA and DNA-protecting capacity of AV-153 salts, depending on the salt-forming ion (Na, K, Li, Rb, Ca, Mg). This study aimed to use different approaches to collate data on the DNA-binding mode of AV-153-N…

Circular dichroismGuanine030303 biophysicsIntercalation (chemistry)Biophysicslcsh:MedicineCircular dichroismG-quadruplexBiochemistryMedicinal chemistryGeneral Biochemistry Genetics and Molecular BiologyNucleobase03 medical and health scienceschemistry.chemical_compoundCircular voltammetryMoleculeDenaturation (biochemistry)DNA bindingMolecular Biology14-dihydropyridines030304 developmental biologyAV-153 salts0303 health sciencesGeneral Neurosciencelcsh:RGeneral MedicineG-quadruplexeschemistryFourier-transformed infrared spectroscopySpectrofluorimetryGeneral Agricultural and Biological SciencesDNAPeerJ
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Search for Stroke-Protecting Agents in Endothelin-1-Induced Ischemic Stroke Model in Rats

2012

Background and Objective. Ischemic stroke may initiate a reperfusion injury leading to brain damage cascades where inflammatory mechanisms play a major role. Therefore, the necessity for the novel stroke-protecting agents whose the mechanism of action is focused on their anti-inflammatory potency is still on the agenda for drug designers. Our previous studies demonstrated that cerebrocrast (a 1,4-dihydropyridine derivative) and mildronate (a representative of the aza-butyrobetaine class) possessed considerable anti-inflammatory and neuroprotective properties in different in vitro and in vivo model systems. The present study investigated their stroke-protecting ability in an endothelin-1 (ET…

MaleDihydropyridinesDrug Evaluation PreclinicalInfarctionBrain damagePharmacologyNeuroprotectionIn vivomedicineAnimalsRats WistarStrokeEndothelin-1business.industryGeneral Medicinemedicine.diseaseRatsStrokeDisease Models AnimalNeuroprotective AgentsMechanism of actionendothelin-1; ischemic stroke; neurodegeneration; protection; cerebrocrast; mildronateDrug Therapy Combinationmedicine.symptombusinessReperfusion injuryEx vivoMethylhydrazinesMedicina; Volume 48; Issue 10; Pages: 77
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1,4 dihidropiridinski derivati povećavaju ekspresiju gena Psma3, Psmb5 i Psmc6 u glasničkoj RNA štakora

2021

The ubiquitin-proteasome system modifies different cellular and protein functions. Its dysregulation may lead to disrupted proteostasis associated with multiple pathologies and aging. Pharmacological regulation of proteasome functions is already an important part of the treatment of several diseases. 1,4-dihydropyridine (1,4-DHP) derivatives possess different pharmacological activities, including antiaging and neuroprotective. The aim of this study was to investigate the effects of several 1,4-DHP derivatives on mRNA expression levels of proteasomal genes Psma3, Psmb5, and Psmc6 in several organs of rats. Rats were treated with metcarbatone, etcarbatone, glutapyrone, styrylcarbatone, AV-153…

glutapironDihydropyridinesProteasome Endopeptidase Complexetcarbatoneporemećena proteasomska funkcijaimpaired proteasomal functionsproteasome subunitsToxicologyPSMA3metkarbatonKidneyNeuroprotectionPSMC6glutapyroneAV-153-NaAV-153-Ca; AV-153-Na; etcarbatone; gene expression; glutapyrone; impaired proteasomal functions; metcarbatone; pharmacological activities; proteasome subunits; styrylcarbatone; ubiquitin-proteasome systemAV-153-Ca; AV-153-Na; etkarbaton; glutapiron; metkarbaton; stirilkarbaton; poremećena proteasomska funkcija; proteasomske podjedinice; ubikvitin-proteasomski sustavGene expressionAnimalsstyrylcarbatoneRNA MessengerGeneChemistryPublic Health Environmental and Occupational HealthPSMB5Cell biologyproteasomske podjediniceRatsProteostasisProteasomeubikvitin-proteasomski sustavstirilkarbatongene expressionOriginal Articlepharmacological activitiesAV-153-Caubiquitin-proteasome systemmetcarbatoneetkarbatonArchives of Industrial Hygiene and Toxicology
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Distinct influence of atypical 1,4-dihydropyridine compounds in azidothymidine-induced neuro- and cardiotoxicity in mice ex vivo.

2008

This study demonstrates the effective protection by compounds of atypical 1,4-dihydropyridine (DHP) series cerebrocrast, glutapyrone and tauropyrone against neuro- and cardiotoxicity caused by the model compound azidothymidine, a well-known mitochondria-compromising anti-HIV drug. In previous in vitro experiments, we have demonstrated distinct effects of these DHP compounds to influence mitochondrial functioning. In the present in vivo experiments, DHP compounds were administered intraperitoneally in mice daily for 2 weeks, per se and in combinations with azidothymidine at doses: azidothymidine 50 mg/kg; cerebrocrast 0.1 mg/kg; glutapyrone 1 mg/kg; and tauropyrone 1 mg/kg. At the end of the…

MaleDihydropyridinesHeart DiseasesRatónAnti-HIV AgentsTaurineApoptosisBiologyPharmacologyToxicologyMiceGlutamatesIn vivomedicineAnimalsPharmacologyCerebral CortexInflammationCardiotoxicityMice Inbred ICRCaspase 3DihydropyridineTranscription Factor RelAGeneral MedicineBiochemistryGene Expression RegulationEnzyme inhibitorApoptosisToxicitybiology.proteinNeurotoxicity SyndromesZidovudineEx vivomedicine.drugBasicclinical pharmacologytoxicology
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DNA-binding studies of AV-153, an antimutagenic and DNA repair-stimulating derivative of 1,4-dihydropiridine.

2014

Abstract The ability to intercalate between DNA strands determines the cytotoxic activity of numerous anticancer drugs. Strikingly, intercalating activity was also reported for some compounds considered to be antimutagenic. The aim of this study was to determine the mode of interaction of DNA with the antimutagenic and DNA repair-stimulating dihydropyridine (DHP) AV-153. DNA and AV-153 interactions were studied by means of UV/VIS spectroscopy, fluorimetry and infrared spectroscopy. Compound AV-153 is a 1,4 dihydropyridine with ethoxycarbonyl groups in positions 3 and 5. Computer modeling of AV-153 and DNA interactions suggested an ability of the compound to dock between DNA strands at a sin…

DihydropyridinesBinding SitesDNA RepairMolecular StructureGuanineDNA repairStereochemistryAntimutagenic AgentsGeneral MedicineDNAToxicologyNiacinThymineRatschemistry.chemical_compoundPlasmidDNA IntercalationchemistryLiverSpectroscopy Fourier Transform InfraredAnimalsA-DNACytosineDNAChemico-biological interactions
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Anti-inflammatory effects of cerebrocrast in a model of rat paw edema and on mononuclear THP-1 cells.

2002

Cerebrocrast (IOS 1.1212; 4-[2-(difluoromethoxy)phenyl]-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylic acid di(2-propoxyethyl) diester) is a novel derivative of 1,4-dihydropyridine, which does not antagonize Ca(2+) influx in neuronal tissues. Since several classical dihydropyridines possess anti-inflammatory properties, we first studied the effects of cerebrocrast in a model of rat paw edema induced by carrageenan. Cerebrocrast had a preventative effect in this model of inflammation, with maximal activity (32-45% inhibition) in the 0.1-0.25 mg kg(-1) range. It was ineffective when added after the injection of carrageenan. Subsequent in vitro experiments showed that cerebrocrast in the mi…

Malemedicine.medical_specialtyDihydropyridinesmedicine.drug_classmedicine.medical_treatmentAnti-Inflammatory AgentsInflammationNeuroprotectionAnti-inflammatoryMonocyteschemistry.chemical_compoundInternal medicineForelimbmedicineTumor Cells CulturedAnimalsEdemaHumansTHP1 cell lineRats WistarPharmacologyDose-Response Relationship Drugbusiness.industryBiological activityCarrageenanRatsDisease Models AnimalEndocrinologyCytokinechemistryTumor necrosis factor alphamedicine.symptombusinessEuropean journal of pharmacology
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Gene delivery agents possessing antiradical activity: self-assembling cationic amphiphilic 1,4-dihydropyridine derivatives

2013

Seventeen 1,4-dihydropyridine (1,4-DHP) amphiphiles including differently substituted pyridinium, pyrazinium, N-methyl piperidinium or N-methyl morpholinium moieties as the cationic head-group of the molecule have been designed and synthesised. 1,4-DHP amphiphiles have been earlier proposed as a promising tool for plasmid DNA (pDNA) delivery in vitro. In this work the ability of the 1,4-DHP amphiphiles to self-assemble, to bind pDNA and to transfer it into the cells as well as the cytotoxicity of 1,4-DHP amphiphiles–pDNA complexes was studied. Furthermore, antiradical activity (ARA) of the 1,4-DHP derivatives was determined. We have revealed that all new 1,4-DHP amphiphiles possessed self-a…

endocrine systemAqueous solution010405 organic chemistryStereochemistrySubstituentCationic polymerizationGeneral ChemistryGene delivery010402 general chemistry01 natural sciencesCatalysis0104 chemical scienceschemistry.chemical_compoundchemistryAmphiphileMaterials ChemistryMoleculePyridiniumCytotoxicityNew Journal of Chemistry
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Distinct effects of atypical 1,4-dihydropyridines on 1-methyl-4-phenylpyridinium-induced toxicity.

2006

Our previous data obtained from in vivo experiments demonstrated high neuroprotective effects of three novel atypical neuronal non-calcium antagonistic 1,4-dihydropyridine (DHP) derivatives cerebrocrast, glutapyrone and tauropyrone. The present studies were carried out in vitro to clarify, at least in part, their mechanism of action in primary culture of cerebellar granule cells by use of 1-methyl-4-phenylpyridinium (MPP+) as a neurotoxic agent which causes dramatic oxidative stress. Cerebrocrast (highly lipophilic, with a classical two-ring structure) dose-dependently (0.01-10.0 microM, EC50 = 13 nM) reduced MPP+-induced cell death. At the same time, the calcium antagonist nimodipine (refe…

Membrane potentialNeurons1-Methyl-4-phenylpyridiniumDihydropyridinesCell DeathMolecular Structure1-Methyl-4-phenylpyridiniumClinical BiochemistryCell BiologyGeneral MedicineMitochondrionPharmacologyBiologymedicine.disease_causeBiochemistryNeuroprotectionMechanism of actionmedicinemedicine.symptomMode of actionReactive Oxygen SpeciesOxidative stressIntracellularCells CulturedCell biochemistry and function
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