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1.
Bioorg Chem ; 138: 106619, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37253310

RESUMO

Three new diterpenoids with an unusual carbon skeleton, pedilanins A-C (1-3), and nine new jatrophane diterpenoids, pedilanins D-L (4-12), along with five known ones (13-17), were isolated from Pedilanthus tithymaloides. Compounds 1-3 characterize an unprecedented tricyclo[10.3.0.02,9]pentadecane skeleton. Compounds 4-8 are rare examples of the jatrophanes bearing a cyclic hemiketal substructure. Their structures were determined by an extensive analysis of HRESIMS, NMR, quantum-chemical calculation, DP4+ probability, and X-ray crystallographic data. In the bioassay, compounds 1-12 dramatically reversed multidrug resistance in cancer cells with the fold-reversals ranging from 17.9 to 396.8 at the noncytotoxic concentration of 10 µM. The mechanism results indicated that compounds 2 and 3 inhibited the P-glycoprotein (Pgp) transporter function, thus reversing the drug resistance.


Assuntos
Diterpenos , Euphorbia , Estrutura Molecular , Euphorbia/química , Resistência a Múltiplos Medicamentos , Compostos Radiofarmacêuticos/farmacologia , Diterpenos/farmacologia , Diterpenos/química
2.
Oncol Rep ; 45(3): 1235-1248, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33650672

RESUMO

Breast cancer is the most common type of cancer amongst women worldwide, and numerous microRNAs (miRNAs/miRs) are involved in the initiation and progression of breast cancer. The aim of the present study was to identify hub miRNAs and determine the underlying mechanisms regulated by these miRNAs in breast cancer. Breast invasive carcinoma transcriptome data (including mRNAs and miRNAs), and clinical data were acquired from The Cancer Genome Atlas database. Differential gene expression analysis, co­expression network analysis, gene set enrichment analysis (GSEA) and prognosis analysis were used to screen the hub miRNAs and explore their functions. Functional experiments were used to determine the underlying mechanisms of the hub miRNAs in breast cancer cells. The results revealed that low miR150 expression predicted a more advanced disease stage, and was associated with a less favorable prognosis. Through the combined use of five miRNA­target gene prediction tools, 31 potential miR150 target genes were identified. GSEA revealed that low miR150 expression was associated with the upregulation of several cancer­associated signaling pathways, and the downregulation of several tumor suppressor genes. Furthermore, miR150 independently affected overall survival in patients, and interacted with its target genes to indirectly affect overall and disease­free survival. Functional experiments demonstrated that miR150 positively regulated B and T lymphocyte attenuator (BTLA), and the downregulation of miR150 and BTLA combined promoted cell migration. In conclusion, the present study revealed that low miR150 expression was associated with less favorable clinical features, upregulation of several carcinogenic signaling pathways, and poor patient survival. Additionally, a miR150­BTLA axis was suggested to regulate cell viability and migration.


Assuntos
Neoplasias da Mama/genética , Carcinogênese/genética , MicroRNAs/genética , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Carcinogênese/patologia , Linhagem Celular Tumoral , Movimento Celular , Sobrevivência Celular , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/metabolismo , Prognóstico , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo , Transdução de Sinais , Análise de Sobrevida
3.
Food Sci Nutr ; 8(6): 2780-2788, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32566195

RESUMO

Dietary preferences were closely associated with the pathogenesis of numbers of metabolic disorders, in particularly, obesity. Dietary fiber was shown to be capable of preventing weight gain and excessive food intake mainly through stimulating chewing and saliva secretion, and promote satiety signals. In this study, we characterized the "Vitamin World® Vegan Meal" Formula of Feihe, a novel protein-enriched fiber dietary supplement contained potato protease inhibitor II (PI2) that developed. And we demonstrated that this particular fiber formula was effective in preventing weight gain, increasing satiety signals, and reducing food intake in rats in a dosage-dependent manner. Our study provides lines of evidence and would further bolster the use of this nutritious vegan meal in regulating satiety and food intake in clinics.

4.
Drug Des Devel Ther ; 14: 429-434, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32099327

RESUMO

BACKGROUND: Calycosin (CAL), a type of O-methylated isoflavone extracted from the herb Astralagusmembranaceus (AM), is a bioactive chemical with antioxidative, antiphlogistic and antineoplastic activities commonly used in traditional alternative Chinese medicine. AM has been shown to confer health benefits as an adjuvant in the treatment of a variety of diseases. AIM: The main objective of this study was to determine whether CAL influences the cytochrome P450 (CYP450) system involved in drug metabolism. METHODS: Midazolam, tolbutamide, omeprazole, metoprolol and phenacetin were selected as probe drugs. Rats were randomly divided into three groups, specifically, 5% Carboxymethyl cellulose (CMC) for 8 days (Control), 5% CMC for 7 days + CAL for 1 day (single CAL) and CAL for 8 days (conc CAL), and metabolism of the five probe drugs evaluated using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). RESULTS: No significant differences were observed for omeprazole and midazolam, compared to the control group. T max and t1/2 values of only one probe drug, phenacetin, in the conc CAL group were significantly different from those of the control group (T max h: 0.50±0.00 vs 0.23±0.15; control vs conc CAL). C max of tolbutamide was decreased about two-fold in the conc CAL treatment group (conc vs control: 219.48 vs 429.56, P<0.001). CONCLUSION: Calycosin inhibits the catalytic activities of CYP1A2, CYP2D6 and CYP2C9. Accordingly, we recommend caution, particularly when combining CAL as a modality therapy with drugs metabolized by CYP1A2, CYP2D6 and CYP2C9, to reduce the potential risks of drug accumulation or ineffective treatment.


Assuntos
Inibidores das Enzimas do Citocromo P-450/metabolismo , Medicamentos de Ervas Chinesas/metabolismo , Isoflavonas/metabolismo , Animais , Inibidores das Enzimas do Citocromo P-450/química , Inibidores das Enzimas do Citocromo P-450/farmacologia , Sistema Enzimático do Citocromo P-450/metabolismo , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Isoflavonas/química , Isoflavonas/farmacologia , Medicina Tradicional Chinesa , Metoprolol/química , Metoprolol/metabolismo , Midazolam/química , Midazolam/metabolismo , Omeprazol/química , Omeprazol/metabolismo , Fenacetina/química , Fenacetina/metabolismo , Ratos , Tolbutamida/química , Tolbutamida/metabolismo
5.
Chem Commun (Camb) ; 54(58): 8076-8079, 2018 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-29971275

RESUMO

A novel high-temperature dielectric and quadratic nonlinear optical switching material, 3,4-difluoroanilinium 18-crown-6 perchlorate, was synthesized. It exhibits two successive structural phase transitions at 347 K and 240 K, respectively. Gradually increased SHG-active characteristics are also identified.

6.
Iran J Basic Med Sci ; 21(4): 422-426, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29796228

RESUMO

OBJECTIVES: In this study, we aimed to evaluate the effect of salidroside on the activities of the different drug-metabolizing enzymes CYP1A2, CYP2B6, CYP2C9, CYP2D6 and CYP3A4 in rats, in which a specific probe drug was used for each enzyme. MATERIALS AND METHODS: After pretreatment with salidroside, five probe drugs were simultaneously administered to rats by gavage. The given dose was 2.0 mg/kg for phenacetin (CYP1A2 activity), 4.0 mg/kg for bupropion (CYP2B6 activity), 2.0 mg/kg for losartan (CYP2C9 activity), 8.0 mg/kg for metoprolol (CYP2D6 activity) and 1.0 mg/kg for midazolam (CYP3A4 activity). Then, an ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to analyze the concentrations of rats' blood, which were collected at different corresponding times. RESULTS: Our data showed that salidroside exhibited an inductive effect on CYP1A2, CYP2B6, CYP2C9 and CYP3A4 activities by changing the main pharmacokinetic parameters (t1/2, CL/F, Cmax and AUC(0-∞)) of the four probe drugs in rats. However, no significant changes in CYP2D6 activity were observed. CONCLUSION: In a word, the results displayed that salidroside could induce the activities of CYP1A2, CYP2B6, CYP2C9 and CYP3A4, which may influence the disposition of the drugs that are mainly metabolized by these pathways. Our research can provide the basis for the study of related herb-drug interactions in clinic.

9.
Environ Pollut ; 215: 187-194, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27203466

RESUMO

Anthropogenic impacts have continuously intensified in mega urban centers with increasing urbanization and growing population. The spatial distribution pattern of such impacts can be assessed with soil halogenated flame retardants (HFRs) as HFRs are mostly derived from the production and use of various consumer products. In the present study, soil samples were collected from the Pearl River Delta (PRD), a large urbanized region in southern China, and its surrounding areas and analyzed for a group of HFRs, i.e., polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane, bis(hexachlorocyclopentadieno)cyclooctane (DP) and hexabromobenzene. The sum concentrations of HFRs and PBDEs were in the ranges of 0.66-6500 and 0.37-5700 (mean: 290 and 250) ng g(-1) dry weight, respectively, around the middle level of the global range. BDE-209 was the predominant compound likely due to the huge amounts of usage and its persistence. The concentrations of HFRs were greater in the land-use types of residency, industry and landfill than in agriculture, forestry and drinking water source, and were also greater in the central PRD than in its surrounding areas. The concentrations of HFRs were moderately significantly (r(2) = 0.32-0.57; p < 0.05) correlated with urbanization levels, population densities and gross domestic productions in fifteen administrative districts. The spatial distribution of DP isomers appeared to be stereoselective as indicated by the similarity in the spatial patterns for the ratio of anti-DP versus the sum of DP isomers (fanti-DP) and DP concentrations. Finally, the concentrations of HFRs sharply decreased with increasing distance from an e-waste recycling site, indicating that e-waste derived HFRs largely remained in local soil.


Assuntos
Bromobenzenos/análise , Monitoramento Ambiental , Retardadores de Chama/análise , Éteres Difenil Halogenados/análise , Poluentes do Solo/análise , Urbanização , Poluentes Químicos da Água/análise , China , Cidades , Rios
10.
Eur J Drug Metab Pharmacokinet ; 41(1): 79-86, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25476996

RESUMO

We aimed at investigating the role of CYP2C9 in carvedilol O-desmethylation and identifying the effect of 35 CYP2C9 allelic variants we found in Chinese Han population on the in vitro metabolism of carvedilol. Recombinant CYP2C9 and CYP2D6 microsomes of the wild type were used to test and verify the enzymes involved in carvedilol O-desmethylation. Recombinant CYP2C9 microsomes of distinguished genotypes were used to characterize the corresponding enzyme activity toward carvedilol. 2-100 µM carvedilol was incubated for 30 min at 37 °C. The products were detected using high-performance liquid chromatography. CYP2C9 plays a certain role in carvedilol metabolism. Compared with wild-type CYP2C9*1, the intrinsic clearance (V max/K m) values of all variants toward carvedilol O-desmethylation were significantly altered. The variants exhibited significantly decreased values (from 30 to 99.8 %) due to increased K m and/or decreased V max values. We conclude that recombinant system could be used to investigate the enzymes involved in drug metabolism and these findings complement the database where CYP2C9 polymorphism interacts with biotransformation of exogenous substances like drugs and toxins.


Assuntos
Povo Asiático/genética , Carbazóis/metabolismo , Citocromo P-450 CYP2C9/genética , Citocromo P-450 CYP2C9/metabolismo , Polimorfismo Genético/genética , Propanolaminas/metabolismo , Carbazóis/farmacologia , Carvedilol , Relação Dose-Resposta a Droga , Humanos , Metilação , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Propanolaminas/farmacologia
11.
Sci Total Environ ; 514: 409-17, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25681777

RESUMO

To evaluate the impacts of anthropogenic events on the rapid urbanized environment, the levels of legacy organochlorine pesticides (OCPs) and current-use insecticides (CUPs), i.e., dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), pyrethroids and organophosphates in soil of the Pearl River Delta (PRD) and surrounding areas were examined. Spatial concentration distributions of legacy OCPs and CUPs shared similar patterns, with higher concentrations occurred in the central PRD with more urbanization level than that in the PRD's surrounding areas. Furthermore, relatively higher concentrations of OCPs and CUPs were found in the residency land than in other land-use types, which may be attributed to land-use change under rapid urbanization. Moderate correlations between gross domestic production or population density and insecticide levels in fifteen administrative districts indicated that insecticide spatial distributions may be driven by economic prosperity. The soil-air diffusive exchanges of DDTs and HCHs demonstrated that soil was a sink of atmospheric o,p'-DDE, o,p'-DDD, p,p'-DDD and o,p'-DDT, and was a secondary source of HCHs and p,p'-DDT to atmosphere. The soil inventories of DDTs and HCHs (100 ± 134 and 83 ± 70 tons) were expected to decrease to half of their current values after 18 and 13 years, respectively, whereas the amounts of pyrethroids and organophosphates (39 and 6.2 tons) in soil were estimated to decrease after 4 and 2 years and then increase to 87 and 1.0 tons after 100 years. In this scenario, local residents in the PRD and surrounding areas will expose to the high health risk for pyrethroids by 2109. Strict ban on the use of technical DDTs and HCHs and proper training of famers to use insecticides may be the most effective ways to alleviate the health effect of soil contamination.


Assuntos
Monitoramento Ambiental , Inseticidas/análise , Poluentes do Solo/análise , China , Solo/química , Urbanização/tendências
12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(11): 3100-4, 2015 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-26978917

RESUMO

A fluoroimmunoassay based on quantum dots (QDs) and a lateral flow immunoassay system based on the magnetic beads (MB) were constructed to detect ractopamine (RAG) in urine samples. The monoclonal antibody (Ab1) against RAC was conjugated with QDs or MB as detector reagent, respectively. They apply a competitive format using an immobilized RAC conjugate and free RAC present in samples. That is to say, the concentration of RAC in the sample was negative related to the fluorescense intensity of QDs or the color density of MB. Results showed that the limit of detection (LOD) of fluorescence immunoassay method is 1 ng · mL⁻¹ and analysis time is 4 h, while the visual LOD was 10 ng · mL⁻¹ and analysis time was 15 min in magnetic lateral flow immunoassay system (MFLIS). Taken into consideration of the advantages and disadvantages of the two methods, it was suitable for the trace detection of RAC using fluoroimmunoassay while it was appropriate for point-of-care tesing of RAC by MFLIS.


Assuntos
Fluorimunoensaio , Imunoensaio , Fenetilaminas/urina , Anticorpos Monoclonais/química , Humanos
13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(11): 3105-10, 2015 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-26978918

RESUMO

Fluoroimmunoassay based on quantum dots (QDs) and magnetic relaxation switch (MRS) immunoassay based on superparamagnetic nanoparticles (SMN) were constructed to detect Salmonella enterica (S. enterica) in water samples. In fluoroimmunoassay, magnetic beads was conjugated with S. enterica capture antibody (MB-Ab2) to enrich S. enterica from sample solution, then the QDs was conjugated with the S. enterica detection antibody (QDs-Ab1) to detect S. enterica based on sandwich immunoassay format. And the fluorescence intensity is positive related to the bacteria concentration of the sample. Results showed that the limit of detection (LOD) of this method was 102 cfu · mL⁻¹ and analysis time was 2 h. In MRS assay, magnetic nanoparticle-antibody conjugate (MN-Ab1) can switch their dispersed and aggregated state in the presence of the target. This state of change can modulate the spin-spin relaxation time (T2) of the neighboring water molecule. The change in T2(ΔT2) positively correlates with the amount of the target in the sample. Thus, AT can be used as a detection signal in MRS immunosensors. Results showed that LOD of MRS sensor for S. enterica was 10³ cfu · mL⁻¹ and analysis time was 0.5 h. Two methods were compared in terms of advantages and disadvantages in detecting S. enterica.


Assuntos
Fluorimunoensaio , Salmonella enterica/isolamento & purificação , Água/análise , Fenômenos Magnéticos , Nanopartículas de Magnetita , Pontos Quânticos , Microbiologia da Água
14.
Environ Sci Pollut Res Int ; 22(3): 1635-43, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25096494

RESUMO

Available literature data on five typical groups of emerging contaminants (EMCs), i.e., chlorinated paraffins (CPs), dechlorane plus and related compounds (DPs), hexabromocyclododecanes (HBCDs), phthalate esters, and pyrethroids, accumulated between 2003 and 2013 were assimilated. Research efforts were categorized by environmental compartments and countries, so that global trends of research on EMCs and data gaps can be identified. The number of articles on the target EMCs ranged from 126 to 1,379 between 2003 and 2013. The numbers of articles on CPs, DPs, HBCDs, and pyrethroids largely followed the sequence of biota > sediment ≥ air > water ≥ soil > human tissue, whereas the sequence for phthalate esters was water > sediment > soil > human tissue ≥ biota ≥ air. Comprehensive studies on the target EMCs in biological samples and human tissues have been conducted worldwide. However, investigations into the occurrence of the target EMCs in soil of background areas and water are still scarce. Finally, developed and moderately developed countries, such as the USA, China, Canada, Japan, and Germany, were the main contributors to the global research efforts on EMCs, suggesting that economic prosperity may be one of the main factors propelling scientific research on EMCs.


Assuntos
Conservação dos Recursos Naturais/métodos , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Humanos , Pesquisa/economia
15.
Nat Commun ; 5: 5315, 2014 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-25350882

RESUMO

The jujube (Ziziphus jujuba Mill.), a member of family Rhamnaceae, is a major dry fruit and a traditional herbal medicine for more than one billion people. Here we present a high-quality sequence for the complex jujube genome, the first genome sequence of Rhamnaceae, using an integrated strategy. The final assembly spans 437.65 Mb (98.6% of the estimated) with 321.45 Mb anchored to the 12 pseudo-chromosomes and contains 32,808 genes. The jujube genome has undergone frequent inter-chromosome fusions and segmental duplications, but no recent whole-genome duplication. Further analyses of the jujube-specific genes and transcriptome data from 15 tissues reveal the molecular mechanisms underlying some specific properties of the jujube. Its high vitamin C content can be attributed to a unique high level expression of genes involved in both biosynthesis and regeneration. Our study provides insights into jujube-specific biology and valuable genomic resources for the improvement of Rhamnaceae plants and other fruit trees.


Assuntos
Frutas/genética , Genoma de Planta/genética , Árvores/genética , Ziziphus/genética , Adaptação Fisiológica/genética , Ácido Ascórbico/metabolismo , Metabolismo dos Carboidratos/genética , Cromossomos de Plantas/genética , Duplicação Gênica/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Anotação de Sequência Molecular , Dados de Sequência Molecular , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Alinhamento de Sequência , Análise de Sequência de DNA , Análise de Sequência de RNA , Especificidade da Espécie , Estresse Fisiológico/genética , Sintenia/genética
16.
Sci Total Environ ; 473-474: 676-84, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24412913

RESUMO

The occurrence of polycyclic aromatic hydrocarbons (PAHs) in soil of the Pearl River Delta (PRD) and surrounding areas was examined on a basis of six land-use types and four geographic regions, from which the impacts of anthropogenic events on the terrestrial environment were evaluated. No significant difference in the concentrations of Σ28PAH and Σ15PAH (sums of 28 and 15 PAHs, respectively) was found among the land-use types of industry, landfill and residency. On the other hand, higher soil PAH concentrations occurred in the central PRD characterized by dense population and high urbanization level, compared to other geographic regions. Source diagnostics implicated the combustions of coal and refined petroleum as the major input sources of anthropogenic PAHs. Furthermore, low molecular weight PAHs tended to volatilize from soil to air while the opposite was prevailing for high molecular weight PAHs. The mean annual diffusive flux of Σ15PAH (852 µg m(-2)yr(-1)) from the soil to the atmosphere in the central PRD was greater than those in the PRD's periphery (195 µg m(-2)yr(-1)), West region (322 µg m(-2)yr(-1)) and East region (84.9 µg m(-2)yr(-1)), suggesting that the central PRD may have become a secondary source of PAHs to the surrounding areas. Finally, ecological risk assessment based on the classification from Maliszewska-Kordybach showed that 3.5% of soil within the central PRD was heavily contaminated by PAHs and 5.2 million residents may be subjected to high health risk.


Assuntos
Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes do Solo/análise , Solo/química , Medição de Risco , Urbanização
17.
Huan Jing Ke Xue ; 35(10): 3821-9, 2014 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-25693389

RESUMO

To examine the distribution patterns of organic contaminants in rapidly urbanizing regions, the levels and spatial distributions of 19 overlooked insecticides, i. e., phenyl-pyrazole class (fipronil), chlordane, endosulfan, nonachlor, hexachlorobenzene, heptachlor, dieldrin, aldrin, endrin, methoxychlor and their metabolites, were examined in 229 soil samples collected from the Pearl River Delta (PRD) and surrounding areas. The results indicated that higher insecticide levels distributed in the central PRD, while lower levels congested in the surrounding areas. The similar spatial patterns between the levels of insecticides and economic prosperity or population density demonstrated that social-economic factors may have dictated the spatial patterns of insecticides. In addition, the changing of land-use types during urbanization processes, e.g., historical plowlands have been converted into residential landscapes, resulted in high concentrations of banned insecticides in metropolis of the central PRD. Source diagnostics indicated that new inputs of technical chlordane products existed in the PRD and surrounding areas. Fipronil was degraded into fipronil sulfone and fipronil sulfide in most soil samples because of its low half-life in soil. Finally, a risk assessment of 19 insecticides in soil for human health suggested that six samples collected from the major administrative districts with dense population had potential cancer or non-cancer risk to human health. Therefore, these overlooked insecticides should be concerned in future environmental research.


Assuntos
Resíduos de Praguicidas/análise , Poluentes do Solo/análise , Solo/química , Urbanização , China , Meia-Vida , Medição de Risco , Análise Espacial
18.
Sci Total Environ ; 463-464: 1093-110, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-23245873

RESUMO

Rapid economic growth in South China (including Guangdong Province, Hong Kong, and Macau), particularly within the Pearl River Delta region, has resulted in severe pollution of the natural eco-environment in the last three decades. Large amounts of monitoring data on organic pollution in the Pearl River Delta have been accumulated, which allows us to conduct a fairly comprehensive assessment of the state of the Pearl River Delta and elucidate spatial and temporal patterns of pollution on a regional scale. Of various causes for environmental deterioration, negative impact from persistent organic pollutants (POPs) is a global concern. This review examines the current levels and distribution patterns of several POPs, namely DDT (and its metabolites DDD and DDE), hexachlorocyclohexanes, and polybrominated diphenyl ethers, in various environmental compartments of South China. The general information on environmental occurrence, regional behaviors, ecological effects, and human exposure of these POPs in this region are reviewed.


Assuntos
Exposição Ambiental/análise , Rios/química , Poluentes Químicos da Água/análise , China , DDT/efeitos adversos , DDT/análise , Exposição Ambiental/efeitos adversos , Éteres Difenil Halogenados/efeitos adversos , Éteres Difenil Halogenados/análise , Hexaclorocicloexano/efeitos adversos , Hexaclorocicloexano/análise , Humanos , Poluentes Químicos da Água/efeitos adversos
19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 28(4): 887-90, 2008 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-18619322

RESUMO

The present article studied the interaction between intramolecular charge transfer fluorescence probe-1-keto-2-(p-dimethylaminobenzal)-tetrohydronaphthalene (KDTN) and bovine serum albumins (BSA). With the concentration of KDTN increasing, the fluorescence of BSA rapidly quenched and the fluorescence peak gradually blue-shifted. The result indicated that they were bound mainly by hydrophobic interaction. The binding sites is 0.94 (3 degrees C) and the equilibrium constant K is 3.27 x 10(4) L x mol(-1). Temperature increment is advantageous to the combination. It is a single static quenching process that the fluorescence of BSA quenches, which is induced by the combination of KDTN and BSA. Further study showed that different substances had different effects on the combination of KDTN and BSA.


Assuntos
Naftalenos/análise , Soroalbumina Bovina/análise , Espectrometria de Fluorescência/métodos , Animais , Bovinos , Estrutura Molecular , Naftalenos/química , Soroalbumina Bovina/química , Temperatura
20.
Guang Pu Xue Yu Guang Pu Fen Xi ; 26(1): 125-9, 2006 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-16827360

RESUMO

The interaction of tetrabramofluorescein (TBF) and DNA was studied by the fluorescence and SS-RTP. The effect of the ion strength and ethanol on the fluorescence spectra of TBF in the presence of DNA and absence of DNA was investigated. In addition, the effect of pH on the SS-RTP spectra of TBF was also examined. The quenched constant was 719.74 and 880.22 in the absence and presence of DNA respectively. Finally, the interaction mode between TBF and DNA was discussed from the fluorescence quenched and phosphorescence polarized experiments.


Assuntos
DNA/química , Amarelo de Eosina-(YS)/química , Animais , Bovinos , Cinética , Estrutura Molecular , Espectrometria de Fluorescência
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