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1.
J Nanosci Nanotechnol ; 20(2): 668-672, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383061

RESUMO

Currently, optical probes with near-infrared (NIR) fluorescence are of great interest in chemical biology. In the present study, we designed and synthesized a novel NIR fluorescent probe, IR789. IR789 has high selectivity and sensitivity for living cells imaging. The stronger excitation and emission characteristics suggested its dominant optical properties over ICG. IR789 also showed a high affinity and inconspicuous cytotoxicity at the cellular level. The results of fluorescent image in living A549 cells (human lung adenocarcinoma epithelial cell line) further demonstrated its potential applications for biomedical diagnosis in biological systems utilization of nanotechnology.

2.
Int J Nanomedicine ; 14: 5201-5213, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31371956

RESUMO

Background: SN38 (7-ethyl-10-hydroxy camptothecin), as a potent metabolite of irinotecan, is highly efficacious in cancer treatment. However, the clinical utility of SN38 has been greatly limited due to its undesirable properties, such as poor solubility and low stability. Materials and methods: In order to overcome these weaknesses, moeixitecan, a lipophilic SN38 prodrug containing a SN-38, a trolox, a succinic acid linker, and a hexadecanol chain, was loaded into liposomal nanoparticles by ethanol injection method. Results: Experiments showed that the moeixitecan-loaded liposomal nanoparticles (MLP) with a diameter of 105.10±1.49 nm have a satisfactory drug loading rate (90.54±0.41%), high solubility and stability, and showed sustained release of SN38. Notably, MLP exhibited better antitumor activity against human colon adenocarcinoma cells than irinotecan, a FDA-approved drug for the treatment of advanced colorectal cancer. Furthermore, xenograft model results showed that MLP outperformed irinotecan in terms of pharmacokinetics, in vivo therapeutic efficacy and safety. Finally, we used molecular dynamic simulations to explore the association between the structure of MLP and the physical and functional properties of MLP, moeixitecan molecules in MLP folded themselves inside the hydrocarbon chain of the lipid bilayer, which led an increased acyl chain order of the lipid bilayer, and therefore enhanced the lactone ring stability protecting it from hydrolysis. Conclusion: Our MLP constructing strategy by liposome engineering technology may serve a promising universal approach for the effective and safe delivery of lipophilic prodrug.

3.
Front Microbiol ; 9: 1087, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29887849

RESUMO

Bacterial endophytes with the capacity to degrade petroleum hydrocarbons and promote plant growth may facilitate phytoremediation for the removal of petroleum hydrocarbons from contaminated soils. A hydrocarbon-degrading, biosurfactant-producing, and plant-growth-promoting endophytic bacterium, Pseudomonas aeruginosa L10, was isolated from the roots of a reed, Phragmites australis, in the Yellow River Delta, Shandong, China. P. aeruginosa L10 efficiently degraded C10-C26n-alkanes from diesel oil, as well as common polycyclic aromatic hydrocarbons (PAHs) such as naphthalene, phenanthrene, and pyrene. In addition, P. aeruginosa L10 could produce biosurfactant, which was confirmed by the oil spreading method, and surface tension determination of inocula. Moreover, P. aeruginosa L10 had plant growth-stimulating attributes, including siderophore and indole-3-acetic acid (IAA) release, along with 1-aminocyclopropane-1-carboxylic (ACC) deaminase activity. To explore the mechanisms underlying the phenotypic traits of endophytic P. aeruginosa L10, we sequenced its complete genome. From the genome, we identified genes related to petroleum hydrocarbon degradation, such as putative genes encoding monooxygenase, dioxygenase, alcohol dehydrogenase, and aldehyde dehydrogenase. Genome annotation revealed that P. aeruginosa L10 contained a gene cluster involved in the biosynthesis of rhamnolipids, rhlABRI, which should be responsible for the observed biosurfactant activity. We also identified two clusters of genes involved in the biosynthesis of siderophore (pvcABCD and pchABCDREFG). The genome also harbored tryptophan biosynthetic genes (trpAB, trpDC, trpE, trpF, and trpG) that are responsible for IAA synthesis. Moreover, the genome contained the ACC deaminase gene essential for ACC deaminase activity. This study will facilitate applications of endophytic P. aeruginosa L10 to phytoremediation by advancing the understanding of hydrocarbon degradation, biosurfactant synthesis, and mutualistic interactions between endophytes and host plants.

4.
3 Biotech ; 8(3): 137, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29479513

RESUMO

A new type of thermostable laccase was isolated from Paraphoma sp. GZS18, and its partial enzymatic properties were determined. A strain GZS18 of laccase with high yield was screened from forest soil and identified as Paraphoma sp. GZS18 through morphological characteristics and ITS sequence analysis. The laccase of Paraphoma sp. GZS18 (Lac-P) was obtained through cation-anion exchange chromatography, gel filtration chromatography, and other purification processes. The testing result shows that Lac-P is a single protein of 75 kDa, and the 11 amino acid sequences in the N-terminal are AXaVSVASREMT (Xa was the non-standard protein). The optimum temperature and optimum pH of lac-P activity are substrate-independent. The temperature is in the range of 50-70 °C, and pH has high catalytic efficiency in the acidic range. Lac-P has good stability in the temperature and pH. The half time at 70-60 °C is 1.5 and 4 h, respectively. At pH 6-9 and room temperature, there is more than 80% activity 24 h later. Lac-P is tolerant of most metal ions and low concentrations of inhibitors but is inhibited by Hg2+, Fe2+ and NaN3. The laccase from Paraphoma sp. GZS18 at high temperature and pH 6-9, with strong stability, has better industrial application characteristics.

5.
Sci Rep ; 7(1): 17801, 2017 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-29259312

RESUMO

Mixing cultures induces the biosynthesis of laccase in mixed cells, produces signal molecules, and regulates the production of mixed-cell metabolites. The fungal strain, which promotes laccase production, has been isolated and screened from the host bamboos of endophytic fungi and identified as Phoma sp. BZJ6. When the culture medium is mainly composed of soluble starch, yeast extract, and Phoma sp., the laccase output can reach 4,680 U/L. Nitric oxide (NO) and reactive oxygen species (ROS) were found to promote the regulation of laccase synthesis. Plasma membrane NAD(P)H oxidase inhibitors and NO-specific quenchers can inhibit not only the accumulation of ROS induced and NO synthesis but also the biosynthesis of laccase. The results indicate that the accumulation of superoxide anion radical (O2-) and hydrogen peroxide (H2O2) induced by the mixed culture was partially dependent on NO. The mixed culture can also reduce the biomass, increase the synthesis of total phenolics and flavonoids, and enhance the activity of phenylalanine ammonia-lyase and chalcone isomerase. This phenomenon is probably the result of the activated phenylpropanoids-flavonoid pathway. Results confirmed that the mixture culture is advantageous for laccase production and revealed that NO, O2-, and H2O2 are necessary signal molecules to induce laccase synthesis.

6.
Biochem Biophys Res Commun ; 494(3-4): 518-525, 2017 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-29079191

RESUMO

Redox homeostasis is important for maintenance of normal physiological functions within cells. Redox state of cells is primarily a consequence of precise balance between levels of reducing equivalents and reactive oxygen species. Redox homeostasis between peroxynitrite (ONOO-) and glutathione (GSH) is closely associated with physiological and pathological processes, such as prolonged relaxation in vascular tissues and smooth muscle preparations, attenuation of hepatic necrosis, and activation of matrix metalloproteinase-2. We report a two-photon fluorescent probe (TP-Se) based on water-soluble carbazole-based compound, which integrates with organic selenium, to monitor changes in ONOO-/GSH levels in cells. This probe can reversibly respond to ONOO- and GSH and exhibits high selectivity, sensitivity, and mitochondrial targeting. The probe was successfully applied to visualize changes in redox cycles during ONOO- outbreak and antioxidant GSH repair in cells. The probe will lead to significant development on redox events involved in cellular redox regulation.


Assuntos
Corantes Fluorescentes/química , Glutationa/metabolismo , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Mitocôndrias/metabolismo , Técnicas de Sonda Molecular , Ácido Peroxinitroso/metabolismo , Animais , Humanos , Camundongos , Mitocôndrias/ultraestrutura , Oxirredução , Células RAW 264.7
7.
Biochem Biophys Res Commun ; 488(2): 340-347, 2017 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-28499871

RESUMO

Malignant neoplasms exhibit an elevated rate of glycolysis and a high demand for glucose over normal cells. This characteristic can be exploited for in vivo imaging and tumor targeting examined. In this manuscript, we describe the synthesis of near-infrared (NIR) fluorochrome IR-822-labeled 2-amino-2-deoxy-d-glucose (DG) for optical imaging of tumors in mice. NIR fluorescent dye IR-820 was subsequently conjugated with 3-Mercaptopropionic acid and 2-amino-2-deoxy-d-glucose to form IR-822-DG. The cell experiments and acute toxicity studies demonstrated the low toxicity of IR-822-DG to normal cells/tissues. The dynamic behavior and targeting ability of IR-822-DG in normal mice was investigated with a NIR fluorescence imaging system. The in vitro and in vivo tumor targeting capabilities of IR-822-DG were evaluated in tumor cells and tumor bearing mice, respectively. Results demonstrated that IR-822-DG actively and efficiently accumulated at the site of the tumor. The probe also exhibited good photostability and excellent cell membrane permeability. The study indicates the broad applicability of IR-822-DG for tumors diagnosis, especially in the glucose-related pathologies.


Assuntos
Desoxiglucose/química , Corantes Fluorescentes/química , Neoplasias/diagnóstico , Animais , Linhagem Celular Tumoral , Desoxiglucose/síntese química , Corantes Fluorescentes/síntese química , Humanos , Camundongos , Camundongos Nus , Estrutura Molecular
8.
Biotechnol Lett ; 39(4): 491-499, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28050673

RESUMO

OBJECTIVE: Methionine is a valid target for the treatment of cancer and to achieve in vivo imaging and early diagnosis of tumors, we have synthesized near-infrared (NIR) fluorochrome IR-822-labeled methionine (IR-822-Met). RESULTS: NIR fluorescent dye IR-822 was conjugated with methionine through its amide bond. It had low toxicity to normal cell/tissues. In vitro and in vivo studies demonstrated its high targeting capability to tumors. The results support the potential of using ligand-modified methionine probe for tumor diagnosis and targeted therapy. The probe also exhibited good photostability, and excellent cell membrane permeability. CONCLUSION: IR-822-Met is a promising imaging agent for tumor diagnosis, especially in their early stage.


Assuntos
Carbocianinas/síntese química , Corantes Fluorescentes/síntese química , Metionina/síntese química , Neoplasias/diagnóstico por imagem , Imagem Óptica , Animais , Linhagem Celular Tumoral , Humanos , Células MCF-7 , Masculino , Camundongos , Camundongos Nus , Espectroscopia de Luz Próxima ao Infravermelho
9.
Biotechnol Lett ; 38(11): 1851-1856, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27484687

RESUMO

OBJECTIVE: To design and synthesize a novel near-infrared (NIR) fluorescent probe based on indocyanine Green (ICG), that can be applied in imaging living cells. RESULTS: A highly fluorescent novel NIR fluorescent probe (IR-793) was synthesized in two steps. IR-793 had better fluorescence and optical stability than ICG. In addition, no obvious cytotoxicity effect of IR-793 was observed and cell viability was above 75% at the maximum concentration (120 nM). IR-793 also exhibited good performance in imaging living A549 cells. CONCLUSION: IR-793, a novel NIR fluorescent probe that is stable, low-cost, highly fluorescent and low cytotoxicity, has been designed and synthesized for imaging living cells.


Assuntos
Corantes Fluorescentes/síntese química , Verde de Indocianina/química , Imagem Óptica/métodos , Células A549 , Sobrevivência Celular/efeitos dos fármacos , Corantes Fluorescentes/química , Corantes Fluorescentes/farmacologia , Humanos , Estrutura Molecular , Coloração e Rotulagem/métodos
10.
Colloids Surf B Biointerfaces ; 138: 60-9, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26655793

RESUMO

Multidrug resistance (MDR) remains one of major limitation for the successful treatment of many cancers including breast cancer. Co-delivery of chemotherapeutic drugs and small interfering RNA (siRNA) has been developed because of its ability to generate synergistic anticancer effects via different mechanisms of action, to reverse MDR and increase the efficacy of chemotherapeutic drugs in cancer therapy. Herein, we employed a kind of efficient multifunctional tumor targeted nanomicelles (PECL3) for the co-delivery of hydrophobic anti-cancer drugs and siRNA. This kind of nanomicelles were constructed by folic acid (FA)-decorated PEG-b-(PCL-g-PEI)-b-PCL triblock copolymers, which were synthesized through "click chemistry" and "ring opening" polymerization. Driven by the "core-shell" structure and the electrostatic interaction, this triblock copolymer could efficiently encapsulate P-glycoprotein (P-gp) siRNA and doxorubicin (DOX). The obtained nanomicelles can prevent renal clearance, RNase degradation and aggregation in circulation. Compared to the non-specific delivery, these FA functionalized nanomicelles could efficiently deliver P-gp siRNA to reducing both P-gp expression levels and IC50 value of the DOX in DOX-resistant breast cancer cells (MCF-7/ADR). Additionally, in vivo results showed that DOX loaded PECL3 (D-PECL3) micelles could reduce toxicity of DOX on nontarget tissues and significantly inhibited MCF-7/ADR tumor growth through encapsulating DOX in the micelles and deliver them to target tumor region. Taken together, these results proof that PECL3 micelles could co-deliver siRNA and drug to inhibit MDR tumor growth. These results suggested that the co-delivery of DOX and siRNA in tumor-targeting nanomicelles could excite synergistic effect of gene therapy and chemotherapy, thus can efficiently reverse MDR cancer and kill the cancer cells.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Doxorrubicina/farmacologia , Interferência de RNA , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacocinética , Antibióticos Antineoplásicos/farmacologia , Neoplasias da Mama/patologia , Terapia Combinada , Doxorrubicina/química , Doxorrubicina/farmacocinética , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Ácido Fólico/química , Humanos , Células MCF-7 , Micelas , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Nanopartículas/administração & dosagem , Nanopartículas/química , Nanopartículas/ultraestrutura , Terapêutica com RNAi/métodos , Carga Tumoral/efeitos dos fármacos , Carga Tumoral/genética , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
11.
Bioorg Med Chem ; 23(13): 3457-71, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25953722

RESUMO

In our study, three series of hydroxamate, 2-aminobenzamide, and trifluoromethyl ketone analogues have been designed and synthesized. The synthesized compounds were investigated for their in vitro antiproliferative activities using the MTT-based assay against three human cancer cell lines including A549, NCI-H661, and U937. Most analogues exhibited higher antiproliferative activities against human acute myeloid leukemia cell U937 than the other two human lung cancer cell lines. Furthermore, the compounds were examined against HDAC1, 2, and 8 isoforms. Docking study of compounds 6h, 9b, and 10a suggested that they might bind tightly to the binding pocket of HDAC2 and/or HDAC8. The results suggest that these compounds might have potential as lead compounds for the development of anti-tumor drugs with HDACs inhibitory activities.


Assuntos
Antineoplásicos/síntese química , Histona Desacetilase 1/antagonistas & inibidores , Histona Desacetilase 2/antagonistas & inibidores , Inibidores de Histona Desacetilases/síntese química , Ácidos Hidroxâmicos/química , Oxidiazóis/síntese química , Proteínas Repressoras/antagonistas & inibidores , Antineoplásicos/farmacologia , Sítios de Ligação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Descoberta de Drogas , Ensaios de Seleção de Medicamentos Antitumorais , Histona Desacetilase 1/metabolismo , Histona Desacetilase 2/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Humanos , Ácidos Hidroxâmicos/farmacologia , Concentração Inibidora 50 , Cetonas/química , Simulação de Acoplamento Molecular , Oxidiazóis/farmacologia , Ligação Proteica , Proteínas Repressoras/metabolismo , Relação Estrutura-Atividade , Vorinostat , ortoaminobenzoatos/química
12.
Eur J Med Chem ; 96: 1-13, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25874326

RESUMO

Using Entinostat as a lead compound, 2-aminobenzamide and hydroxamate derivatives have been designed and synthesized. The entire target compounds were investigated for their in vitro antiproliferative activities using the MTT-based assay against five human cancer cell lines including U937, A549, NCI-H661, MDA-MB-231 and HCT116. 2-Aminobenzamide series of compounds (10a-10j) demonstrated the most significant inhibition against human acute monocytic myeloid leukemia cell line U937, but no or poor activities against two human lung cancer cell lines. Furthermore, the target compounds were screened for their inhibitory activities against HDAC 1, 2, and 8. 2-Aminobenzamide derivatives (10) manifested a higher selectivity for HDAC 1 over HDAC 2, but were not active against HDAC 8. In contrast, most hydroxamate derivatives (11) inhibit HDAC 8 with lower IC50 values than SAHA and Entinostat. Docking study with selected compounds 10f and 11a revealed that the compounds might bind tightly to the binding pockets in HDAC 2 and HDAC 8, respectively. The results suggest that they may be promising lead compounds for the development of novel anti-tumor drug potentially via inhibiting HDACs.


Assuntos
Descoberta de Drogas , Inibidores de Histona Desacetilases/farmacologia , Ácidos Hidroxâmicos/farmacologia , Oxidiazóis/farmacologia , ortoaminobenzoatos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Histona Desacetilase 2/antagonistas & inibidores , Histona Desacetilase 2/metabolismo , Inibidores de Histona Desacetilases/síntese química , Inibidores de Histona Desacetilases/química , Histona Desacetilases/metabolismo , Humanos , Ácidos Hidroxâmicos/síntese química , Ácidos Hidroxâmicos/química , Modelos Moleculares , Estrutura Molecular , Oxidiazóis/química , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/metabolismo , Relação Estrutura-Atividade , ortoaminobenzoatos/síntese química , ortoaminobenzoatos/química
13.
Bioorg Med Chem ; 23(4): 657-67, 2015 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-25614116

RESUMO

A series of phenoxybutanoic acid derivatives were synthesized and tested for their antagonistic activity on the contraction of the rat thoracic aortic ring induced by endothelin-1. Preliminary screening results showed that 6e and 6g with benzoheterocycles demonstrated significant antagonistic activities when compared to the reference compound BQ123. The results from additional assays for the binding affinity and selectivity for endothelin receptors showed that 6e was a selective ETA antagonist with a nanomolar IC50. Moreover, 6e was effective in relieving hypoxia-induced pulmonary arterial hypertension and right ventricular weight ratio. Therefore, 6e may have potential for further development as a therapeutic agent for the treatment of cardiovascular diseases.


Assuntos
Anti-Hipertensivos/química , Anti-Hipertensivos/farmacologia , Butiratos/química , Butiratos/farmacologia , Antagonistas dos Receptores de Endotelina/química , Antagonistas dos Receptores de Endotelina/farmacologia , Vasoconstrição/efeitos dos fármacos , Animais , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/fisiologia , Descoberta de Drogas , Modelos Moleculares , Ratos , Ratos Sprague-Dawley , Receptores de Endotelina/metabolismo , Relação Estrutura-Atividade
14.
Appl Biochem Biotechnol ; 175(3): 1644-50, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25416478

RESUMO

IR-780, a novel near-infrared (NIR) fluorescent probe, was synthesized and applied to living cells. The probe exhibited good fluorescent characteristic, and cell experiments showed the probe had high affinity and without apparent cytotoxicity. Fluorescent image experiments in living A549 (Human lung adenocarcinoma epithelial cell line) and L929 (mouse fibroblast cell line) cells, further demonstrated its potential applications in biological systems. The probe effectively prevented the influence of autofluorescence and native cellular species in biological systems. It also exhibited excellent cell membrane permeability, good photostability, and high sensitivity.


Assuntos
Corantes Fluorescentes/síntese química , Indóis/síntese química , Imagem Molecular/métodos , Espectroscopia de Luz Próxima ao Infravermelho , Animais , Linhagem Celular , Sobrevivência Celular , Corantes Fluorescentes/química , Humanos , Indóis/química , Camundongos , Microscopia Confocal , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Fluorescência
15.
Biotechnol Lett ; 36(6): 1203-7, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24563309

RESUMO

IR-789, a novel near-infrared fluorescent probe, was designed, synthesized, and applied to living cells. The probe exhibited better response fluorescence characteristics than the only FDA-approved agent, indocyanine green. Cell experiments showed that the probe had high affinity and without apparent cytotoxicity. Fluorescent image experiments in living MCF-7 cells (human breast adenocarcinoma cell line) further demonstrated the potential applications of the probe in biological systems. The probe effectively prevented the influence of autofluorescence and native cellular species in biological systems. It also exhibited high sensitivity, good photostability, and excellent cell membrane permeability.


Assuntos
Corantes Fluorescentes/análise , Corantes Fluorescentes/síntese química , Células MCF-7/fisiologia , Imagem Óptica/métodos , Coloração e Rotulagem/métodos , Humanos
16.
Appl Biochem Biotechnol ; 172(2): 1036-44, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24142355

RESUMO

A new near-neutral pH near-infrared (NIR) fluorescent probe utilizing a fluorophore-receptor molecular framework that can modulate the fluorescence emission intensity through a fast photoinduced electron transfer process was developed. Our strategy was to choose tricarbocyanine (Cy), a NIR fluorescent dye with high extinction coefficients, as a fluorophore, and N-methylpiperazine (MP) as a receptor. The pH titration indicated that MP-Cy can monitor the minor physiological pH fluctuations with a pKa of ∼7.10 near physiological pH, which is valuable for intracellular pH researches. The probe responds linearly and rapidly to minor pH fluctuations within the range of 3.05-7.10 and exhibits strong dependence on pH changes. As expected, the real-time imaging of cellular pH and the detection of pH in situ was achieved successfully in living HepG2 cells by this probe. It is shown that the probe effectively avoids the influence of autofluorescence and native cellular species in biological systems and meanwhile exhibits high sensitivity, good photostability, and excellent cell membrane permeability.


Assuntos
Diagnóstico por Imagem/métodos , Corantes Fluorescentes , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Absorção , Carbocianinas , Sobrevivência Celular , Corantes Fluorescentes/química , Células Hep G2 , Humanos , Concentração de Íons de Hidrogênio , Microscopia Confocal , Piperazinas , Espectrometria de Fluorescência
17.
Folia Microbiol (Praha) ; 58(4): 283-9, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23229285

RESUMO

Some endophyte isolates were isolated in a bamboo pole sample parasitized the fungus Shiraia bambusicola from Zhejiang Province. After screening through hypocrellin bacteriostatic effect and fermentation test, we got the isolate TX4 of bacterial elicitor and GZUIFR-TT1 of fungal elicitor which had certain effect to promote S. bambusicola to produce hypocrellin. The Plackett-Burman design was introduced to evaluate the effects of nine factors based on single-factor test. Yeast extract, glucose, and isolate GZUIFR-TT1 elicitor were found to be the critical activity factors for increasing the total hypocrellin production. So we identified the isolate GZUIFR-TT1 as Trametes sp. Through response surface methodology, we obtained the optimum production conditions as follows: yeast extract, 2.99 g/L; glucose, 32.45 g/L; and Trametes sp. elicitor, 81.40 µg/mL. Under the above conditions, the experimental value of hypocrellin production was 102.60 mg/L, compared with the control it increased about 7.90 times.


Assuntos
Anti-Infecciosos/metabolismo , Ascomicetos/metabolismo , Perileno/análogos & derivados , Quinonas/metabolismo , Trametes/crescimento & desenvolvimento , Biotecnologia/métodos , Meios de Cultura/química , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Fermentação , Dados de Sequência Molecular , Perileno/metabolismo , Análise de Sequência de DNA , Trametes/classificação , Trametes/genética , Trametes/isolamento & purificação
18.
Appl Biochem Biotechnol ; 168(8): 2376-86, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23079890

RESUMO

In this study, an easily detectable method was employed for screening laccase-producing microorganisms by using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) as laccase secretion indicator. A novel laccase-producing strain was isolated and identified as Shiraia bambusicola Henn. strain GZ11K2 according to the morphological characteristics and the comparison of internal transcribed spacer ribosomal DNA gene sequences. In further investigation, the production of laccase by S. bambusicola GZ11K2 was greatly enhanced by the nontoxic inducers of copper sulfate and rhodamine B. Copper and rhodamine B were added into the cultivation medium at 24 and 12 h, respectively, and the maximum laccase production was obtained. Under the induction of 2.0 mM copper sulfate and 35 µM rhodamine B, an increment of about 80 times of laccase activity compared with that in the inducer-free medium and about 20 times compared with that in the single copper-supplemented medium was observed. Compared with other species, S. bambusicola GZ11K2 exhibits better laccase-producing characteristics with an activity of 16,400 U/L after 108 h, suggesting its potential ability for industrial application.


Assuntos
Ascomicetos/metabolismo , Lacase/biossíntese , Ascomicetos/citologia , Ascomicetos/efeitos dos fármacos , Ascomicetos/crescimento & desenvolvimento , Benzotiazóis/farmacologia , Cobre/farmacologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Espaço Extracelular/efeitos dos fármacos , Espaço Extracelular/enzimologia , Rodaminas/farmacologia , Ácidos Sulfônicos/farmacologia , Fatores de Tempo
19.
PLoS One ; 7(8): e43026, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22937009

RESUMO

Foods high in resistant starch (RS) are beneficial to prevent various diseases including diabetes, colon cancers, diarrhea and chronic renal or hepatic diseases. Elevated RS in rice is important for public health since rice is a staple food for half of the world population. A japonica mutant 'Jiangtangdao 1' (RS = 11.67%) was crossed with an indica cultivar 'Miyang 23' (RS = 0.41%). The mutant sbe3-rs that explained 60.4% of RS variation was mapped between RM6611 and RM13366 on chromosome 2 (LOD = 36) using 178 F(2) plants genotyped with 106 genome-wide polymorphic SSR markers. Using 656 plants from four F(3:4) families, sbe3-rs was fine mapped to a 573.3 Kb region between InDel 2 and InDel 6 using one STS, five SSRs and seven InDel markers. SBE3 which codes for starch branching enzyme was identified as a candidate gene within the putative region. Nine pairs of primers covering 22 exons were designed to sequence genomic DNA of the wild type for SBE3 and the mutant for sbe3-rs comparatively. Sequence analysis identified a missense mutation site where Leu-599 of the wild was changed to Pro-599 of the mutant in the SBE3 coding region. Because the point mutation resulted in the loss of a restriction enzyme site, sbe3-rs was not digested by a CAPS marker for SpeI site while SBE3 was. Co-segregation of the digestion pattern with RS content among 178 F(2) plants further supported sbe3-rs responsible for RS in rice. As a result, the CAPS marker could be used in marker-assisted breeding to develop rice cultivars with elevated RS which is otherwise difficult to accurately assess in crops. Transgenic technology should be employed for a definitive conclusion of the sbe3-rs.


Assuntos
Enzima Ramificadora de 1,4-alfa-Glucana/genética , Genes de Plantas/genética , Oryza/enzimologia , Oryza/genética , Cromossomos de Plantas/genética , Dados de Sequência Molecular , Mutação
20.
World J Microbiol Biotechnol ; 28(11): 3151-7, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22864599

RESUMO

The antibacterial activity and acting mechanism of hypocrellin A (HA) were conducted regarding in vitro activity of HA on Staphylococcus aureus GZ86 by analyzing the growth, permeability, and morphology of the bacterial cells following treatment with HA. The experimental results indicated 1.5 mg/l HA could completely inhibit the growth of 107 CFU/ml S. aureus cells in liquid beef extract-peptone medium under a halogen-tungsten lamp for 120 min. Meanwhile, HA resulted in the leakage of reducing sugars and proteins and induced the respiratory chain dehydrogenases into inactive state, suggesting that HA were able to destroy the permeability of the bacterial membranes. When the cells of S. aureus were exposed to 2.5 mg/l HA under a halogen-tungsten lamp for 120 min, many pits and gaps were observed in bacterial cells by scanning electron microscopy, and the cell wall was fragmentary, indicating the bacterial cells were damaged severely. The experiments strongly confirmed the contribution of multiform reactive oxygen species (ROS) to bactericidal effect. In conclusion, the combined results suggested that ROS may damage the structure of bacterial cell wall and depress the activity of some membranous enzymes, which cause S. aureus bacteria to die eventually.


Assuntos
Antibacterianos/farmacologia , Perileno/análogos & derivados , Quinonas/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Meios de Cultura/química , Inibidores Enzimáticos/farmacologia , Microscopia Eletrônica de Varredura , Oxirredutases/antagonistas & inibidores , Perileno/farmacologia , Staphylococcus aureus/citologia , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/fisiologia
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