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1.
Cancer Cell Int ; 24(1): 251, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39020347

RESUMO

Hypoxia represents one of the key factors that stimulates the growth of leukemic cells in their niche. Leukemic cells in hypoxic conditions are forced to reprogram their original transcriptome, miRNome, and metabolome. How the coupling of microRNAs (miRNAs)/mRNAs helps to maintain or progress the leukemic status is still not fully described. MiRNAs regulate practically all biological processes within cells and play a crucial role in the development/progression of leukemia. In the present study, we aimed to uncover the impact of hsa-miR-155-5p (miR-155, MIR155HG) on the metabolism, proliferation, and mRNA/miRNA network of human chronic lymphocytic leukemia cells (CLL) in hypoxic conditions. As a model of CLL, we used the human MEC-1 cell line where we deleted mature miR-155 with CRISPR/Cas9. We determined that miR-155 deficiency in leukemic MEC-1 cells results in lower proliferation even in hypoxic conditions in comparison to MEC-1 control cells. Additionally, in MEC-1 miR-155 deficient cells we observed decreased number of populations of cells in S phase. The miR-155 deficiency under hypoxic conditions was accompanied by an increased apoptosis. We detected a stimulatory effect of miR-155 deficiency and hypoxia at the level of gene expression, seen in significant overexpression of EGLN1, GLUT1, GLUT3 in MEC-1 miR-155 deficient cells. MiR-155 deficiency and hypoxia resulted in increase of glucose and lactate uptake. Pyruvate, ETC and ATP were reduced. To conclude, miR-155 deficiency and hypoxia affects glucose and lactate metabolism by stimulating the expression of glucose transporters as GLUT1, GLUT3, and EGLN1 [Hypoxia-inducible factor prolyl hydroxylase 2 (HIF-PH2)] genes in the MEC-1 cells.

2.
Folia Biol (Praha) ; 69(4): 127-132, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38410970

RESUMO

Propidium iodide (PI) and YO-PRO-1 (YPI) dyes are routinely used to determine sperm viability in many livestock species. It is commonly accepted that these dyes penetrate only sperm cells with damaged plasma membranes. Recently, however, the mechanism of dye uptake unrelated to damaged plasma membranes, but instead related to pannexin channels in dog and stallion sperm cells was demonstrated. This pilot study aimed to evaluate the role of pannexins in the uptake of PI and YPI dyes on Wallachian frozen-thawed ram spermatozoa by flow cytometry using probenecid, a specific inhibitor of pannexin channels. Additionally, the expression of pannexins in Wallachian sperm was evaluated directly (by qRT-PCR). The results demonstrate the active role of pannexin channels in the uptake of PI and YPI dyes on frozen-thawed Wallachian ram sperm. In conclusion, when using the PI or YPI exclusion assay to determine Wallachian frozen-thawed ram sperm viability, the danger of overestimating the number of spermatozoa with the damaged plasma membrane must be considered. The observed breed-specific, and more importantly, individual differences in gene expression as well as in dye uptake indicate the need for further studies.


Assuntos
Iodetos , Compostos de Quinolínio , Preservação do Sêmen , Masculino , Animais , Cavalos , Cães , Propídio , Projetos Piloto , Sêmen , Criopreservação/métodos , Criopreservação/veterinária , Preservação do Sêmen/veterinária , Preservação do Sêmen/métodos , Espermatozoides , Corantes , Benzoxazóis
4.
Sci Data ; 9(1): 499, 2022 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-35974021

RESUMO

How does psychology vary across human societies? The fundamental social motives framework adopts an evolutionary approach to capture the broad range of human social goals within a taxonomy of ancestrally recurring threats and opportunities. These motives-self-protection, disease avoidance, affiliation, status, mate acquisition, mate retention, and kin care-are high in fitness relevance and everyday salience, yet understudied cross-culturally. Here, we gathered data on these motives in 42 countries (N = 15,915) in two cross-sectional waves, including 19 countries (N = 10,907) for which data were gathered in both waves. Wave 1 was collected from mid-2016 through late 2019 (32 countries, N = 8,998; 3,302 male, 5,585 female; Mage = 24.43, SD = 7.91). Wave 2 was collected from April through November 2020, during the COVID-19 pandemic (29 countries, N = 6,917; 2,249 male, 4,218 female; Mage = 28.59, SD = 11.31). These data can be used to assess differences and similarities in people's fundamental social motives both across and within cultures, at different time points, and in relation to other commonly studied cultural indicators and outcomes.

5.
J Fungi (Basel) ; 7(3)2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33802751

RESUMO

Ascospores of Talaromyces.macrosporus belong to the most stress resistant eukaryotic cells and show a constitutive dormancy, i.e., no germination occurs in the presence of rich growth medium. Only an extreme trigger as very high temperature or pressure is able to evoke synchronized germination. In this study, several changes within the thick cell wall of these cells are observed after a heat treatment: (i.) a change in its structure as shown with EPR and X-ray diffraction; (ii.) a release of an abundant protein into the supernatant, which is proportional to the extent of heat activation; (iii.) a change in the permeability of the cell wall as judged by fluorescence studies in which staining of the interior of the cell wall correlates with germination of individual ascospores. The gene encoding the protein, dubbed ICARUS, was studied in detail and was expressed under growth conditions that showed intense ascomata (fruit body) and ascospore formation. It encodes a small 7-14 kD protein. Blast search exhibits that different Talaromyces species show a similar sequence, indicating that the protein also occurs in other species of the genus. Deletion strains show delayed ascomata formation, release of pigments into the growth medium, higher permeability of the cell wall and a markedly shorter heat activation needed for activation. Further, wild type ascospores are more heat-resistant. All these observations suggest that the protein plays a role in dormancy and is related to the structure and permeability of the ascospore cell wall. However, more research on this topic is needed to study constitutive dormancy in other fungal species that form stress-resistant ascospores.

6.
Plants (Basel) ; 9(6)2020 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-32545748

RESUMO

The article explores how location affected the dynamics of accumulation of ascorbic acid (AC) and oxidized forms of AC-dehydroascorbic acid (DAA) and diketogulonic acid (DKGA) in beach pea during ontogenetic development. Our analysis focuses on research of the ecological and geochemical conditions growing of the plant on the Curonian Spit. The level of hydrogen peroxide and the activity of enzymes that break it down were analyzed. Antioxidant activity and the total concentration of phenolics were evaluated in the leaves of beach pea on the leeward and windward sides of the foredune. It was established that the level of AC, DAA, and DKGA was higher in the plants growing on the windward side of the foredune. A higher concentration of peroxy compounds, which stimulate the biosynthesis of antioxidant enzymes (catalase, ascorbate peroxidase), polyphenols, and other low molecular antioxidants (AOA) was observed in the leaves of these plants. The plants on the windward side enter phenological stages one or two weeks later than their counterparts on the leeward side of the foredune do. There was a generally negative correlation between the temperature of the soil and the accumulation of ascorbate system acids in the leaves of the studied plants (r = -0.46/(-0.68), p < 0.05). The accumulation of low molecular antioxidants and enzymes in beach pea suggests their adaptation to the adverse conditions of the windward side of the foredune.

7.
Biotechnol Adv ; 37(1): 51-67, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30453013

RESUMO

Under natural conditions yeast cells as well as other microorganisms are regularly subjected to the influence of severe drought, which leads to their serious dehydration. The dry seasons are then changed by rains and there is a restoration of normal water potential inside the cells. To survive such seasonal changes a lot of vegetative microbial cells, which belong to various genera and species, may be able to enter into a state of anhydrobiosis, in which their metabolism is temporarily and reversibly suspended or delayed. This evolutionarily developed adaptation to extreme conditions of the environment is widely used for practical goals - for conservation of microorganisms in collections, for maintenance and long storage of different important strain-producers and for other various biotechnological purposes. This current review presents the most important data obtained mainly in the studies of the structural and functional changes in yeast cells during dehydration. It describes the changes of the main organelles of eukaryotic cells and their role in cell survival in a dry state. The review provides information regarding the role of water in the structure and functions of biological macromolecules and membranes. Some important intracellular protective reactions of eukaryotic organisms, which were revealed in these studies and may have more general importance, are also discussed. The results of the studies of yeast anhydrobiosis summarized in the review show the possibilities of improving the conservation and long-term storage of various microorganisms and of increasing the quality of industrially produced dry microbial preparations.


Assuntos
Biotecnologia , Desidratação/metabolismo , Saccharomyces cerevisiae/metabolismo , Água/metabolismo , Sobrevivência Celular/genética , Microambiente Celular/genética , Saccharomyces cerevisiae/genética
8.
Fungal Genet Biol ; 98: 61-70, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28011318

RESUMO

Conidia of Aspergillus niger are produced on conidiophores. Here, maturation of conidia on these asexual reproductive structures was studied. Pigmented conidia that had developed on conidiophores for 2, 5, and 8days were similarly resistant to heat and were metabolically active as shown by CO2 release and conversion of the metabolic probe Tempone. A total number of 645-2421 genes showed a ⩾2-fold change in expression when 2-day-old conidia were compared to 5- and 8-day-old spores. Melanin was extracted more easily from the cell wall of 2-day-old conidia when compared to the older spores. In addition, mannitol content and germination rate of the 2-day-old conidia were higher. Dispersal efficiency by water was lower in the case of the 8-day-old conidia but no differences were observed in dispersal by wind and a hydrophobic moving object. These data and the fact that only a minor fraction of the conidia on a conidiophore were dispersed in the assays imply that a single colony of A. niger releases a heterogeneous population of conidia. This heterogeneity would provide a selective advantage in environments with rapidly changing conditions such as availability of water.


Assuntos
Aspergillus niger/genética , Proteínas Fúngicas/genética , Heterogeneidade Genética , Esporos Fúngicos/genética , Aspergillus niger/crescimento & desenvolvimento , Parede Celular/metabolismo , Temperatura Alta , Reprodução Assexuada/genética , Esporos Fúngicos/crescimento & desenvolvimento
9.
Environ Microbiol ; 17(2): 383-94, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25040022

RESUMO

Fungal propagules survive stresses better than vegetative cells. Neosartorya fischeri, an Aspergillus teleomorph, forms ascospores that survive high temperatures or drying followed by heat. Not much is known about maturation and development of extreme stress resistance in fungal cells. This study provides a novel two-step model for the acquisition of extreme stress resistance and entry into dormancy. Ascospores of 11- and 15-day-old cultures exhibited heat resistance, physiological activity, accumulation of compatible solutes and a steep increase in cytoplasmic viscosity. Electron spin resonance spectroscopy indicated that this stage is associated with the removal of bulk water and an increase of chemical stability. Older ascospores from 15- to 50-day-old cultures showed no changes in compatible solute content and cytoplasmic viscosity, but did exhibit a further increase of heat resistance and redox stability with age. This stage was also characterized by changes in the composition of the mixture of compatible solutes. Mannitol levels decreased and the relative quantities of trehalose and trehalose-based oligosaccharides increased. Dormant ascospores of N. fischeri survive in low-water habitats. After activation of the germination process, the stress resistance decreases, compatible solutes are degraded and the cellular viscosity drops. After 5 h, the hydrated cells enter the vegetative stage and redox stability has decreased notably.


Assuntos
Manitol/metabolismo , Neosartorya/crescimento & desenvolvimento , Neosartorya/metabolismo , Esporos Fúngicos/metabolismo , Trealose/metabolismo , Citoplasma/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica , Temperatura Alta , Oxirredução , Viscosidade , Água/metabolismo
10.
Environ Microbiol ; 17(2): 395-411, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25040129

RESUMO

Ascospores of Neosartorya, Byssochlamys and Talaromyces can be regarded as the most stress-resistant eukaryotic cells. They can survive exposure at temperatures as high as 85°C for 100 min or more. Neosartorya fischeri ascospores are more viscous and more resistant to the combined stress of heat and desiccation than the ascospores of Talaromyces macrosporus which contain predominantly trehalose. These ascospores contain trehalose-based oligosaccharides (TOS) that are novel compatible solutes, which are accumulated to high levels. These compounds are also found in other members of the genus Neosartorya and in some other genera within the order Eurotiales that also include Byssochlamys and Talaromyces. The presence of oligosaccharides was observed in species that had a relatively high growth temperature. TOS glasses have a higher glass transition temperature (Tg ) than trehalose, and they form a stable glass with crystallizing molecules, such as mannitol. Our data indicate that TOS are important for prolonged stabilization of cells against stress. The possible unique role of these solutes in protection against dry heat conditions is discussed.


Assuntos
Neosartorya/metabolismo , Esporos Fúngicos/metabolismo , Estresse Fisiológico/fisiologia , Talaromyces/metabolismo , Trealose/metabolismo , Desidratação , Microbiologia de Alimentos , Temperatura Alta , Prevalência , Esporos Fúngicos/crescimento & desenvolvimento , Temperatura , Viscosidade
11.
Front Microbiol ; 5: 150, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24772110

RESUMO

We were able to demonstrate that hydroxyectoine, in contrast to ectoine, is a good glass-forming compound. Fourier transform infrared and spin label electron spin resonance studies of dry ectoine and hydroxyectoine have shown that the superior glass-forming properties of hydroxyectoine result from stronger intermolecular H-bonds with the OH group of hydroxyectoine. Spin probe experiments have also shown that better molecular immobilization in dry hydroxyectoine provides better redox stability of the molecules embedded in this dry matrix. With a glass transition temperature of 87°C (vs. 47°C for ectoine) hydroxyectoine displays remarkable desiccation protection properties, on a par with sucrose and trehalose. This explains its accumulation in response to increased salinity and elevated temperature by halophiles such as Halomonas elongata and its successful application in ``anhydrobiotic engineering'' of both enzymes and whole cells.

12.
Bioorg Med Chem ; 21(15): 4614-27, 2013 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-23787290

RESUMO

Substituted diphenyl sulfones (10a-n) were synthesised, and the structures were confirmed by NMR, LC-MS and X-ray crystallography. Their antagonistic activities towards 5-HT6 receptor were assessed in a cell-based functional assay. Diphenyl sulfone 10a, in spite of being the smallest and simplest known sulfonyl-containing 5-HT6R antagonist, showed a strong potency (Ki=1.6 µM). Its derivative with a methylamine substituent, 10g (N-methyl-2-(phenylsulfonyl)aniline), was ∼66-times as active as diphenyl sulfone (Ki=24.3 nM). Addition of a piperazinyl moiety in the para-position relative to the sulfonyl group in compound 10m (N-methyl-2-(phenylsulfonyl)-5-piperazin-1-ylaniline) led to a further 150-fold increase in potency (Ki=0.16 nM) to block the serotonin-induced response of HEK-293 cells that were stably transfected with the human recombinant 5-HT6 receptor.


Assuntos
Receptores de Serotonina/química , Antagonistas da Serotonina/química , Antagonistas da Serotonina/farmacologia , Sulfonas/química , Sulfonas/farmacologia , Sequência de Aminoácidos , Células HEK293 , Humanos , Cinética , Ligantes , Dados de Sequência Molecular , Receptores de Serotonina/metabolismo , Antagonistas da Serotonina/síntese química , Relação Estrutura-Atividade , Sulfonas/síntese química , Transfecção
13.
Bioorg Med Chem Lett ; 22(13): 4273-80, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22664127

RESUMO

Synthesis and biological evaluation of a new series of structurally unrestricted and intramolecular hydrogen bond restricted derivatives of 3-(phenylsulfonyl)pyrazolo[1,5-a]pyrido[3,4-e]pyrimidines (angular tricyclics) and 3-(phenylsulfonyl)pyrazolo[1,5-a]pyrido[4,3-d]pyrimidines (linear tricyclics) are described. Structurally restricted derivatives are highly potent and selective blockers of 5-HT(6) receptors with little difference between angular or linear shape of the tricyclic core, the angular species being only slightly more potent. The angular representative of 3-(phenylsulfonyl)pyrazolo[1,5-a]pyrido[3,4-e]pyrimidines, 5, can be considered as more favorable candidate for further development as it shows only weak 5-HT(2B) blocking activity (IC(50)=6.16 µM as compared with IC(50)=1.8 nM for 5-HT(6) receptors) and very low hERG potassium channel blocking potency (IC(50)=54.2 µM). The linear analog, 11, is less favorable as while showing no binding to the 5-HT(2B) receptor at concentrations of up to 10 µM, it exhibits quite a high potency to block the hERG channel (IC(50)=0.5 µM).


Assuntos
Pirazóis/química , Pirimidinas/química , Receptores de Serotonina/química , Cristalografia por Raios X , Canal de Potássio ERG1 , Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , Canais de Potássio Éter-A-Go-Go/metabolismo , Ligação de Hidrogênio , Isomerismo , Conformação Molecular , Ligação Proteica , Pirimidinas/síntese química , Pirimidinas/metabolismo , Receptores de Serotonina/metabolismo , Antagonistas da Serotonina/química , Relação Estrutura-Atividade
14.
J Phys Chem A ; 116(1): 443-51, 2012 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-22032180

RESUMO

The 4-hydroxy-5,5-dimethyl-2-trifluoromethylpyrroline-1-oxide (FDMPO) spin trap is very attractive for spin trapping studies due to its high stability and high reaction rates with various free radicals. However, the identification of FDMPO radical adducts is a challenging task since they have very comparable Electron Spin Resonance (ESR) spectra. Here we propose a new method for the analysis and interpretation of the ESR spectra of FDMPO radical adducts. Thus, overlapping ESR spectra were analyzed using computer simulations. As a result, the N- and F-hyperfine splitting constants were obtained. Furthermore, an artificial neural network (ANN) was adopted to identify radical adducts formed during various processes (e.g., Fenton reaction, cleavage of peracetic acid over MnO(2), etc.). The ANN was effective on both "known" FDMPO radical adducts measured in slightly different solvents and not a priori "known" FDMPO radical adducts. Finally, the N- and F-hyperfine splitting constants of ·OH, ·CH(3), ·CH(2)OH, and CH(3)(C═O)O(·) radical adducts of FDMPO were calculated using density functional theory (DFT) at the B3LYP/6-31G(d,p)//B3LYP/6-31G++//B3LYP/EPR-II level of theory to confirm the experimental data.


Assuntos
Óxidos N-Cíclicos/química , Radicais Livres/análise , Redes Neurais de Computação , Pirróis/química , Simulação por Computador , Espectroscopia de Ressonância de Spin Eletrônica , Modelos Moleculares , Teoria Quântica , Marcadores de Spin , Detecção de Spin , Termodinâmica
15.
J Med Chem ; 54(23): 8161-73, 2011 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-22029285

RESUMO

Syntheses, biological evaluation as 5-HT(6) receptor (5-HT(6)R) antagonists, and structure-activity relationships for a series of novel 5,7-disubstituted (3-arylsulfonyl-pyrazolo[1,5-a]pyrimidins are disclosed. The molecule conformational flexibility in the series is restricted by formation of the intramolecular hydrogen bond between 3-sulfo and 2-methylamino groups, which renders high potency and high selectivity to block serotonin-induced responses in HEK-293 cells stably expressing human 5-HT(6)R. In this work, we tested the hypothesis if addition of a positively ionizable group (PI) to the pyrimidine ring of the scaffold members in positions 5, 6, or 7 could further increase their 5HT(6)R blocking potency. We show that the presence of the PI group with small substituents does not substantially affect either potency or selectivity of the ligands while causing substantial changes in their cLogP values. This provides a possibility for designing of the 5HT(6)R ligands with modified ADME characteristics without grossly affecting efficiency of their interaction with the receptor. In respect to the structure-activity relationship (SAR), among other physiochemical parameters, only the molecule size and shape (described by gyration radii) showed a clear tendency for more compact molecules to be more potent antagonists of this receptor.


Assuntos
Metilaminas/síntese química , Pirazóis/síntese química , Pirimidinas/síntese química , Receptores de Serotonina/metabolismo , Antagonistas da Serotonina/síntese química , Sulfonas/síntese química , Células HEK293 , Humanos , Metilaminas/química , Metilaminas/farmacologia , Modelos Moleculares , Pirazóis/química , Pirazóis/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Antagonistas da Serotonina/química , Antagonistas da Serotonina/farmacologia , Relação Estrutura-Atividade , Sulfonas/química , Sulfonas/farmacologia
16.
Bioorg Med Chem ; 19(4): 1482-91, 2011 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-21277782

RESUMO

Syntheses of a series of novel 3-sulfonyl-pyrazolo[1,5-a]pyrimidines and their 5-HT(6) receptor antagonistic structure-activity relationship are disclosed. The nature and position of substituents, which affect their receptor antagonistic activity, are analyzed. Among all synthesized derivatives, {3-(3-chlorophenylsulfonyl)-5,7-dimethyl-pyrazolo[1,5-a]pyrimidin-2-yl}-methyl-amine 33 (K(i)=190 pM), (3-phenylsulfonyl-7-methyl-pyrazolo[1,5-a]pyrimidin-2-yl)-methyl-amine 44 (K(i)=240 pM), (3-phenylsulfonyl-5-metoxymethyl-7-methyl-pyrazolo[1,5-a]pyrimidin-2-yl)-methyl-amine 50 (K(i)=270 pM), and (3-phenylsulfonyl-5-methyl-7-metoxymethyl-pyrazolo[1,5-a]pyrimidin-2-yl)-methyl-amine 52 (K(i)=280 pM) are the most potent antagonists of the 5-HT(6) receptors.


Assuntos
Compostos Heterocíclicos com 3 Anéis/síntese química , Compostos Heterocíclicos com 3 Anéis/farmacologia , Pirimidinas/síntese química , Pirimidinas/farmacologia , Receptores de Serotonina/metabolismo , Antagonistas da Serotonina/síntese química , Antagonistas da Serotonina/farmacologia , Linhagem Celular , Humanos , Modelos Moleculares , Estrutura Molecular , Pirazóis/química , Relação Estrutura-Atividade , Compostos de Enxofre/química
17.
Eur J Med Chem ; 46(4): 1189-97, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21333408

RESUMO

Syntheses, biological evaluation, and structure-activity relationships for a series of novel 2-substituted 3-benzenesulfonyl-5,6-dimethyl-pyrazolo[1,5-a]pyrimidines are disclosed. In spite of a wide, four orders of magnitude, SAR range (K(i) varied from 260 pM to 2.96 µM), no significant correlation of 5-HT(6)R antagonistic potency was observed with major physiochemical characteristics, such as molecular weight, surface polar area, cLogP, or number of rotatable bonds. Statistically significant trend was only observed for size of substitute group, which was not enough to explain the deep SAR trend. Besides with the substitute group size, another factor that presumably plays a role in defining the compound potencies is a relative position of the heterocycle and sulfophenyl moieties. Among all synthesized derivatives, (3-benzenesulfonyl-5,7-dimethyl-pyrazolo[1,5-a]pyrimidin-2-yl)-methyl-amine 18 is the most potent (K(i) = 260 pM) and extremely selective, 5000 to >50,000-fold relative to 55 therapeutic targets, antagonist of the 5-HT(6) receptor.


Assuntos
Desenho de Fármacos , Pirazóis/química , Pirazóis/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Receptores de Serotonina/metabolismo , Antagonistas da Serotonina/química , Antagonistas da Serotonina/farmacologia , Sulfonas/química , Sulfonas/farmacologia , Células HEK293 , Humanos , Modelos Moleculares , Conformação Molecular , Pirazóis/síntese química , Pirimidinas/síntese química , Receptores de Serotonina/química , Antagonistas da Serotonina/síntese química , Especificidade por Substrato , Sulfonas/síntese química
18.
Environ Sci Technol ; 44(17): 6815-21, 2010 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-20669941

RESUMO

The homolysis of peracetic acid (PAA) as a relevant source of free radicals (e.g., *OH) was studied in detail. Radicals formed as a result of chain radical reactions were detected with electron spin resonance and nuclear magnetic resonance spin trapping techniques and subsequently identified by means of the simulation-based fitting approach. The reaction mechanism, where a hydroxyl radical was a primary product of O-O bond rupture of PAA, was established with a complete assessment of relevant reaction thermochemistry. Total energy analysis of the reaction pathway was performed by electronic structure calculations (ab initio and semiempirical methods) at different levels and basis sets [e.g., HF/6-311G(d), B3LYP/6-31G(d)]. Furthermore, the heterogeneous MnO2/PAA system was tested for the elimination of a model aromatic compound, phenol from aqueous solution. An artificial neural network (ANN) was designed to associate the removal efficiency of phenol with relevant process parameters such as concentrations of both the catalyst and PAA and the reaction time. Results were used to train and test ANN to identify an optimized network structure, which represented the correlations between the operational parameters and removal efficiency of phenol.


Assuntos
Radicais Livres/química , Modelos Químicos , Ácido Peracético/química , Fenol/química , Teoria Quântica , Análise Espectral/métodos , Simulação por Computador , Óxidos N-Cíclicos/química , Espectroscopia de Ressonância de Spin Eletrônica , Compostos de Manganês/química , Redes Neurais de Computação , Organofosfonatos/química , Oxirredução , Óxidos/química , Detecção de Spin , Termodinâmica
19.
Bioorg Med Chem ; 18(14): 5282-90, 2010 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-20541425

RESUMO

A number of 3-(phenylsulfonyl)thieno[2,3-e][1,2,3]triazolo[1,5-a]pyrimidines were prepared and their 5-HT6 receptor binding affinity and ability to inhibit the functional cellular responses to serotonin were evaluated. 3-[(3-chlorophenyl)sulfonyl]-N-(tetrahydrofuran-2-ylmethyl)thieno[2,3-e][1,2,3]triazolo[1,5-a]pyrimidin-5-amine 2{5,26} appeared to be the most active in a functional assay (IC50=29.0 nM) and 3-(phenylsulfonyl)-N-(2-thienylmethyl) thieno[2,3-e][1,2,3]triazolo[1,5-a]pyrimidin-5-amine 2{1,28} demonstrated the greatest affinity in a 5-HT6 receptor radioligand binding assay (Ki=1.7 nM). A screening of 5-HT2A and 5-HT2B receptor affinity revealed that 3-(phenylsulfonyl)thieno[2,3-e][1,2,3]triazolo[1,5-a]pyrimidines are highly selective 5-HT6 receptor ligands.


Assuntos
Pirimidinas/química , Pirimidinas/farmacologia , Receptores de Serotonina/metabolismo , Agonistas do Receptor de Serotonina/química , Agonistas do Receptor de Serotonina/farmacologia , Linhagem Celular , Humanos , Pirimidinas/síntese química , Agonistas do Receptor de Serotonina/síntese química , Triazóis/síntese química , Triazóis/química , Triazóis/farmacologia
20.
J Med Chem ; 53(14): 5186-96, 2010 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-20560595

RESUMO

5-HT(6) receptors are exclusively localized in the CNS and have high affinity with many psychotropic agents. Though the role of this receptor in many CNS diseases is widely anticipated, lack of definite progress in the development of 5-HT(6) receptor-oriented drugs indicates a need for further discoveries of novel chemotypes with high potency and high selectivity to the receptor. Here we present preparations and biological evaluation of a series of (3-phenylsulfonylcycloalkano[e and d]pyrazolo[1,5-a]pyrimidin-2-yl)amines. Phenylsulfonylcyclopentapyrazolopyrimidine 7 was found to be a highly selective 5-HT(6) receptor antagonist with high affinity (low picomolar range) and potency. 7 and a few of its analogues were further tested for biological effect on 5-HT(2B) receptors and hERG potassium channels, potential liability targets. Such liability appears to be minimal, based on the in vitro data.


Assuntos
Aminas/síntese química , Pirazóis/síntese química , Pirimidinas/síntese química , Receptores de Serotonina/metabolismo , Antagonistas da Serotonina/síntese química , Sulfonas/síntese química , Aminas/química , Aminas/farmacologia , Linhagem Celular , Cristalografia por Raios X , Canal de Potássio ERG1 , Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , Humanos , Modelos Moleculares , Estrutura Molecular , Pirazóis/química , Pirazóis/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Ensaio Radioligante , Antagonistas do Receptor 5-HT2 de Serotonina , Antagonistas da Serotonina/química , Antagonistas da Serotonina/farmacologia , Relação Estrutura-Atividade , Sulfonas/química , Sulfonas/farmacologia
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