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1.
J Enzyme Inhib Med Chem ; 39(1): 2403736, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39316789

RESUMO

Acyl-CoA: cholesterol acyltransferase (ACAT), a pivotal enzyme in the absorption and metabolism of cholesterol, is primarily responsible for intracellular esterification. ACAT inhibition is expected to diminish plasma lipid levels by impeding intestinal cholesterol absorption, thereby preventing the progression of atherosclerotic lesions. A previous study shows that selective inhibition of ACAT2 significantly mitigated hypercholesterolaemia and atherosclerosis in mouse models. Therefore, the need for ACAT2 selective inhibitors becomes particularly urgent. In this study, we established a multilayer virtual screening workflow and subjected biologically evaluated representative compounds to enzyme inhibitory assays. The experimental results indicated that the two compounds, STL565001 (inhibition rate at 25 µM: 75.7 ± 27.8%, selectivity = 6) and STL528213 (inhibition rate at 25 µM: 87.8 ± 12.4%, selectivity = 13), demonstrated robust activity against ACAT2, displaying greater selectivity for ACAT2 than for ACAT1. The molecular mechanisms governing the inhibitory activities of the selected compounds were systematically elucidated using computational approaches. In addition, hotspot residues in ACAT2 that are crucial for ligand binding were successfully identified. In summary, we devised a multilayer screening scheme to expeditiously and efficiently identify compounds with enzyme inhibitory activity, offering novel scaffolds for subsequent drug design centred on ACAT2 targets.


Assuntos
Relação Dose-Resposta a Droga , Descoberta de Drogas , Inibidores Enzimáticos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Esterol O-Aciltransferase 2 , Esterol O-Aciltransferase , Relação Estrutura-Atividade , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/síntese química , Esterol O-Aciltransferase/antagonistas & inibidores , Esterol O-Aciltransferase/metabolismo , Humanos , Estrutura Molecular , Farmacóforo
2.
Development ; 147(15)2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32816902

RESUMO

The evolutionarily conserved lethal-7 (let-7) microRNAs (miRNAs) are well-known activators of proliferative quiescence and terminal differentiation. However, in the murine auditory organ, let-7g overexpression delays the differentiation of mechano-sensory hair cells (HCs). To address whether the role of let-7 in auditory-sensory differentiation is conserved among vertebrates, we manipulated let-7 levels within the chicken auditory organ: the basilar papilla. Using a let-7 sponge construct to sequester let-7 miRNAs, we found that endogenous let-7 miRNAs are essential for limiting the self-renewal of HC progenitor cells. Furthermore, let-7b overexpression experiments revealed that, similar to mice, higher than normal let-7 levels slow/delay HC differentiation. Finally, we identify CHD7, a chromatin remodeler, as a candidate for mediating the repressive function of let-7 in HC differentiation and inner ear morphogenesis. Our analysis uncovered an evolutionarily conserved let-7-5p-binding site within the chicken Chd7 gene and its human and murine homologs, and we show that let-7g overexpression in mice limits CHD7 expression in the developing inner ear, retina and brain. Haploinsufficiency of CHD7 in humans causes CHARGE syndrome and attenuation of let-7 function may be an effective method for treating CHD7 deficiency.


Assuntos
Proteínas Aviárias/biossíntese , Galinhas/metabolismo , DNA Helicases/biossíntese , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Células Ciliadas Auditivas/metabolismo , MicroRNAs/metabolismo , Células-Tronco/metabolismo , Animais , Proteínas Aviárias/genética , Diferenciação Celular , Embrião de Galinha , Galinhas/genética , DNA Helicases/genética , Células Ciliadas Auditivas/citologia , Humanos , Camundongos , MicroRNAs/genética , Células-Tronco/citologia
3.
Appl Microbiol Biotechnol ; 104(17): 7573-7588, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32656616

RESUMO

Reductive soil disinfestation (RSD) is an effective agricultural practice to eliminate soil-borne pathogens that heavily relies on the organic substrate used. However, the influences of combined application of organic residues on disinfestation efficiency, soil microbiomes, and their associated functional characteristics are still not well-characterized. In this work, four treatments, i.e., untreated soil (CK), RSD with 15 t ha-1 sugarcane bagasse (SB), bean dregs (BD), and their combinations (1:1, SB+BD), were conducted to investigate their influence on disinfestation efficiency, microbial functional diversity, community diversity, and composition using Biolog analysis, real-time PCR, and high-throughput sequencing. The SB+BD treatment had synergetic effects on soil microbial activity, metabolic activity, and functional diversity with similar efficacy in pathogen elimination and soil salinization alleviation, as compared to the SB and BD treatments. Moreover, the SB+BD treatment distinctly altered the structure and composition of bacterial and fungal communities, especially enriched the core microbiomes associated with soil general functions such as organic decomposition and nitrate removal. The SB+BD treatment also strengthened the soil specific functions including disease suppression through the regulation of unique microbiomes. In addition, the microbial richness, diversity, and evenness were significantly higher in the SB+BD-treated soil as compared to the SB- and BD-treated soils. Taken together, RSD incorporated with organic residue combination not only efficiently restore the degraded soils, but also considerably improve soil functions, which may benefit to the health for the future plant generations. KEY POINTS: • Organic residue combination effectively declines pathogen density. • Organic residue combination improves soil microbial activity and functional diversity. • The enriched core microbiome is responsible for soil general functions. • The induced unique microbiome is important for soil specific functions.


Assuntos
Saccharum , Solo , Agricultura , Grão Comestível , Microbiologia do Solo
4.
Chemistry ; 22(27): 9299-304, 2016 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-27243145

RESUMO

Two novel polyoxometalate (POM)-based coordination polymers, namely, [Co(bpz)(Hbpz)][Co(SO4 )0.5 (H2 O)2 (bpz)]4 [PMo(VI) 8 Mo(V) 4 V(IV) 4 O42 ]⋅13 H2 O (NENU-530) and [Ni2 (bpz)(Hbpz)3 (H2 O)2 ][PMo(VI) 8 Mo(V) 4 V(IV) 4 O44 ]⋅8 H2 O (NENU-531) (H2 bpz=3,3',5,5'-tetramethyl-4,4'-bipyrazole), were isolated by hydrothermal methods, which represented 3D networks constructed by POM units, the protonated ligand and sulfate group. In contrast with most POM-based coordination polymers, these two compounds exhibit exceptional excellent chemical and thermal stability. More importantly, NENU-530 shows a high proton conductivity of 1.5×10(-3)  S cm(-1) at 75 °C and 98 % RH, which is one order of magnitude higher than that of NENU-531. Furthermore, structural analysis and functional measurement successfully demonstrated that the introduction of sulfate group is favorable for proton conductivity. Herein, the syntheses, crystal structures, proton conductivity, and the relationship between structure and property are presented.

5.
Chemistry ; 21(27): 9784-9, 2015 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-26015079

RESUMO

A series of isoreticular metal-organic frameworks (MOFs; NENU-511-NENU-514), which all have high surface areas and strong adsorption capacities, have been successfully constructed by using mixed ligands. NENU-513 has the highest benzene capacity of 1687 mg g(-1) at 298 K, which ranks as the top MOF material among those reported up to now. This NENU series has been used for adsorptive desulfurization because of its permanent porosity. The results indicate that this series has a higher adsorptive efficiency in the removal of organosulfur compounds than other MOF materials, especially NENU-511, which has the highest adsorptive efficiency in the ambient atmosphere. This study proves that the design and synthesis of targeted MOFs with higher surface areas and with functional groups present is an efficient method to enhance benzene-storage capacity and the adsorption of organosulfur compounds.

6.
Inorg Chem ; 54(7): 3290-6, 2015 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-25768042

RESUMO

A stable porous carbazole-based luminescent metal-organic framework, NENU-522, was successfully constructed. It is extremely stable in air and acidic/basic aqueous solutions, which provides the strategy for luminescent material encapsulation of Ln(3+) ions with tunable luminescence for application in light emission. More importantly, Ln(3+)@NENU-522 can emit white light by encapsulating different molar ratios of Eu(3+) and Tb(3+) ions. Additionally, Tb(3+)@NENU-522 is found to be useful as a fluorescent indicator for the qualitative and quantitative detection of nitroaromatic explosives with different numbers of -NO2 groups, and the concentrations of complete quenching are about 2000, 1000, and 80 ppm for nitrobenzene, 1,3-dinitrobenzene, and 2,4,6-trinitrophenol, respectively. Meanwhile, Tb(3+)@NENU-522 displays high selectivity and recyclability in the detection of nitroaromatic explosives.


Assuntos
Substâncias Explosivas/análise , Elementos da Série dos Lantanídeos/química , Luz , Nitrocompostos/química , Compostos Organometálicos/química , Cristalografia por Raios X , Substâncias Explosivas/química , Luminescência
7.
Chemistry ; 20(19): 5625-30, 2014 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-24677301

RESUMO

Herein, a novel anionic framework with primitive centered cubic (pcu) topology, [(CH3 )2 NH2 ]4 [(Zn4 dttz6 )Zn3 ]⋅15 DMF⋅4.5 H2 O, (IFMC-2; H3 dttz=4,5-di(1H-tetrazol-5-yl)-2H-1,2,3-triazole) was solvothermally isolated. A new example of a tetranuclear zinc cluster {Zn4 dttz6 } served as a secondary building unit in IFMC-2. Furthermore, the metal cluster was connected by Zn(II) ions to give rise to a 3D open microporous structure. The lanthanide(III)-loaded metal-organic framework (MOF) materials Ln(3+) @IFMC-2, were successfully prepared by using ion-exchange experiments owing to the anionic framework of IFMC-2. Moreover, the emission spectra of the as-prepared Ln(3+) @IFMC-2 were investigated, and the results suggested that IFMC-2 could be utilized as a potential luminescent probe toward different Ln(3+) ions. Additionally, the absorption ability of IFMC-2 toward ionic dyes was also performed. Cationic dyes can be absorbed, but not neutral and anionic dyes, thus indicating that IFMC-2 exhibits selective absorption toward cationic dyes. Furthermore, the cationic dyes can be gradually released in the presence of NaCl.

8.
Chemistry ; 20(13): 3589-94, 2014 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-24577888

RESUMO

A 2D, extremely stable, metal-organic framework (MOF), NENU-503, was successfully constructed. It displays highly selective and recyclable properties in detection of nitroaromatic explosives as a fluorescent sensor. This is the first MOF that can distinguish between nitroaromatic molecules with different numbers of NO2 groups.


Assuntos
Substâncias Explosivas/análise , Nitrocompostos/análise , Fluorescência , Estrutura Molecular , Nitrocompostos/química
9.
Inorg Chem ; 53(15): 8105-13, 2014 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-25052891

RESUMO

In this work, five novel 2D isostructural Cd(II)-lanthanide(III) heterometallic-organic frameworks [CdCl(L)Eu(x)Tb(y)(H2O)(DMA)](NO3)·3DMA (IFMC-36-Eu(x)Tb(y): x = 1, y = 0, IFMC-36-Eu; x = 0.6, y = 0.4, IFMC-36-Eu(0.6)Tb(0.4); x = 0.5, y = 0.5, IFMC-36-Eu(0.5)Tb(0.5); x = 0.4, y = 0.6, IFMC-36-Eu(0.4)Tb(0.6); x = 0, y = 1, IFMC-36-Tb; H3L is 4,4',4″-((2,2',2″-(nitrilotris(methylene))tris(1H-benzo[d]imidazole-2,1-diyl))tris(methylene))tribenzoic acid; IFMC = Institute of Functional Material Chemistry) have been successfully synthesized by taking advantage of different molar ratios of lanthanide(III) (Ln(III)) and metalloligands under solvothermal conditions. Further luminescent measurements indicate that IFMC-36-Eu(x)Tb(y) exhibits characteristic sharp emission bands of Eu(III) and Tb(III), and the intensities of red and green can be modulated correspondingly by tuning the ratios of Eu(III) and Tb(III). Particularly, the solvent-dependent luminescent behavior of IFMC-36-Eu shows a potential application in detection of small-molecule pollutant nitrobenzene by significant fluorescence quenching. Furthermore, IFMC-36-Eu displays preeminent anti-interference ability and could be used for sensing in the systems with complicated components. This is the first time that a d-f heterometallic-organic framework can be investigated as a chemical sensor for selective, sensitive, and recyclable detection of nitrobenzene.


Assuntos
Cádmio/química , Elementos da Série dos Lantanídeos/química , Nitrobenzenos/análise , Compostos Organometálicos/química , Ligantes , Medições Luminescentes , Nitrobenzenos/química , Compostos Organometálicos/síntese química
10.
Anal Methods ; 16(30): 5146-5153, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39011770

RESUMO

dsRNA is a product related impurity produced during the mRNA manufacturing process. The established immuno-based detection methods lack the flexibility and speed required to be applied throughout the manufacturing process. The RP-HPLC method developed outperforms these in terms of precision, broader detection range, LOD and LOQ, as well as in output variance. Using this method, dsRNA can be quantified in under 30 min for a single sample.


Assuntos
RNA de Cadeia Dupla , Vacinas de mRNA , Cromatografia Líquida de Alta Pressão/métodos , RNA de Cadeia Dupla/análise , RNA de Cadeia Dupla/química , Contaminação de Medicamentos/prevenção & controle , Limite de Detecção , Vacinas Sintéticas/química , Vacinas Sintéticas/análise , Espectrofotometria Ultravioleta/métodos , Humanos
11.
Int J Biol Macromol ; 278(Pt 1): 134363, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39089556

RESUMO

Acetyl-coenzyme A carboxylase (ACC) and diacylglycerol acyltransferase 2 (DGAT2) are recognized as potential therapeutic targets for nonalcoholic fatty liver disease (NAFLD). Inhibitors targeting ACC and DGAT2 have exhibited the capacity to reduce hepatic fat in individuals afflicted with NAFLD. However, there are no reports of dual inhibitors targeting ACC and DGAT2 for the treatment of NAFLD. Here, we aimed to identify potential dual inhibitors of ACC and DGAT2 using an integrated in silico approach. Machine learning-based virtual screening of commercial molecule databases yielded 395,729 hits, which were subsequently subjected to molecular docking aimed at both the ACC and DGAT2 binding sites. Based on the docking scores, nine compounds exhibited robust interactions with critical residues of both ACC and DGAT2, displaying favorable drug-like features. Molecular dynamics simulations (MDs) unveiled the substantial impact of these compounds on the conformational dynamics of the proteins. Furthermore, binding free energy assessments highlighted the notable binding affinities of specific compounds (V003-8107, G340-0503, Y200-1700, E999-1199, V003-6429, V025-4981, V006-1474, V025-0499, and V021-8916) to ACC and DGAT2. The compounds proposed in this study, identified using a multifaceted computational strategy, warrant experimental validation as potential dual inhibitors of ACC and DGAT2, with implications for the future development of novel drugs targeting NAFLD.


Assuntos
Acetil-CoA Carboxilase , Diacilglicerol O-Aciltransferase , Inibidores Enzimáticos , Aprendizado de Máquina , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Diacilglicerol O-Aciltransferase/antagonistas & inibidores , Diacilglicerol O-Aciltransferase/química , Diacilglicerol O-Aciltransferase/metabolismo , Acetil-CoA Carboxilase/antagonistas & inibidores , Acetil-CoA Carboxilase/química , Acetil-CoA Carboxilase/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Sítios de Ligação , Ligação Proteica , Avaliação Pré-Clínica de Medicamentos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico
12.
Plant Physiol Biochem ; 208: 108455, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38428157

RESUMO

'Zaosu' pear fruit is prone to yellowing of the surface and softening of the flesh after harvest. This work was performed to assess the influences of L-glutamate treatment on the quality of 'Zaosu' pears and elucidate the underlying mechanisms involved. Results demonstrated that L-glutamate immersion reduced ethylene release, respiratory intensity, weight loss, brightness (L*), redness (a*), yellowness (b*), and total coloration difference (ΔE); enhanced ascorbic acid, soluble solids, and soluble sugar contents; maintained chlorophyll content and flesh firmness of pears. L-glutamate also restrained the activities of neutral invertase and acid invertase, while enhancing sucrose phosphate synthetase and sucrose synthase activities to facilitate sucrose accumulation. The transcriptions of PbSGR1, PbSGR2, PbCHL, PbPPH, PbRCCR, and PbNYC were suppressed by L-glutamate, resulting in a deceleration of chlorophyll degradation. L-glutamate concurrently suppressed the transcription levels and enzymatic activities of polygalacturonases, pectin methylesterases, cellulase, and ß-glucosidase. It restrained polygalacturonic acid trans-eliminase and pectin methyl-trans-eliminase activities as well as inhibited the transcription levels of PbPL and Pbß-gal. Moreover, the gene transcriptions and enzymatic activities of arginine decarboxylase, ornithine decarboxylase, S-adenosine methionine decarboxylase, glutamate decarboxylase, γ-aminobutyric acid transaminase, glutamine synthetase along with the PbSPDS transcription was promoted by L-glutamate. L-glutamate also resulted in the down-regulation of PbPAO, PbDAO, PbSSADH, PbGDH, and PbGOGAT transcription levels, while enhancing γ-aminobutyric acid, glutamate, and pyruvate acid contents in pears. These findings suggest that L-glutamate immersion can effectively maintain the storage quality of 'Zaosu' pears via modulating key enzyme activities and gene transcriptions involved in sucrose, chlorophyll, cell wall, and polyamine metabolism.


Assuntos
Carboxiliases , Pyrus , Pyrus/genética , Pyrus/metabolismo , Sacarose/metabolismo , Ácido Glutâmico/metabolismo , Frutas/metabolismo , Clorofila/metabolismo , Parede Celular , Pectinas/metabolismo , Carboxiliases/metabolismo , Ácido gama-Aminobutírico/farmacologia , Poliaminas/metabolismo
13.
BMC Chem ; 18(1): 95, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38702788

RESUMO

Cholesteryl ester transfer protein (CETP) is a promising therapeutic target for cardiovascular diseases. It effectively lowers the low-density lipoprotein cholesterol levels and increases the high-density lipoprotein cholesterol levels in the human plasma. This study identified novel and highly potent CETP inhibitors using virtual screening techniques. Molecular docking and molecular dynamics (MD) simulations revealed the binding patterns of these inhibitors, with the top 50 compounds selected according to their predicted binding affinity. Protein-ligand interaction analyses were performed, leading to the selection of 26 compounds for further evaluation. A CETP inhibition assay confirmed the inhibitory activities of the selected compounds. The results of the MD simulations revealed the structural stability of the protein-ligand complexes, with the binding site remaining significantly unchanged, indicating that the five compounds (AK-968/40709303, AG-690/11820117, AO-081/41378586, AK-968/12713193, and AN-465/14952302) identified have the potential as active CETP inhibitors and are promising leads for drug development.

14.
Hortic Res ; 11(1): uhad263, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38304331

RESUMO

Free amino acids (FAAs) positively determine the tea quality, notably theanine (Thea), endowing umami taste of tea infusion, which is the profoundly prevalent research in albino tea genetic resources. Therefore, 339 tea accessions were collected to study FAAs level for deciphering its variation and accumulation mechanism. Interestingly, alanine (Ala) and Thea which had the highest diversity index (H') value among three varieties of Camellia sinensis (L.) O. Kuntze were significantly higher than wild relatives (P < 0.05). The intraspecific arginine (Arg) and glutamine (Gln) contents in C. sinensis var. assamica were significantly lower than sinensis and pubilimba varieties. Moreover, the importance of interdependencies operating across FAAs and chlorophyll levels were highlighted via the cell ultrastructure, metabolomics, and transcriptome analysis. We then determined that the association between phytochrome interacting factor 1 (CsPIF1) identified by weighted gene co-expression network analysis (WGCNA) and Thea content. Intriguingly, transient knock-down CsPIF1 expression increased Thea content in tea plant, and the function verification of CsPIF1 in Arabidopsis also indicated that CsPIF1 acts as a negative regulator of Thea content by mainly effecting the genes expression related to Thea biosynthesis, transport, and hydrolysis, especially glutamate synthase (CsGOGAT), which was validated to be associated with Thea content with a nonsynonymous SNP by Kompetitive Allele-Specific PCR (KASP). We also investigated the interspecific and geographical distribution of this SNP. Taken together, these results help us to understand and clarify the variation and profile of major FAAs in tea germplasms and promote efficient utilization in tea genetic improvement and breeding.

15.
Curr Res Food Sci ; 8: 100677, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38303998

RESUMO

Our prophase studies have manifested that the sweet triterpenoid glycoside from the leaves of Cyclocarya paliurus (CPST) effectively improved the disorders of glucolipid metabolism in vitro and in patients. The current purpose was to further detect its mechanisms involved. The results demonstrated that CPST could ameliorate high-fat diet (HFD)-induced insulin resistance (IR), which was linked to reducing HFD-induced mice's body weight, serum glucose (GLUO), triglyceride (TG), total cholesterol (T-CHO) and low-density lipoprotein cholesterol (LDL-C), lowering the area under the oral glucose tolerance curve and insulin tolerance, elevating the percentage of brown adipose, high-density lipoprotein cholesterol (HDL-C), reducing fat droplets of adipocytes in interscapular brown adipose tissue (iBAT) and cross-sectional area of adipocytes. Further studies manifested that CPST obviously downregulated TLR4, MyD88, NLRP3, ASC, caspase-1, cleased-caspase-1, IL-18, IL-1ß, TXNIP, and GSDMD protein expressions and p-NF-кB/NF-кB ratio in iBAT. These aforementioned findings demonstrated that CPST ameliorated HFD induced IR by regulating TLR4/NF-κB/NLRP3 signaling pathway, which in turn enhancing insulin sensitivity and glucose metabolism.

16.
Chemistry ; 19(34): 11279-86, 2013 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-23852886

RESUMO

A new family of heterometal-organic frameworks has been prepared by two synthesis strategies, in which IFMC-26 and IFMC-27 are constructed by self-assembly and IFMC-28 is obtained by stepwise synthesis based on the metalloligand (IFMC=Institute of Functional Material Chemistry). IFMC-26 is a (3,6)-connected net and IFMC-27 is a (4,8)-connected 3D framework. The metalloligands {Ni(H4 L)}(NO3 )2 are connected by binuclear lanthanide clusters giving rise to a 2D sheet structure in IFMC-28. Notably, IFMC-26-Eux Tby and IFMC-28-Eux Tby have been obtained by changing the molar ratios of raw materials. Owing to the porosity of IFMC-26, Tb(3+) @IFMC-26-Eu and Eu(3+) @IFMC-26-Tb are obtained by postencapsulating Tb(III) and Eu(III) ions into the pores, respectively. Tunable luminescence in metal-organic frameworks is achieved by the two kinds of doping methods. In particular, the quantum yields of heterometal-organic frameworks are apparently enhanced by postencapsulation of Ln(III) ions.


Assuntos
Compostos Organometálicos/química , Cristalografia por Raios X , Európio/química , Íons/química , Elementos da Série dos Lantanídeos/química , Conformação Molecular , Porosidade , Teoria Quântica , Espectrometria de Fluorescência , Térbio/química
17.
Dalton Trans ; 52(9): 2762-2769, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36749640

RESUMO

As a rising class of crystallographic organic polymers, covalent-organic frameworks (COFs) have high specific surface areas, ordered pore structures, and designability, which exhibit broad application prospects in the energy storage sector. However, their low electrical conductivity hinders their potential use in supercapacitors. To improve the electrical conductivity, we introduced carboxylated multi-walled carbon nanotubes to obtain a series of carbon nanotube@COF composites by a facile one-pot method, in which 2D TFA-COFs are in situ grown on the surface of carboxylated multi-walled carbon nanotubes. Among them, the CNT@TFA-COF-3 composite exhibits good crystallinity, regular pores, excellent stability and a specific surface area of 1034 m2 g-1. As expected, as a capacitive electrode material, the CNT@TFA-COF composite shows improved electrochemical performance. Notably, the value of specific capacitance of the CNT@TFA-COF-3 composite (338 F g-1) is about 8.5, 4.9, and 7.5 times higher than those of TFA-COFs, CNTs, and the CNT/TFA-COF physically mixed complex at a current density of 1.0 A g-1, respectively. Furthermore, the CNT@TFA-COF-3 supercapacitor exhibits long-term cycle chemical stability and splendid rate capability even after 7000 charge-discharge cycles. The successful preparation of the CNT@TFA-COF-3 composite can provide new ideas for the construction of new COF-based composites and the development of new materials for energy storage.

18.
Dalton Trans ; 52(18): 6138-6145, 2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37070778

RESUMO

Currently, the preparation of high-performance electrode materials is urgently needed for supercapacitors. As a new kind of organic porous material, covalent organic frameworks (COFs) with an ordered pore structure, a high specific surface area and designability, have shown great potential application value as electrode materials for supercapacitors. However, their potential application in supercapacitors is limited by the poor conductivity of COFs. Here, we in situ grew the highly crystalline triazine-based covalent organic framework DHTA-COF on a modified θ-Al2O3 substrate to obtain the composites Al2O3@DHTA-COFs. Some of the obtained Al2O3@DHTA-COF composites can maintain some degree of crystallinity, good stability and a vesicular structure. Compared to the precursors θ-Al2O3 and DHTA-COF, the 50%Al2O3@DHTA-COF composite has superior electrochemical properties as electrode materials for supercapacitors. Under the same conditions, the specific capacitance values of 50%Al2O3@DHTA-COF (261.5 F g-1 at 0.5 A g-1) are 6.2 and 9.6 times higher than the values of DHTA-COF and θ-Al2O3-CHO, respectively. Additionally, the 50%Al2O3@DHTA-COF electrode material exhibited long-term cycling stability even after 6000 charge-discharge cycles. The study can provide some reference for the development of COF-based composite materials for energy storage.

19.
Macromolecules ; 56(19): 7721-7728, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37841531

RESUMO

The study of aggregate formation and its controllable effect on luminescence behavior has a far-reaching influence in establishing a universal aggregation photophysical mechanism. In this paper, we obtained clusters with different extents of aggregation by heat-induced or light-triggered aggregation of a new polyurethane derivative (PUE). The controllable regulation of multicolor fluorescence of a single (nondoped) polymeric material is realized. The luminescence behavior of PUE varies with microscopic control of the aggregation structure. Compared with the powder state, the enhanced atom-atom and group-group interactions of PUE-gel effectively limit the nonradiative transitions in the excited state and result in a red-shift in emission. This work avoids complex organic synthesis and demonstrates a simple strategy to induce aggregation and regulate the emitting color of macromolecules, providing a template for developing new materials for multicolor fluorescence. In addition, a pattern was constructed with encryption, anticounterfeiting, and information transmission functions which provide a proof-of-concept demonstration of the practical potential of PUE as a smart material.

20.
Am J Chin Med ; 51(8): 2041-2075, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37957120

RESUMO

Cyclocarya paliurus (Batalin) Iljinskaja (C. paliurus) is a single species of Cyclocarya paliurus in Juglandaceae. It is a unique rare medicinal plant resource in China that is mainly distributed in the south of China. The leaves of C. paliurus, as a new food ingredient, are processed into tea products in daily life. Triterpenoids are the main active ingredient in C. paliurus. So far, 164 triterpenoid compounds have been isolated and identified from C. paliurus, which are included 3,4-seco-dammaranes, dammaranes, oleanane, ursane, lupinanes, taraxeranes, and norceanothanes. Modern pharmacological studies manifested that these ingredients have a wide range of pharmacological activities both in vitro and in vivo, such as reducing blood sugar, lowering blood lipids, and anti-tumor, anti-inflammatory, anti-oxidant, and other activities. In addition, current results indicate that the pharmacological mechanisms of triterpenoids were closely related to their chemical structure, molecular signaling pathways, and the expression of related proteins. In order to further study C. paliurus based on the current research situation, this review summarizes the prospect and systematic summary of the triterpenes of C. paliurus from the aspects of structural characteristics, quality control, biological activity, and the structure-activity relationship, which provide a reference for further research and application of the triterpenoids from C. paliurus in the field of functional food and medicine.


Assuntos
Antineoplásicos , Juglandaceae , Triterpenos , Extratos Vegetais/farmacologia , Relação Estrutura-Atividade , Triterpenos/química , Antineoplásicos/farmacologia , Juglandaceae/química , Controle de Qualidade , Folhas de Planta/química
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