Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Huan Jing Ke Xue ; 43(8): 3953-3965, 2022 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-35971694

RESUMO

Air pollution in Henan province is serious and is significantly impacted by pollution transmission and interactions with surrounding areas. The emission sources in 18 cities in Henan province were labeled and applied to the WRF-CMAQ traceability model for simulation in January, April, July, and October of 2017. The pollutant distribution results showed that due to the combined influence of emissions and meteorology, the concentrations of PM2.5, NO2, and SO2 in Henan province were the highest in winter and the lowest in summer. The seasonal variation in O3-8h concentration was the highest in summer, followed by spring, and the lowest in winter. There was a large difference in pollutant concentrations between different seasons. The average concentrations of PM2.5, NO2, and SO2 in winter in Henan province were 4.17, 4.12, and 6.24 times those in summer, respectively, whereas the concentration of O3-8h in summer was 2.24 times that in winter. Since PM2.5, NO2, and SO2 are closely related to primary emissions and have a certain homology, the distributions of high values of these three pollutants were higher in the north and lower in the south, and the seasonal trends were more consistent. The seasonal distribution of O3-8h varied widely, with high O3-8h values mainly distributed in the northeastern region of Henan province in summer, when meteorological conditions contributed to O3 production; in winter, spring, and autumn, high O3-8h values were mainly distributed in the southern part of Henan province due to the suppression of meteorological conditions and NOx consumption. The results of the study on the transport of pollutants showed that extra-provincial transport and natural sources contributed the most to the concentrations of PM2.5, O3-8h, NO2, and SO2 in winter, with 36.20%-72.32%, 77.96%-96.08%, 49.45%-78.80%, and 59.05%-88.85%, respectively. When considering only local emissions and intra-provincial transmission, the contributions of emissions to local concentrations of the four pollutants in summer were the highest in all cities of Henan province. The contributions of intra-provincial transmission to PM2.5 and O3-8h in spring were the largest, with 25.63%-74.69% and 30.21%-80.01%, respectively, and the contributions of intra-provincial transmission to NO2 and SO2 in winter were larger, with 26.02%-76.96% and 20.30%-82.34%. The transmission paths of PM2.5, NO2, and SO2 were more similar in Henan province, with more transmission from north to south in winter, from west to east and southwest to northeast in spring, from southwest to northeast in summer, and from north to south in autumn; however, the transmission of PM2.5 was more complicated. The O3-8h transport path was more different from the others, especially in autumn when pollutants were mostly transported from north to south, but the O3-8h transport path from southwest to northeast was obvious.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , China , Cidades , Monitoramento Ambiental/métodos , Dióxido de Nitrogênio , Material Particulado/análise , Estações do Ano
2.
J Nat Prod ; 84(4): 1175-1184, 2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33760626

RESUMO

Porcine epidemic diarrhea virus (PEDV) has become increasingly problematic around the world, not only for its hazards to livestock but also due to the possibility that it is a zoonotic disease. Although vaccine therapy has made some progress toward PEDV control, additional effective therapeutic strategies against PEDV are needed, such as the development of chemotherapeutic agents. The aim of this work was to identify novel anti-PEDV agents by designing and synthesizing a series of phenanthridine derivatives. Among them, three compounds (compounds 1, 2, and 4) were identified as potent anti-PEDV agents exhibiting suppression of host cell heat shock cognate 70 (Hsc70) expression. Mechanism studies revealed that host Hsc70 is involved in the replication of PEDV, and its expression can be suppressed by destabilization of the mRNA, resulting in inhibition of PEDV replication. Activity against PEDV in vivo in PEDV-infected piglets suggested that phenanthridine derivatives are the first host-acting potential anti-PEDV agents.


Assuntos
Antivirais/farmacologia , Proteínas de Choque Térmico HSC70/metabolismo , Fenantridinas/farmacologia , Vírus da Diarreia Epidêmica Suína/efeitos dos fármacos , Animais , Antivirais/síntese química , Linhagem Celular , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/veterinária , Desenho de Fármacos , Estrutura Molecular , Fenantridinas/síntese química , Suínos
4.
J Agric Food Chem ; 66(18): 4621-4629, 2018 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-29669412

RESUMO

Two novel flavoalkaloids, (-)-6-(5'''- S)- N-ethyl-2-pyrrolidinone-epigallocatechin- O-gallate (ester-type catechin pyrrolidinone A, etc-pyrrolidinone A, 1), (-)-6-(5'''- R)- N-ethyl-2-pyrrolidinone-epigallocatechin- O-gallate (etc-pyrrolidinone B, 2), and new naturally occurring flavoalkaloids, (-)-8- N-ethyl-2-pyrrolidinone-epigallocatechin- O-gallate (etc-pyrrolidinone C, 3a, and etc- pyrrolidinone D, 3b), were isolated from white tea ( Camellia sinensis). Their structures were identified by extensive nuclear magnetic resonance spectra. The absolute configuration of compounds 1 and 2 was decided by comprehensive circular dichroism spectroscopic analyses. The isolated flavoalkaloids together with (-)-epigallocatechin- O-gallate (EGCG) were evaluated for their inhibition against the formation of advanced glycation end products, with IC50 values ranging from 10.3 to 25.3 µM. Ultra performance liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry detected these flavoalkaloids in both white tea and fresh tea leaves, which demonstrated the existence of a corresponding biosynthetic pathway in tea plants. Therefore, a possible pathway was proposed to involve deamination, decarboxylation, and spontaneously cyclization of l-theanine and then attachment of the product to EGCG to form the flavoalkaloids.


Assuntos
Alcaloides/química , Camellia sinensis/química , Flavonoides/química , Produtos Finais de Glicação Avançada/química , Extratos Vegetais/química , Alcaloides/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Flavonoides/isolamento & purificação , Estrutura Molecular , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Espectrometria de Massas por Ionização por Electrospray
5.
BMC Plant Biol ; 14: 243, 2014 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-25224438

RESUMO

BACKGROUND: Tea is one of the most consumed beverages worldwide. The healthy effects of tea are attributed to a wealthy of different chemical components from tea. Thousands of studies on the chemical constituents of tea had been reported. However, data from these individual reports have not been collected into a single database. The lack of a curated database of related information limits research in this field, and thus a cohesive database system should necessarily be constructed for data deposit and further application. DESCRIPTION: The Tea Metabolome database (TMDB), a manually curated and web-accessible database, was developed to provide detailed, searchable descriptions of small molecular compounds found in Camellia spp. esp. in the plant Camellia sinensis and compounds in its manufactured products (different kinds of tea infusion). TMDB is currently the most complete and comprehensive curated collection of tea compounds data in the world. It contains records for more than 1393 constituents found in tea with information gathered from 364 published books, journal articles, and electronic databases. It also contains experimental 1H NMR and 13C NMR data collected from the purified reference compounds or collected from other database resources such as HMDB. TMDB interface allows users to retrieve tea compounds entries by keyword search using compound name, formula, occurrence, and CAS register number. Each entry in the TMDB contains an average of 24 separate data fields including its original plant species, compound structure, formula, molecular weight, name, CAS registry number, compound types, compound uses including healthy benefits, reference literatures, NMR, MS data, and the corresponding ID from databases such as HMDB and Pubmed. Users can also contribute novel regulatory entries by using a web-based submission page. The TMDB database is freely accessible from the URL of http://pcsb.ahau.edu.cn:8080/TCDB/index.jsp. The TMDB is designed to address the broad needs of tea biochemists, natural products chemists, nutritionists, and members of tea related research community. CONCLUSION: The TMDB database provides a solid platform for collection, standardization, and searching of compounds information found in tea. As such this database will be a comprehensive repository for tea biochemistry and tea health research community.


Assuntos
Bases de Dados Factuais , Chá/química , Metaboloma , Interface Usuário-Computador
6.
PLoS One ; 9(2): e87980, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24498419

RESUMO

Streptococcus agalactiae, long recognized as a mammalian pathogen, is an emerging concern with regard to fish. In this study, we used a mouse model and in vitro cell infection to evaluate the pathogenetic characteristics of S. agalactiae GD201008-001, isolated from tilapia in China. This bacterium was found to be highly virulent and capable of inducing brain damage by migrating into the brain by crossing the blood-brain barrier (BBB). The phagocytosis assays indicated that this bacterium could be internalized by murine macrophages and survive intracellularly for more than 24 h, inducing injury to macrophages. Further, selective capture of transcribed sequences (SCOTS) was used to investigate microbial gene expression associated with intracellular survival. This positive cDNA selection technique identified 60 distinct genes that could be characterized into 6 functional categories. More than 50% of the differentially expressed genes were involved in metabolic adaptation. Some genes have previously been described as associated with virulence in other bacteria, and four showed no significant similarities to any other previously described genes. This study constitutes the first step in further gene expression analyses that will lead to a better understanding of the molecular mechanisms used by S. agalactiae to survive in macrophages and to cross the BBB.


Assuntos
Genes Bacterianos/genética , Macrófagos/microbiologia , Infecções Estreptocócicas/microbiologia , Streptococcus agalactiae/genética , Virulência/genética , Animais , Biomarcadores/metabolismo , Barreira Hematoencefálica/microbiologia , Barreira Hematoencefálica/patologia , DNA Bacteriano/metabolismo , Perfilação da Expressão Gênica , Técnicas Imunoenzimáticas , Camundongos , Camundongos Endogâmicos BALB C , Análise de Sequência com Séries de Oligonucleotídeos , Fagocitose , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Infecções Estreptocócicas/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...