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2.
Cell ; 157(6): 1393-1404, 2014 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-24856969

RESUMO

Voltage-gated sodium (NaV) channels control the upstroke of the action potentials in excitable cells. Multiple studies have shown distinct roles of NaV channel subtypes in human physiology and diseases, but subtype-specific therapeutics are lacking and the current efforts have been limited to small molecules. Here, we present a monoclonal antibody that targets the voltage-sensor paddle of NaV1.7, the subtype critical for pain sensation. This antibody not only inhibits NaV1.7 with high selectivity, but also effectively suppresses inflammatory and neuropathic pain in mice. Interestingly, the antibody inhibits acute and chronic itch despite well-documented differences in pain and itch modulation. Using this antibody, we discovered that NaV1.7 plays a key role in spinal cord nociceptive and pruriceptive synaptic transmission. Our studies reveal that NaV1.7 is a target for itch management, and the antibody has therapeutic potential for suppressing pain and itch. Our antibody strategy may have broad applications for voltage-gated cation channels.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Canal de Sódio Disparado por Voltagem NAV1.7/metabolismo , Dor/tratamento farmacológico , Prurido/tratamento farmacológico , Transmissão Sináptica/efeitos dos fármacos , Bloqueadores do Canal de Sódio Disparado por Voltagem/uso terapêutico , Sequência de Aminoácidos , Animais , Células HEK293 , Humanos , Inflamação/induzido quimicamente , Inflamação/patologia , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Canal de Sódio Disparado por Voltagem NAV1.7/química , Neurônios/metabolismo , Alinhamento de Sequência , Medula Espinal/metabolismo
3.
Proc Natl Acad Sci U S A ; 121(28): e2320796121, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38959036

RESUMO

Phoresy is an interspecies interaction that facilitates spatial dispersal by attaching to a more mobile species. Hitchhiking species have evolved specific traits for physical contact and successful phoresy, but the regulatory mechanisms involved in such traits and their evolution are largely unexplored. The nematode Caenorhabditis elegans displays a hitchhiking behavior known as nictation during its stress-induced developmental stage. Dauer-specific nictation behavior has an important role in natural C. elegans populations, which experience boom-and-bust population dynamics. In this study, we investigated the nictation behavior of 137 wild C. elegans strains sampled throughout the world. We identified species-wide natural variation in nictation and performed a genome-wide association mapping. We show that the variants in the promoter of nta-1, encoding a putative steroidogenic enzyme, underlie differences in nictation. This difference is due to the changes in nta-1 expression in glial cells, which implies that glial steroid metabolism regulates phoretic behavior. Population genetic analysis and geographic distribution patterns suggest that balancing selection maintained two nta-1 haplotypes that existed in ancestral C. elegans populations. Our findings contribute to further understanding of the molecular mechanism of species interaction and the maintenance of genetic diversity within natural populations.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Neuroglia , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Neuroglia/metabolismo , Estudo de Associação Genômica Ampla , Comportamento Animal/fisiologia , Variação Genética , Regiões Promotoras Genéticas/genética , Esteroides/metabolismo , Esteroides/biossíntese
4.
Genome Res ; 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37918961

RESUMO

Telomeres are composed of tandem arrays of telomeric-repeat motifs (TRMs) and telomere-binding proteins (TBPs), which are responsible for ensuring end-protection and end-replication of chromosomes. TRMs are highly conserved owing to the sequence specificity of TBPs, although significant alterations in TRM have been observed in several taxa, except Nematoda. We used public whole-genome sequencing data sets to analyze putative TRMs of 100 nematode species and determined that three distinct branches included specific novel TRMs, suggesting that evolutionary alterations in TRMs occurred in Nematoda. We focused on one of the three branches, the Panagrolaimidae family, and performed a de novo assembly of four high-quality draft genomes of the canonical (TTAGGC) and novel TRM (TTAGAC) isolates; the latter genomes revealed densely clustered arrays of the novel TRM. We then comprehensively analyzed the subtelomeric regions of the genomes to infer how the novel TRM evolved. We identified DNA damage-repair signatures in subtelomeric sequences that were representative of consequences of telomere maintenance mechanisms by alternative lengthening of telomeres. We propose a hypothetical scenario in which TTAGAC-containing units are clustered in subtelomeric regions and pre-existing TBPs capable of binding both canonical and novel TRMs aided the evolution of the novel TRM in the Panagrolaimidae family.

5.
Nature ; 575(7784): 634-638, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31776489

RESUMO

Quantum dot (QD) light-emitting diodes (LEDs) are ideal for large-panel displays because of their excellent efficiency, colour purity, reliability and cost-effective fabrication1-4. Intensive efforts have produced red-, green- and blue-emitting QD-LEDs with efficiencies of 20.5 per cent4, 21.0 per cent5 and 19.8 per cent6, respectively, but it is still desirable to improve the operating stability of the devices and to replace their toxic cadmium composition with a more environmentally benign alternative. The performance of indium phosphide (InP)-based materials and devices has remained far behind those of their Cd-containing counterparts. Here we present a synthetic method of preparing a uniform InP core and a highly symmetrical core/shell QD with a quantum yield of approximately 100 per cent. In particular, we add hydrofluoric acid to etch out the oxidative InP core surface during the growth of the initial ZnSe shell and then we enable high-temperature ZnSe growth at 340 degrees Celsius. The engineered shell thickness suppresses energy transfer and Auger recombination in order to maintain high luminescence efficiency, and the initial surface ligand is replaced with a shorter one for better charge injection. The optimized InP/ZnSe/ZnS QD-LEDs showed a theoretical maximum external quantum efficiency of 21.4 per cent, a maximum brightness of 100,000 candelas per square metre and an extremely long lifetime of a million hours at 100 candelas per square metre, representing a performance comparable to that of state-of-the-art Cd-containing QD-LEDs. These as-prepared InP-based QD-LEDs could soon be usable in commercial displays.

6.
Mol Cell Proteomics ; 22(2): 100479, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36481452

RESUMO

Neuropeptides regulate animal physiology and behavior, making them widely studied targets of functional genetics research. While the field often relies on differential -omics approaches to build hypotheses, no such method exists for neuropeptidomics. It would nonetheless be valuable for studying behaviors suspected to be regulated by neuropeptides, especially when little information is otherwise available. This includes nictation, a phoretic strategy of Caenorhabditis elegans dauers that parallels host-finding strategies of infective juveniles of many pathogenic nematodes. We here developed a targeted peptidomics method for the model organism C. elegans and show that 161 quantified neuropeptides are more abundant in its dauer stage compared with L3 juveniles. Many of these have orthologs in the commercially relevant pathogenic nematode Steinernema carpocapsae, in whose infective juveniles, we identified 126 neuropeptides in total. Through further behavioral genetics experiments, we identify flp-7 and flp-11 as novel regulators of nictation. Our work advances knowledge on the genetics of nictation behavior and adds comparative neuropeptidomics as a tool to functional genetics workflows.


Assuntos
Proteínas de Caenorhabditis elegans , Nematoides , Neuropeptídeos , Animais , Caenorhabditis elegans , Nematoides/fisiologia , Espectrometria de Massas
7.
Nucleic Acids Res ; 51(17): 9122-9143, 2023 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-37496110

RESUMO

Telomere length must be maintained in actively dividing cells to avoid cellular arrest or death. In the absence of telomerase activity, activation of alternative lengthening of telomeres (ALT) allows the maintenance of telomeric length and prolongs the cellular lifespan. Our previous studies have established two types of ALT survivors from mouse embryonic stem cells. The key differences between these ALT survivors are telomere-constituting sequences: non-telomeric sequences and canonical telomeric repeats, with each type of ALT survivors being referred to as type I and type II, respectively. We explored how the characteristics of the two types of ALT lines reflect their fates using multi-omics approaches. The most notable gene expression signatures of type I and type II ALT cell lines were chromatin remodelling and DNA repair, respectively. Compared with type II cells, type I ALT cells accumulated more mutations and demonstrated persistent telomere instability. These findings indicate that cells of the same origin have separate routes for survival, thus providing insights into the plasticity of crisis-suffering cells and cancers.


Assuntos
Células-Tronco Embrionárias Murinas , Telomerase , Animais , Camundongos , Células-Tronco Embrionárias Murinas/metabolismo , Mutação , Telomerase/genética , Telomerase/metabolismo , Telômero/genética , Telômero/metabolismo , Homeostase do Telômero
8.
Proc Natl Acad Sci U S A ; 119(6)2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35101981

RESUMO

One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global ground-sourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are ∼73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness.


Assuntos
Conservação dos Recursos Naturais , Florestas , Árvores/classificação , Planeta Terra , Árvores/crescimento & desenvolvimento
9.
J Am Chem Soc ; 146(15): 10251-10256, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38587307

RESUMO

While the shape-dependent quantum confinement (QC) effect in anisotropic semiconductor nanocrystals has been extensively studied, the QC in facet-specified polyhedral quantum dots (QDs) remains underexplored. Recently, tetrahedral nanocrystals have gained prominence in III-V nanocrystal synthesis. In our study, we successfully synthesized well-faceted tetrahedral InAs QDs with a first excitonic absorption extending up to 1700 nm. We observed an unconventional sizing curve, indicating weaker confinement than for equivalently volumed spherical QDs. The (111) surface states of InAs QDs persist at the conduction band minimum state even after ligand passivation with a significantly reduced band gap, which places tetrahedral QDs at lower energies in the sizing curve. Consequently, films composed of tetrahedral QDs demonstrate an extended photoresponse into the short-wave infrared region, compared to isovolume spherical QD films.

10.
Epidemiol Infect ; 152: e76, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38639116

RESUMO

This study aimed to investigate the diverse clinical manifestations and simple early biomarkers predicting mortality of COVID-19 patients admitted to the emergency department (ED). A total of 710 patients with COVID-19 were enrolled from 6,896 patients presenting to the ED between January 2022 and March 2022. During the study period, a total of 478 patients tested positive for COVID-19, among whom 222 (46.4%) presented with extrapulmonary manifestations of COVID-19; 49 (10.3%) patients displayed gastrointestinal manifestations, followed by neurological (n = 41; 8.6%) and cardiac manifestations (n = 31; 6.5%). In total, 54 (11.3%) patients died. A Cox proportional hazards model revealed that old age, acute kidney injury at presentation, increased total leukocyte counts, low platelet counts, decreased albumin levels, and increased LDH levels were the independent predictors of mortality. The albumin levels exhibited the highest area under the curve in receiver operating characteristic analysis, with a value of 0.860 (95% confidence interval, 0.796-0.875). The study showed the diverse clinical presentations and simple-to-measure prognostic markers in COVID-19 patients presenting to the ED. Serum albumin levels can serve as a novel and simple early biomarker to identify COVID-19 patients at high risk of death.


Assuntos
Biomarcadores , COVID-19 , Serviço Hospitalar de Emergência , Humanos , COVID-19/mortalidade , COVID-19/sangue , COVID-19/diagnóstico , Serviço Hospitalar de Emergência/estatística & dados numéricos , Masculino , Feminino , Biomarcadores/sangue , Pessoa de Meia-Idade , Idoso , Adulto , SARS-CoV-2 , Prognóstico , Idoso de 80 Anos ou mais , Albumina Sérica/análise , Estudos Retrospectivos , Modelos de Riscos Proporcionais
11.
Demography ; 61(3): 711-735, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38767569

RESUMO

Despite the persistence of relationships between historical racist violence and contemporary Black-White inequality, research indicates, in broad strokes, that the slavery-inequality relationship in the United States has changed over time. Identifying the timing of such change across states can offer insights into the underlying processes that generate Black-White inequality. In this study, we use integrated nested Laplace approximation models to simultaneously account for spatial and temporal features of panel data for Southern counties during the period spanning 1900 to 2018, in combination with data on the concentration of enslaved people from the 1860 census. Results provide the first evidence on the timing of changes in the slavery-economic inequality relationship and how changes differ across states. We find a region-wide decline in the magnitude of the slavery-inequality relationship by 1930, with declines traversing the South in a northeasterly-to-southwesterly pattern over the study period. Different paces in declines in the relationship across states suggest the expansion of institutionalized racism first in places with the longest-standing overt systems of slavery. Results provide guidance for further identifying intervening mechanisms-most centrally, the maturity of racial hierarchies and the associated diffusion of racial oppression across institutions, and how they affect the legacy of slavery in the United States.


Assuntos
Negro ou Afro-Americano , Escravização , Racismo , Fatores Socioeconômicos , Humanos , Escravização/história , Estados Unidos , Racismo/estatística & dados numéricos , Negro ou Afro-Americano/estatística & dados numéricos , História do Século XX , Análise Espaço-Temporal , População Branca/estatística & dados numéricos , História do Século XXI , História do Século XIX , Pessoas Escravizadas/estatística & dados numéricos , Pessoas Escravizadas/história
12.
Nano Lett ; 23(13): 6269-6275, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37099317

RESUMO

Tailoring the electrical properties of one-dimensional (1D) van der Waals (vdW) materials is desirable for their applications toward electronic devices by exploiting their unique characteristics. However, 1D vdW materials have not been extensively investigated for modulation of their electrical properties. Here we control doping levels and types of 1D vdW Nb2Pd3Se8 over a wide energy range by immersion in AuCl3 or ß-nicotinamide adenine dinucleotide (NADH) solutions, respectively. Through spectroscopic analyses and electrical characterizations, we confirm that the charges were effectively transferred to Nb2Pd3Se8, and the dopant concentration was adjusted to the immersion time. Furthermore, we make the axial p-n junction of 1D Nb2Pd3Se8 by a selective area p-doping using the AuCl3 solution, which exhibits rectifying behavior with an Iforward/Ireverse of 81 and an ideality factor of 1.2. Our findings could pave the way to more practical and functional electronic devices based on 1D vdW materials.

13.
Int J Mol Sci ; 25(2)2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38256144

RESUMO

As the global population ages, the prevalence of Parkinson's disease (PD) is steadily on the rise. PD demonstrates chronic and progressive characteristics, and many cases can transition into dementia. This increases societal and economic burdens, emphasizing the need to find effective treatments. Among the widely recognized causes of PD is the abnormal accumulation of proteins, and autophagy dysfunction accelerates this accumulation. The resultant Lewy bodies are also commonly found in Alzheimer's disease patients, suggesting an increased potential for the onset of dementia. Additionally, the production of free radicals due to mitochondrial dysfunction contributes to neuronal damage and degeneration. The activation of astrocytes and the M1 phenotype of microglia promote damage to dopamine neurons. The drugs currently used for PD only delay the clinical progression and exacerbation of the disease without targeting its root cause, and come with various side effects. Thus, there is a demand for treatments with fewer side effects, with much potential offered by natural products. In this study, we reviewed a total of 14 articles related to herbal medicines and natural products and investigated their relevance to possible PD treatment. The results showed that the reviewed herbal medicines and natural products are effective against lysosomal disorder, mitochondrial dysfunction, and inflammation, key mechanisms underlying PD. Therefore, natural products and herbal medicines can reduce neurotoxicity and might improve both motor and non-motor symptoms associated with PD. Furthermore, these products, with their multi-target effects, enhance bioavailability, inhibit antibiotic resistance, and might additionally eliminate side effects, making them good alternative therapies for PD treatment.


Assuntos
Doença de Alzheimer , Produtos Biológicos , Doenças Mitocondriais , Doença de Parkinson , Plantas Medicinais , Humanos , Doença de Parkinson/tratamento farmacológico , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Extratos Vegetais
14.
BMC Genomics ; 24(1): 148, 2023 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-36973656

RESUMO

BACKGROUND: Recent advances in long-read sequencing technologies have enabled accurate identification of all genetic variants in individuals or cells; this procedure is known as variant calling. However, benchmarking studies on variant calling using different long-read sequencing technologies are still lacking. RESULTS: We used two Caenorhabditis elegans strains to measure several variant calling metrics. These two strains shared true-positive genetic variants that were introduced during strain generation. In addition, both strains contained common and distinguishable variants induced by DNA damage, possibly leading to false-positive estimation. We obtained accurate and noisy long reads from both strains using high-fidelity (HiFi) and continuous long-read (CLR) sequencing platforms, and compared the variant calling performance of the two platforms. HiFi identified a 1.65-fold higher number of true-positive variants on average, with 60% fewer false-positive variants, than CLR did. We also compared read-based and assembly-based variant calling methods in combination with subsampling of various sequencing depths and demonstrated that variant calling after genome assembly was particularly effective for detection of large insertions, even with 10 × sequencing depth of accurate long-read sequencing data. CONCLUSIONS: By directly comparing the two long-read sequencing technologies, we demonstrated that variant calling after genome assembly with 10 × or more depth of accurate long-read sequencing data allowed reliable detection of true-positive variants. Considering the high cost of HiFi sequencing, we herein propose appropriate methodologies for performing cost-effective and high-quality variant calling: 10 × assembly-based variant calling. The results of the present study may facilitate the development of methods for identifying all genetic variants at the population level.


Assuntos
Benchmarking , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Análise de Sequência de DNA/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos
15.
Neurobiol Dis ; 177: 105982, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36592864

RESUMO

Neuregulin-1 (NRG1) is an epidermal growth factor family member with essential roles in the developing and adult nervous systems. In recent years, establishing evidence has collectively suggested that NRG1 is a new modulator of central nervous system (CNS) injury and disease, with multifaceted roles in neuroprotection, remyelination, neuroinflammation, and other repair mechanisms. NRG1 signaling exerts its effects via the tyrosine kinase receptors ErbB2-ErbB4. The NRG1/ErbB network in CNS pathology and repair has evolved, primarily in recent years. In the present study, we demonstrated that a unilateral microinjection of CoCl2 into the ventral hippocampus (vHPC) induced hypoxic insult and led to anxiety-related behaviors and deficit sociability in mice. NRG1 treatment significantly alleviated the CoCl2-induced increase of hypoxic-related molecules and behavioral abnormalities. Furthermore, NRG1 reduced the CoCl2-induced neuroinflammation and neuronal deficits in the vHPC or primary hippocampal neurons in mice. Collectively, these results suggest that NRG1 ameliorates hypoxia by alleviating synaptic deficits and behavioral abnormalities of the CoCl2-induced vHPC hypoxic model.


Assuntos
Neuregulina-1 , Doenças Neuroinflamatórias , Camundongos , Animais , Neuregulina-1/metabolismo , Hipocampo/metabolismo , Comportamento Social , Ansiedade/tratamento farmacológico
16.
Cogn Psychol ; 143: 101565, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37156123

RESUMO

The present paper reports an experiment with a two-year-delayed (M = 695 days) follow-up that tests an approach to raising willingness to take political and personal climate actions. Many Americans still do not view climate change as a threat requiring urgent action. Moreover, among American conservatives, higher science literacy is paradoxically associated with higher anthropogenic climate-change skepticism. Our experimental materials were designed to harness the power of two central cognitive constraints - coherence and causal invariance, which map onto two narrative proclivities that anthropologists have identified as universal - to promote climate action across the political spectrum. Towards that goal, the essential role of these constraints in the causal-belief-formation process predicts that climate-change information would be more persuasive when it is embedded in a personal climate-action narrative, the evocation of which can benefit from exposure to parsimonious scientific explanations of indisputable everyday observations, juxtaposed with reasoners' own, typically less coherent explanations, occurring in a context that engages their moral stance. Our brief one-time intervention, conducted in ten U.S. states with the highest level of climate skepticism, showed that across the political spectrum, our materials raised appreciation of science, openness to alternative views, and willingness to take climate actions in the immediate assessment. It also raised how likely were reports two years later of having taken those actions or would have taken them had the opportunity existed, suggesting a long-lasting effect. Our approach adopts the framework that conceptions of reality are representations, and adaptive solutions in that infinite space of representations require cognitive constraints to narrow the search.


Assuntos
Mudança Climática , Motivação , Humanos , Estados Unidos , Cognição
17.
Vet Res ; 54(1): 72, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37658425

RESUMO

The circulation of carbapenemase-producing Escherichia coli (CPEC) in our society is a serious concern for vulnerable patients in nosocomial environments. However, the genomic epidemiology of the circulation of CPEC bacteria among companion animals remains largely unknown. In this study, epidemiological analysis was conducted using complete genome identification of CPEC ST410 isolates obtained from companion animals. To estimate the genomic distance and relatedness of the isolates, a total of 37 whole-genome datasets of E. coli ST410 strains were downloaded and comparatively analysed. As a result of the analysis, the genomic structure of the chromosomes and plasmids was identified, revealing the genomic positions of multiple resistance and virulence genes. The isolates in this study were grouped into the subclade H24/RxC, with fimH24, and substituted quinolone resistance-determining regions (QRDRs) and multiple beta-lactamases, including extended-spectrum ß-lactamase (ESBL) and carbapenemase. In addition, the in silico comparison of the whole-genome datasets revealed unidentified ST410 H24/Rx subgroups, including either high pathogenicity islands (HPIs) or H21 serotypes. Considering the genetic variations and resistance gene dissemination of the isolates carried by companion animals, future approaches for preventive measurement must include the "One Health" perspective for public health in our society.


Assuntos
Escherichia coli , Genômica , Animais , Epidemiologia Molecular , Escherichia coli/genética , beta-Lactamases/genética
18.
J Phys Chem A ; 127(28): 5815-5822, 2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37432658

RESUMO

We re-examined the existence of planar tetracoordinate F (ptF) atoms, which was proposed recently by using high-level ab initio methods such as coupled-cluster singles and doubles with perturbative triples (CCSD(T)) with large basis sets. Our calculations indicate that the planar structures of FIn4+ (D4h), FTl4+ (D4h), FGaIn3+ (C2V), FIn2Tl2+ (D2h), FIn3Tl+ (C2V), and FInTl3+ (C2V) are not the minimum energy states; by contrast, they are transition states. Density functional theory calculations overestimate the size of the cavity formed by the four peripheral atoms, leading to erroneous conclusions regarding the existence of ptF atoms. Our analysis suggests that the preference for non-planar structures in the six cations studied is not due to the pseudo Jahn-Teller effect. Additionally, spin-orbit coupling does not alter the main conclusion that the ptF atom does not exist. If sufficiently large cavity formation by group 13 elements to accommodate the central F- ion is guaranteed, then the existence of ptF atoms is plausible.

19.
Appl Microbiol Biotechnol ; 107(20): 6205-6217, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37642718

RESUMO

Naringin found in citrus fruits is a flavanone glycoside with numerous biological activities. However, the bitterness, low water-solubility, and low bioavailability of naringin are the main issues limiting its use in the pharmaceutical and nutraceutical industries. Herein, a glucansucrase from isolated Leuconostoc citreum NY87 was used for trans-α-glucosylattion of naringin by using sucrose as substrate. Two naringin glucosides (O-α-D-glucosyl-(1'''' → 6″) naringin (compound 1) and 4'-O-α-D-glucosyl naringin (compound 2)) were purified and determined their structures by nuclear magnetic resonance. The optimization condition for the synthesis of compound 1 was obtained at 10 mM naringin, 200 mM sucrose, and 337.5 mU/mL at 28 °C for 24 h by response surface methodology method. Compound 1 and compound 2 showed 1896- and 3272 times higher water solubility than naringin. Furthermore, the bitterness via the human bitter taste receptor TAS2R39 displayed that compound 1 was reduced 2.9 times bitterness compared with naringin, while compound 2 did not express bitterness at 1 mM. Both compounds expressed higher neuroprotective effects than naringin on human neuroblastoma SH-SY5Y cells treated with 5 mM scopolamine based on cell viability and cortisol content. Compound 1 reduced acetylcholinesterase activity more than naringin and compound 2. These results indicate that naringin glucosides could be utilized as functional material in the nutraceutical and pharmaceutical industries. KEY POINTS: • A novel O-α-D-glucosyl-(1 → 6) naringin was synthesized using glucansucrase from L. citreum NY87. • Naringin glucosides improved water-solubility and neuroprotective effects on SH-SY5Y cells. • Naringin glucosides showed a decrease in bitterness on bitter taste receptor 39.


Assuntos
Flavanonas , Neuroblastoma , Fármacos Neuroprotetores , Humanos , Fármacos Neuroprotetores/farmacologia , Solubilidade , Acetilcolinesterase , Flavanonas/farmacologia , Sacarose/química , Glucosídeos/farmacologia , Glucosídeos/química , Água , Receptores de Superfície Celular
20.
J Chem Phys ; 158(15)2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37094019

RESUMO

Discovery of a new oxidation state for an element expands its chemistry. A high oxidation state, such as +7, is rare for sp-block elements except for halogens. In this study, we determined that Te can attain a +7 oxidation state through the existence of a distorted octahedron (DOH) structure of TeCl6+ based on coupled cluster singles and doubles with perturbative triples calculations. We propose a new type of isomerization that resembles pseudorotation. The octahedron structure of TeF6+ bearing one elongated axial bond isomerizes to a DOH via an associated pseudorotation.

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