Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-38591772

RESUMO

Two yeast strains, designated as 19-39-3 and 19-40-2, obtained from the fruiting bodies of Trametes versicolor and Marasmius siccus collected in Yunwu Mountain Forest Park, PR China, have been identified as representing a novel asexual ascomycetous yeast species. From the results of phylogenetic analyses of the sequences of the D1/D2 domains of the large subunit (LSU) rRNA, small subunit (SSU) rRNA and translation elongation factor 1-α (TEF1) genes, it was determined that these strains represent a member of the genus Wickerhamomyces, with Wickerhamomyces alni and Candida ulmi as the closest relatives. The novel species exhibited 6.6 and 6.7% differences in the D1/D2 domains compared with W. alni and C. ulmi, respectively. Additionally, distinct biochemical and physiological differences were observed between the novel species and its related counterparts. No sexual reproduction was observed in these strains, leading to the proposal of the name Wickerhamomyces corioli f.a., sp. nov. for this newly discovered species.


Assuntos
Agaricales , Saccharomycetales , Filogenia , DNA Espaçador Ribossômico/genética , Agaricales/genética , Trametes/genética , Análise de Sequência de DNA , Composição de Bases , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Ácidos Graxos/química , Saccharomycetales/genética , DNA Fúngico/genética , Técnicas de Tipagem Micológica
2.
Anal Chem ; 96(8): 3561-3568, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38372135

RESUMO

Covalent organic frameworks (COFs) are attractive adsorbents for sample pretreatment due to their unique structure and properties. However, the selectivity of COFs for the extraction of hazardous compounds is still limited due to the lack of specific interactions between COFs and targets. Herein, we report a pore size adjustment strategy for room-temperature synthesis of molecularly imprinted COF (MICOF) for selective extraction of zearalenone (ZEN) in complex food samples. The three-dimensional building block tetra(4-aminophenyl) methane was used as a functional monomer, while dialdehyde monomers with different numbers of benzene ring were used to adjust the pore size of MICOF to match with the size of ZEN molecules. The prepared MICOF gave the largest adsorption capacity of 177.2 mg g-1 and the highest imprinting factor of 10.1 for ZEN so far. MICOF was used as the adsorbent for dispersed solid-phase extraction in combination with high-performance liquid chromatography for the determination of trace ZEN in cereals. The high selectivity of the developed method allows simple aqueous standard calibration for the matrix effect-free determination of ZEN in food samples. The limit of detection and the recoveries of the developed method were 0.21 µg kg-1 and 93.7-101.4%, respectively. The precision for the determination of ZEN was less than 3.8% (RSD, n = 6). The developed method is promising for the selective determination of ZEN in complex matrices.


Assuntos
Estruturas Metalorgânicas , Nanosferas , Zearalenona , Estruturas Metalorgânicas/química , Zearalenona/análise , Grão Comestível/química , Temperatura , Cromatografia Líquida de Alta Pressão/métodos , Extração em Fase Sólida/métodos , Adsorção
3.
J Mater Chem B ; 11(46): 11094-11102, 2023 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-37987617

RESUMO

Covalent organic frameworks (COFs) have promising applications in enhanced phototherapy. However, COFs that can sustainably play a role in phototherapy without continuous irradiation are extremely scarce. Herein, we report the fabrication of porphyrin-anthracene multifunctional COFs (Por-DPA) for sustainable photosterilization and bacterial-infected wound healing. A porphyrin photosensitizer, as one of the monomers, was used to provide photothermal and photodynamic activities under irradiation. An anthracene derivative, a good chemical source of singlet oxygen (1O2), was selected as another monomer to capture 1O2 and release it continuously via cycloreversion in the dark. The prepared Por-DPA COF prevents the self-aggregation quenching of the photosensitizer and thermal damage caused by continuous exposure to external light sources. Besides, Por-DPA exhibits good photothermal conversion performance and efficient 1O2 production capacity through dual pathways of photosensitization and cycloreversion. The developed sustainable photosterilization platform not only has good bactericidal effects on Escherichia coli and Staphylococcus aureus, but also promotes wound healing without obvious side effects, and is expected to be a novel efficient bactericide.


Assuntos
Estruturas Metalorgânicas , Porfirinas , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/química , Estruturas Metalorgânicas/farmacologia , Estruturas Metalorgânicas/química , Porfirinas/farmacologia , Porfirinas/química , Fototerapia , Oxigênio Singlete/metabolismo
4.
ACS Appl Mater Interfaces ; 15(33): 39669-39676, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37579002

RESUMO

Thermally activated delayed fluorescence (TADF) emitters based on multiple resonance (MR) effects are promising for high-definition organic light-emitting diodes (OLEDs) with narrowband emission and high efficiency. However, they still face the challenges of aggregation-caused quenching (ACQ) and spectral broadening. Solution-processable MR-TADF emitters with an external quantum efficiency (EQE) of >20% and a full width at half-maximum (fwhm) of <30 nm have rarely been reported. To construct ACQ-resistant emitters without sacrificing color purity, the aggregation-induced MR-TADF material 6TBN with a rigid B,N-containing polycyclic aromatic hydrocarbon core and four carbazole substituents as well as 12 tert-butyl groups on the periphery is designed. The multidimensional shielded effect largely limits the ACQ, intermolecular interactions, and spectral broadening. Consequently, solution-processed OLEDs based on 6TBN exhibit a maximum EQE of 23.0% and high color purity with a fwhm of 25 nm. Furthermore, the nondoped device achieves a high efficiency (12.3%) and merely a slight widening of the fwhm to 27 nm. This work provides a feasible strategy to achieve MR-TADF materials with resistance to concentration quenching and high color purity.

5.
Angew Chem Int Ed Engl ; 61(49): e202213823, 2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-36206365

RESUMO

Organic materials featuring intramolecular through-space charge transfer (TSCT) excited states are advantageous for efficient thermally activated delayed fluorescence (TADF), although the realization of multiple TSCT systems remains challenging. Herein, a rigid molecule with a three-dimensional dislocated sandwich acceptor-donor-acceptor configuration has been developed by a linking biphenazine (2PXZ) donor and 2,4,6-triphenyl-1,3,5-triazine (TRZ) acceptor through the twin-locking of two spiro-fluorene bridges. The twin-locking construction with multiple TSCT effects suppresses the intramolecular rotations of various segments in 2PXZ-2TRZ, leading to a small singlet-triplet energy difference, a fast reverse intersystem crossing process, and high photoluminescence quantum yield. This material simultaneously possesses the capabilities of TADF and aggregation-induced emission. The device employing 2PXZ-2TRZ as a dopant displays an optimal external quantum efficiency of 27.1 % and a low efficiency roll-off.

6.
World J Gastroenterol ; 26(32): 4802-4816, 2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32921958

RESUMO

BACKGROUND: Multiple sites of metastasis and desmoplastic reactions in the stroma are key features of human pancreatic cancer (PC). There are currently no simple and reliable animal models that can mimic these features for accurate disease modeling. AIM: To create a new xenograft animal model that can faithfully recapitulate the features of human PC. METHODS: Interleukin 2 receptor subunit gamma (IL2RG) gene knockout Syrian hamster was created and characterized. A panel of human PC cell lines were transplanted into IL2RG knockout Syrian hamsters and severe immune-deficient mice subcutaneously or orthotopically. Tumor growth, local invasion, remote organ metastasis, histopathology, and molecular alterations of tumor cells and stroma were compared over time. RESULTS: The Syrian hamster with IL2RG gene knockout (named ZZU001) demonstrated an immune-deficient phenotype and function. ZZU001 hamsters faithfully recapitulated most features of human PC, in particular, they developed metastasis at multiple sites. PC tissues derived from ZZU001 hamsters displayed desmoplastic reactions in the stroma and epithelial to mesenchymal transition phenotypes, whereas PC tissues derived from immune-deficient mice did not present such features. CONCLUSION: ZZU001 hamsters engrafted with human PC cells are a superior animal model compared to immune-deficient mice. ZZU001 hamsters can be a valuable animal model for better understanding the molecular mechanism of tumorigenesis and metastasis and the evaluation of new drugs targeting human PC.


Assuntos
Transição Epitelial-Mesenquimal , Neoplasias Pancreáticas , Animais , Cricetinae , Modelos Animais de Doenças , Xenoenxertos , Humanos , Mesocricetus , Camundongos , Neoplasias Pancreáticas/genética
7.
ACS Appl Mater Interfaces ; 11(29): 26144-26151, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31298023

RESUMO

The design and synthesis of highly efficient thermally activated delayed fluorescence (TADF) emitters with an electroluminescence wavelength beyond 600 nm remains a great challenge for organic light-emitting diodes (OLEDs). To solve this issue, three TADF molecules, xDMAC-BP (x = 1, 2, 3), are developed in combination with the rigid planar dibenzo[a,c]phenazine (BP) acceptor core and different numbers of 9,9-dimethylacridan (DMAC) donors. All these emitters possess stable internal charge transfer and a large dihedral angle between the donors and planar BP core. The emission wavelength can be regulated from 541 to 605 nm by increasing the number of the donor DMAC units because of the controllable tuning of the intramolecular charge transfer effect and the molecular geometrical structure. The photoluminescence quantum yields of these emitters are improved from 42 to 89% with the increase in the number of DMAC units. The orange-red OLEDs employing the xDMAC-BP emitters exhibit maximum external quantum efficiency (EQE) of 22.0% at 606 nm, which is the highest EQE of the previously reported TADF OLEDs exceeding 600 nm.

8.
J Asian Nat Prod Res ; 21(6): 501-506, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29882413

RESUMO

One new polyacetylene glycoside eprostrata Ⅰ (1), together with seven known compounds (2-8), were isolated from Eclipta prostrata. Their structures were elucidated on the basis of spectroscopic and physico-chemical analyses. All the isolates were evaluated inhibitory activity on DGAT in an in vitro assay. Compounds 1-8 were found to exhibit inhibitory activity of DGAT1 with IC50 values ranging from 74.4 ± 1.3 to 101.1 ± 1.1 µM.


Assuntos
Diacilglicerol O-Aciltransferase/antagonistas & inibidores , Eclipta/química , Polímero Poliacetilênico/química , Polímero Poliacetilênico/farmacologia , Animais , Configuração de Carboidratos , Concentração Inibidora 50 , Fígado/efeitos dos fármacos , Fígado/enzimologia , Espectroscopia de Ressonância Magnética , Caules de Planta/química , Ratos
9.
Fitoterapia ; 128: 130-134, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29772304

RESUMO

A new bakuchiol compound Δ11-12-hydroxy-12-dimethyl bakuchiol (1), a new flavanone compound 2(S)-6-methoxy-7- hydroxymethylene-4'-hydroxyl-flavanone (8), and two new isoflavanone compounds 4',7-dihydroxy-3'-(6"ß-hydroxy-3″,7″-dimethyl-,2″,7″-dibutenyl)-geranylisoflavone (9) and 4',7-dihydroxy-3'-(7″-hydroxy-7″-methyl-2″,5″-dibutenyl)-geranylisoflavone (10) together with eight known compounds (2-7, 11, 12) were isolated from the P. corylifolia. Their structures were elucidated on the basis of spectroscopic and physico-chemical analyses. All the isolates were evaluated for in vitro inhibitory activity against DGAT1/2. Among them, compounds 3, 9 and 10 were found to exhibit selective inhibitory activity on DGAT1 with IC50 values ranging from 93.7 ±â€¯1.3 to 96.2 ±â€¯1.1 µM. Compound 1 showed inhibition activity on DGAT1 with IC50 values 73.4 ±â€¯1.3 µM and inhibition of DGAT2 with IC50 value 121.1 ±â€¯1.3 µM.


Assuntos
Diacilglicerol O-Aciltransferase/antagonistas & inibidores , Isoflavonas/isolamento & purificação , Fenóis/isolamento & purificação , Psoralea/química , Estrutura Molecular , Sementes/química
10.
Fitoterapia ; 121: 58-63, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28676388

RESUMO

Four new compounds, erythro-7'E-4-hydroxy-3,3'-dimethoxy-8,5'-oxyneoligna-7'-ene-7,9-diol-9'-al (1), (7S,8S)-4-hydroxy-3,1',3'-trimethoxy-4',7-epoxy-8,5'-neolign-9-ol (5), (7S,8S,7'E)-5-hydroxy-3,3'-dimethoxy-4',7-epoxy-8,5'-neolign-7'-ene-9,9'-diol (6) and (7S,8S,7'E)-5-hydroxy-3,3',9'-trimethoxy-4'-7-epoxy-8,5'-neolign-7'-ene-9-ol (7). Along with four known compounds (2-4, 8) were isolated from the EtOAc-soluble extract of Eleutherococcus senticosus. Their structures were elucidated on the basis of spectroscopic and physicochemical analyses. All the compounds were evaluated for in vitro inhibitory activity against PTP1B, VHR and PP1. Among them, compounds 1-4 and 6-8 were found to exhibit selective inhibitory activity on PTP1B with IC50 values ranging from 17.2±1.6 to 32.7±1.2µM.


Assuntos
Eleutherococcus/química , Lignanas/farmacologia , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Lignanas/isolamento & purificação , Estrutura Molecular , Caules de Planta/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA