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1.
J Org Chem ; 85(7): 4973-4980, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32118426

RESUMO

Four unusual polyketides possessing three unambiguous chemical architectures were discovered from the fermentation of Penicillium canescens assisted by the one strain-many compounds (OSMAC) strategy and MS2-based molecular networking. Penicanone (1) is the first naturally occurring polyketide characterized by a 6/6/8 tricyclic carbon skeleton incorporating an unusual bicyclo[5.3.1]hendecane core. Penicanesones A-C (2-4) are aromatic polyketide dimers simultaneously featuring inconsistent 6/5/5/6 and 6/6/5/6 heterotetracyclic ring cores. Their plausible biosynthetic pathways and screening of biological activity were described here.

2.
Phytochemistry ; 164: 184-191, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31158603

RESUMO

Eleven highly oxygenated meroterpenoids, named terreustoxins A-K, along with five known analogues, were isolated from the Antarctic fungus Aspergillus terreus. The structures and absolute configurations of these undescribed compounds were characterized by NMR spectroscopy, single-crystal X-ray crystallography, and ECD experiments. Terreustoxins A-D are the first examples of meroterpenoids with two ortho-hydroxy groups at C-6 and C-7 in the terretonins family. Terreustoxin C and terretonin inhibited the proliferation of Con A-induced murine T cells at the concentration of 10 µM.


Assuntos
Aspergillus/química , Oxigênio/farmacologia , Terpenos/farmacologia , Animais , Aspergillus/metabolismo , Proliferação de Células/efeitos dos fármacos , Concanavalina A , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Camundongos , Modelos Moleculares , Conformação Molecular , Oxigênio/química , Oxigênio/metabolismo , Estereoisomerismo , Relação Estrutura-Atividade , Linfócitos T/efeitos dos fármacos , Terpenos/química , Terpenos/metabolismo
3.
Org Biomol Chem ; 17(22): 5526-5532, 2019 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-31041978

RESUMO

Marine-derived fungi have been regarded as an under-explored and promising reservoir of structurally novel and bioactive natural products. In this study, five new γ-pyrone-containing polyketides, fusaresters A-E (1-5), were isolated and identified from the culture extracts of a marine-derived fungus Fusarium sp. Hungcl. The structures of compounds 1-5 were elucidated on the basis of their HRESIMS and NMR spectroscopic data as well as 13C NMR calculation and electronic circular dichroism (ECD) analyses. Remarkably, the structure of fusariumin D was revised to (9S*,11S*)-3. All these isolates were tested for the cytotoxicity against seven human cancer cell lines, including SW480, HL-60, A549, MCF-7, HepG2, HeLa and SMMC-7721, and the inhibitory activity against protein tyrosine phosphatase 1B (PTP1B). The results revealed that only compound 2 showed a weak inhibition rate of 56% at 40 µM.


Assuntos
Cumarínicos/química , Fusarium/química , Policetídeos/isolamento & purificação , Pironas/isolamento & purificação , Estrutura Molecular , Policetídeos/química , Pironas/química
4.
Fish Shellfish Immunol ; 89: 393-402, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30980915

RESUMO

In order to investigate the dynamic distribution of antigen in different tissues post vaccination, an absolute real-time quantitative PCR was employed to detect the amount of antigen in flounder (Paralichthys olivaceus) post intraperitoneal (i.p.) injection with three concentrations (107, 108, 109 CFU ml-1) of formalin-inactivated Edwardsiella tarda bacterin. The results showed that the amount of uptaken antigen quickly increased and then decreased in different tissues. The peak occurred first in the spleen and head kidney at 6-9 h after injection, and in the liver and blood at 9-15 h, then in the gill, intestine and skin at 15-24 h, finally in the muscle at 24-36 h. The amount of antigen was highest in the spleen and head kidney, followed by the blood, liver and gill, and lowest in the intestine, skin and muscle. Among the three concentration groups, the amount of antigen increased with the increasing concentration of the vaccine in the blood, liver, gill, intestine, skin and muscle, except for the spleen and head kidney, in which more antigens were found in the 108 CFU ml-1 group than that in 109 CFU ml-1 group. Moreover, IIFA and western blotting was performed to examine the tissue distribution of antigen at 9 h after vaccination with 108 CFU ml-1 formalin-inactivated E. tarda. The bacteria were mainly observed in the spleen and head kidney, then the liver, gill and blood, and least in the intestine, skin and muscle, which was roughly in accordance with the results of absolute qPCR. Furthermore, the expressions of CD4-1, MHC IIα, CD8α and MHC Iα in different tissues were detected by RT-qPCR, and the expression levels of these genes were highest in the spleen and head kidney, then in the blood, gill, liver, and lowest in the intestine, skin and muscle. All these results provided useful information for dynamic transportation of antigen uptake post vaccination, and also deepened the understanding of immune response to the injection vaccination.


Assuntos
Vacinas Bacterianas/administração & dosagem , Edwardsiella tarda/fisiologia , Infecções por Enterobacteriaceae/veterinária , Doenças dos Peixes/prevenção & controle , Linguados , Vacinação/veterinária , Animais , Edwardsiella tarda/efeitos dos fármacos , Infecções por Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/prevenção & controle , Doenças dos Peixes/imunologia , Formaldeído/farmacologia , Vacinas de Produtos Inativados/administração & dosagem
5.
Bioorg Chem ; 86: 176-182, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30711700

RESUMO

Dibrefeldins A and B (1 and 2), two unexpected brefeldin A (BFA) dimers, as well as brefeldin F (3), brefeldin G (4), and 14-hydroxy-BFA (5), three new BFA derivatives, together with three new naturally occurring BFA derivatives (6-8) and four known analogues (9-12), were isolated from the fungus Penicillium janthinellum. Dibrefeldins A and B (1 and 2) represent the first examples of BFA dimers formed by an esterification between two BFA monomer units. Brefeldin F (3) has an α,ß-unsaturated γ-lactone ring, and this moiety was first discovered in naturally occurring BFA derivatives. The structures and relative/absolute configurations of these derivatives were elucidated by extensive spectroscopic methods, 13C NMR calculations, and single-crystal X-ray diffraction. Compounds 1, 2, 8, and 9 showed excellent cytotoxic activities against six cancer cell lines with IC50 values ranging from 0.01 to 4.45 µM.


Assuntos
Antineoplásicos/farmacologia , Brefeldina A/farmacologia , Penicillium/química , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Brefeldina A/química , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Teoria da Densidade Funcional , Dimerização , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Relação Estrutura-Atividade
6.
J Org Chem ; 84(3): 1534-1541, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30608689

RESUMO

Six new 3,5-demethylorsellinic acid-based meroterpenoids, emeridones A-F (1-6), and eight known analogues (7-14) were isolated from Emericella sp. TJ29. Their structures and absolute configurations were elucidated by comprehensive spectroscopic analyses, single-crystal X-ray diffraction experiments, and electronic circular dichroism calculations. Emeridone A (1) represents the first meroterpenoid featuring a unique rigid 6/6/5/6 tetracyclic carbon ring system with two additional lactone rings. Emeridones B and C (2 and 3) possess a 2,6-dioxabicyclo[2.2.1]heptane and a spiro[bicyclo[3.2.2]nonane-2,1'-cyclohexane] moiety, respectively, and both functionalities were found for the second time in meroterpenoids. These new compounds were evaluated for their cytotoxic activities against five human cancer cells, and compounds 2, 4, and 6 exhibited moderate cytotoxic activities, with IC50 values ranging from 8.19 to 18.80 µM.

7.
Nutr Res ; 60: 1-12, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30527253

RESUMO

Oxidative stress (OS) is associated with aging and multiple diseases, yet the effects of curcumin in humans are not definite. We undertook a meta-analysis of the effects of curcumin on OS biomarkers. In January 2018, we searched PubMed, Books@Ovid, Journals@Ovid, EMBASE, MEDLINE(R), and Web of Science to identify randomized controlled trials conducted ≥4 weeks and investigating the effects of curcumin on OS biomarkers, including glutathione peroxidase (GPX) activity in red blood cells (RBC), serum malondialdehyde (MDA) concentrations, and superoxide dismutase (SOD) activity. The standardized mean difference (SMD) with a 95% confidence interval (CI) was used to present the results. The meta-analysis included eight clinical studies (626 patients). There was a significant reduction in circulating MDA concentrations (SMD = -0.769, 95% CI: -1.059 to -0.478) and a significant increase in SOD activity (SMD = 1.084, 95% CI: 0.487 to 1.680) following curcumin supplementation. There was no change in the GPX activity in RBC. There was no significant association between the MDA-lowering effect of curcumin with underlying diseases or treatment duration. However, curcumin showed the MDA-lowering effect at curcuminoids doses ≥600 mg/d (P < .0001). This effect was greater when combined with piperine than curcuminoids alone (SMD = -1.085, 95% CI: -1.357 to -0.813; SMD = -0.850, 95% CI: -1.158 to -0.542). Curcumin may play an anti-oxidative role by reducing circulating MDA concentrations and increasing SOD activity. Further research of curcumin in different populations with multiple biomarkers of redox status is required.


Assuntos
Antioxidantes/farmacologia , Curcuma/química , Curcumina/farmacologia , Suplementos Nutricionais , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Antioxidantes/metabolismo , Humanos , Malondialdeído/sangue , Ensaios Clínicos Controlados Aleatórios como Assunto , Superóxido Dismutase/metabolismo
8.
J Nat Prod ; 81(7): 1578-1587, 2018 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-29969028

RESUMO

The cocultivation of Aspergillus flavipes and Chaetomium globosum, rich sources of cytochalasans, on solid rice medium, resulted in the production of 13 new, highly oxygenated cytochalasans, aspochalasinols A-D (1-4) and oxichaetoglobosins A-I (5-13), as well as seven known compounds (14-20). Of these compounds, 13 is a novel cytochalasan with an unexpected 2-norindole group. The isolated compounds were characterized by NMR spectroscopy, single-crystal X-ray crystallography, and ECD experiments. Compounds 1-4 represent the first examples of Asp-type cytochalasans with C-12 hydroxy groups, which may be a result of the coculture, as hydroxylated Me-12 groups are frequently found in Chae-type cytochalasans from C. globosum. In addition, 5-10 are unusual cytochalasans with an oxygenated C-10. Interestingly, 13 is the first example of a naturally occurring cytochalasan possessing a uniquely degraded indole ring that is derived from chaetoglobosin W, with 11 and 12 both serving as its biosynthetic intermediates. In the coculture of A. flavipes and C. globosum, most of these cytochalasans are more functionalized than normal cytochalasans, and the underlying causes may attract substantial attention from synthetic biologists. The cytotoxicities against five human cancer cell lines (SW480, HL-60, A549, MCF-7, and SMMC-7721) and the immunomodulatory activities of these new compounds were evaluated in vitro.


Assuntos
Aspergillus/metabolismo , Chaetomium/metabolismo , Citocalasinas/biossíntese , Animais , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Cromatografia Líquida de Alta Pressão , Técnicas de Cocultura , Cristalografia por Raios X , Citocalasinas/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Células HL-60 , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Camundongos , Estrutura Molecular
9.
J Ethnopharmacol ; 220: 9-15, 2018 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-29567277

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Castanea mollissima shell (CMS) has been used for wound healing in China as traditional medicine. The shell is directly applied on the wounded skin as fine powder or as water maceration. AIM OF THE STUDY: To investigate the wound healing activity of CMS and the potential mechanism of anti-inflammatory activity. MATERIALS AND METHODS: The effects of ethanol extract of CMS (ECMS) on nitricoxide (NO), tumor necrosis factor (TNF)-α and interleukin (IL)- 6 productions in lipopolysaccharide (LPS)-treated RAW 264.7 cells were explored by enzyme linked immunosorbent assay (ELISA) in vitro. To study wound healing properties of ECMS in vivo, excision and incision wound models were performed on rats. Inflammatory cytokines from wound biopsies such as NO, TNF-α and IL-6 production were tested by ELISA. mRNA levels of iNOS, cyclooxygenase (COX) -2 and TNF-α were detected by real-time Polymerase Chain Reaction (PCR), and protein levels of IL-1ß and Heme Oxygenase (HO) -1 were analyzed by Western blotting. RESULTS: ECMS potently inhibited LPS-induced production of IL-6, NO and TNF-α in RAW 264.7 cells. The presence of quercetin, kaempferol, ursolic acid and gallic acid in ECMS might be responsible for its anti-inflammatory activity. 3% and 5% w/w ECMS significantly accelerated the wound healing process in both wound models, evidenced by the faster rate of wound contraction, epithelialization, increased hydroxyproline content, high tensile strength, decreased level of inflammatory markers compared to the control group. Histopathological studies also revealed the amelioration of wound healing by re-epithelialization, collagenation and vascularization of wounded skin sample in ECMS treated groups. CONCLUSION: The experimental data revealed that CMS had ability to prevent exaggerated inflammation and accelerates wound epithelialization and might be beneficial for healing dermal wounds.


Assuntos
Anti-Inflamatórios/farmacologia , Fagaceae/química , Extratos Vegetais/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Anti-Inflamatórios/isolamento & purificação , Citocinas/metabolismo , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Inflamação/tratamento farmacológico , Inflamação/patologia , Lipopolissacarídeos , Masculino , Medicina Tradicional Chinesa , Camundongos , Células RAW 264.7 , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real
10.
Nutr J ; 16(1): 68, 2017 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-29020971

RESUMO

BACKGROUND: Dyslipidemia is an important and common cardiovascular risk factor in the general population. The lipid-lowering effects of turmeric and curcumin are unconfirmed. We performed a meta-analysis to assess the efficacy and safety of turmeric and curcumin in lowering blood lipids in patients at risk of cardiovascular disease (CVD). METHODS: A comprehensive literature search was conducted on PubMed, Embase, Ovid, Medline and Cochrane Library databases to identify randomized controlled trials (published as of November 2016) that assessed the effect of turmeric and curcumin on blood lipid levels including total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG). Pooled standardized mean difference (SMD) with 95% confidence interval (CI) was used to assess the effect. RESULTS: The analysis included 7 eligible studies (649 patients). Turmeric and curcumin significantly reduced serum LDL-C (SMD = -0.340, 95% confidence interval [CI]: -0.530 to -0.150, P < 0.0001) and TG (SMD = -0.214, 95% CI: -0.369 to -0.059, P = 0.007) levels as compared to those in the control group. These may be effective in lowering serum TC levels in patients with metabolic syndrome (MetS, SMD = -0.934, 95% CI: -1.289 to -0.579, P < 0.0001), and turmeric extract could possibly have a greater effect on reducing serum TC levels (SMD = -0.584, 95% CI: -0.980 to -0.188, P = 0.004); however, the efficacy is yet to be confirmed. Serum HDL-C levels were not obviously improved. Turmeric and curcumin appeared safe, and no serious adverse events were reported in any of the included studies. CONCLUSIONS: Turmeric and curcumin may protect patients at risk of CVD through improving serum lipid levels. Curcumin may be used as a well-tolerated dietary adjunct to conventional drugs. Further research is required to resolve uncertainties related to dosage form, dose and medication frequency of curcumin.


Assuntos
HDL-Colesterol/sangue , LDL-Colesterol/sangue , Curcuma/química , Curcumina/farmacologia , Fitoterapia , Triglicerídeos/sangue , Doenças Cardiovasculares/sangue , Humanos , Preparações de Plantas/farmacologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco
11.
Int J Oncol ; 2017 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-28350119

RESUMO

Hepatocellular carcinoma (HCC) is one of most common malignant cancers and is the second leading cause of cancer related deaths. The prognosis and survival of patients are closely related to the degree of tumor metastasis. The mechanism of HCC metastasis is still unclear. In the present study, we investigated the molecular mechanism of C-reaction protein in promoting migration and invasion of hepatocellular carcinoma cells in vitro. We estimated that CRP is overexpressed in liver cancer tissues and that it promotes invasion and metastasis of HCC in vitro. In the present study, we employed iTRAQ-based mass spectrometry to analyze the HepG2 secretory proteins of CRP siRNA-treated cells and negative control siRNA-treated cells. We identified 109 differentially expressed proteins after silencing CRP, of which 45 were upregulated and 64 were downregulated. Some of the differentially expressed proteins were confirmed by western blot analysis and real-time quantitative PCR. Furthermore, we found that knockdown of CRP substantially abrogates HIF-1α expression levels, the luciferase activity of HIF-1α and ERK and Akt phosphorylation in HepG2 cells. The present study provides a novel mechanism by which CRP promotes the proliferation, migration, invasion and metastasis of hepatocellular carcinoma cells. Inhibition of CRP suppressed migration, invasion and healing of hepatoma carcinoma cells by decreasing HIF-1α activity and CTSD.

12.
Int J Oncol ; 50(3): 883-892, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28197637

RESUMO

Hepatocellular carcinoma is the second most common cause of cancer-related deaths worldwide. Due to a high propensity to metastasize, active angiogenesis and rapid proliferation, recurrence and poor prognosis are major obstacles for treatment and cure of this disease. However, the detailed mechanisms of how fatty acid synthase (FASN) promotes migration, invasion and healing in tumor cells remain unclear. In the present study, the previous results that FASN was expressed higher in cancer samples than in non-cancerous samples, and influenced migration, invasion of hepatoma carcinoma cells, were verified by immunohistochemistry, tissue microarrays, Transwell assay and wound healing assay. The secretory proteins of hepatocellular carcinoma cells with or without FASN knockdown were analyzed using the isobaric tags for relative and absolute quantitation (iTRAQ) method to identify differentially expressed proteins (DEPs). The DEPs were verified by RT-PCR and western blot analysis, and were consistent with the iTRAQ results. Inhibition of FASN can decrease the levels of IGFBP1, and the expression, activity, and ubiquitination of HIF-1α. Inhibition of FASN can suppress migration, invasion and healing of hepatoma carcinoma cells by decreasing HIF-1α, and IGFBP1.


Assuntos
Carcinoma Hepatocelular/patologia , Movimento Celular/genética , Ácido Graxo Sintase Tipo I/antagonistas & inibidores , Ácido Graxo Sintase Tipo I/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Neoplasias Hepáticas/patologia , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Invasividade Neoplásica/genética , Interferência de RNA , RNA Interferente Pequeno/genética
13.
Gastroenterol Res Pract ; 2016: 7214020, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26880896

RESUMO

Background/Aims. It remains unclear whether tenofovir disoproxil fumarate- (TDF-) based combination therapy produces better outcomes than TDF monotherapy in chronic hepatitis B (CHB) patients. The aim of this study was to compare the efficacy of the two regimens by performing a meta-analysis. Methods. A comprehensive literature search was performed on the comparison of TDF-based combination therapy and monotherapy for CHB patients in the PubMed, Embase, Web of Science, and the Cochrane Libraries. Both dichotomous and continuous variables were extracted and pooled outcomes were expressed as risk ratio (RR) or standard mean difference (SMD). Results. Nine eligible studies (1089 subjects in total) were included in our analysis. The proportion of patients with undetectable HBV DNA at 24, 48, and 96 weeks were similar between the two comparable groups (62.5% versus 70.9%, P = 0.086; 78.1% versus 83.7%, P = 0.118; 86.4% versus 87.9%, P = 0.626, resp.). HBV DNA reduction, rates of ALT normalization, hepatitis B e antigen (HBeAg) loss, and HBeAg seroconversion were also similar between the two groups. Conclusions. On the current data, TDF-based combination therapy seemed to be no better than those achieved by monotherapy. Further studies are needed to verify this comparison.

14.
Nutr J ; 14: 67, 2015 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-26155840

RESUMO

Most hepatocellular carcinoma (HCC) patients have complications, including cirrhosis and malnutrition. The efficacy of dietary supplementation with oral branched-chain amino acids (BCAAs) in HCC patients undergoing interventions has not been confirmed. Relevant publications on the efficacy and safety of oral BCAA supplementation for HCC patients undergoing anti-HCC interventions through September, 2014 were searched for identification in the PubMed, Embase, Web of Science, and the Cochrane Library databases. The pooled risk ratio (RR) and standardized mean difference (SMD) were used to assess the supplementation effects. A total of 11 eligible studies (974 patients in total) were evaluated and included in our analysis. Oral BCAA supplementation helped to maintain liver reserve with higher serum albumin (SMD = 0.234, 95% CI: 0.033-0.435, P = 0.022), and lower rates of ascites (RR = 0.545, 95% CI: 0.316-0.938, P = 0.029) and edema (RR = 0.494, 95% CI: 0.257-0.952, P = 0.035) than in the control group. BCAA supplementation seemed to be effective in improving mortality, especially in Child-Pugh class B patients, but the efficacy was not confirmed. Apparent effects were not found in improving HCC recurrence, total bilirubin, ALT, or AST. BCAA supplementation was relatively safe without serious adverse events. BCAA supplementation may be clinically applied in improving liver functional reserve for HCC patients and further improving the quality of life.


Assuntos
Aminoácidos de Cadeia Ramificada/administração & dosagem , Carcinoma Hepatocelular/tratamento farmacológico , Suplementos Nutricionais , Neoplasias Hepáticas/tratamento farmacológico , Aminoácidos de Cadeia Ramificada/efeitos adversos , Carcinoma Hepatocelular/mortalidade , Bases de Dados Factuais , Avaliação Pré-Clínica de Medicamentos , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas/mortalidade , Ensaios Clínicos Controlados Aleatórios como Assunto
15.
J Am Chem Soc ; 134(38): 15720-3, 2012 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-22963520

RESUMO

TiO(2) nanotube arrays (TNTAs) sensitized by palladium quantum dots (Pd QDs) exhibit highly efficient photoelectrocatalytic hydrogen generation. Vertically oriented TNTAs were prepared by a three-step electrochemical anodization. Subsequently, Pd QDs with uniform size and narrow size distribution were formed on TiO(2) nanotubes by a modified hydrothermal reaction (i.e., yielding nanocomposites of Pd QDs deposited on TNTAs, Pd@TNTAs). By exploiting Pd@TNTA nanocomposites as both photoanode and cathode, a substantially increased photon-to-current conversion efficiency of nearly 100% at λ = 330 nm and a greatly promoted photocatalytic hydrogen production rate of 592 µmol·h(-1)·cm(-2) under 320 mW·cm(-2) irradiation were achieved. The synergy between nanotubular structures of TiO(2) and uniformly dispersed Pd QDs on TiO(2) facilitated the charge transfer of photoinduced electrons from TiO(2) nanotubes to Pd QDs and the high activity of Pd QDs catalytic center, thereby leading to high-efficiency photoelectrocatalytic hydrogen generation.

16.
Chem Commun (Camb) ; 47(9): 2598-600, 2011 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-21170455

RESUMO

A novel nanocomposite TiO(2) film consisting of a bamboo leaf-like nano TiO(2) layer on a nanotubular TiO(2) arrays surface is synthesized by electrochemical anodization with wet chemical pretreatment; it shows almost three times higher activity as compared to that of nanotubular TiO(2) arrays alone.

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