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1.
Langmuir ; 40(33): 17613-17621, 2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39120008

RESUMEN

Dopamine (DA), a neurotransmitter, plays a crucial role in regulating motor functions and emotions and can serve as a marker for several diseases. In this study, we report a highly sensitive polydiacetylenes (PDA)-based dual-output sensor for dopamine detection in both solution and solid phases that was developed by modifying PDA liposomes with boronic acid groups at the termini. This sensor exploits the high affinity between the catechol residue of dopamine and the -B(OH)2 group of the PDA-based probe (PDA-PhBA) to form boronate ester bonds, causing a stress-induced blue-to-red color change along with a steady increase in fluorescence response at λmax 622 nm. The PDA-PhBA-based sensor displays high sensitivity toward dopamine with low limit of detection of 6.2 ppb in colorimetric analysis and 0.6 ppb in fluorimetric measurements, demonstrating its dual optical output ability. The sensor works well for adrenaline, another catecholamine, with similar efficacy. Its practical applicability was validated by the successful recovery of trace level dopamine in blood serum and real water samples. Additionally, immobilizing PDA-PhBA liposomes in sodium alginate produced PDA beads for the solid-phase detection of dopamine with an limit of detection (LOD) of 59 nM (9.0 ppb) in colorimetric detection using a smartphone for capturing images and ImageJ software for analysis.


Asunto(s)
Dopamina , Liposomas , Polímero Poliacetilénico , Liposomas/química , Dopamina/análisis , Dopamina/sangre , Polímero Poliacetilénico/química , Límite de Detección , Colorimetría/métodos , Polímeros/química , Poliinos/química , Soluciones
2.
Phytother Res ; 38(6): 2764-2799, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38522945

RESUMEN

Rheumatoid arthritis is a chronic autoimmune inflammatory disease characterized by immune response overexpression, causing pain and swelling in the synovial joints. This condition is caused by auto-reactive antibodies that attack self-antigens due to their incapacity to distinguish between self and foreign molecules. Dysregulated activity within numerous signalling and immunological pathways supports the disease's development and progression, elevating its complexity. While current treatments provide some alleviation, their effectiveness is accompanied by a variety of adverse effects that are inherent in conventional medications. As a result, there is a deep-rooted necessity to investigate alternate therapeutic strategies capable of neutralizing these disadvantages. Medicinal herbs display a variety of potent bioactive phytochemicals that are effective in the complementary management of disease, thus generating an enormous potency for the researchers to delve deep into the development of novel phytomedicine against autoimmune diseases, although additional evidence and understanding are required in terms of their efficacy and pharmacodynamic mechanisms. This literature-based review highlights the dysregulation of immune tolerance in rheumatoid arthritis, analyses the pathophysiology, elucidates relevant signalling pathways involved, evaluates present and future therapy options and underscores the therapeutic attributes of a diverse array of medicinal herbs in addressing this severe disease.


Asunto(s)
Artritis Reumatoide , Fitoterapia , Plantas Medicinales , Artritis Reumatoide/tratamiento farmacológico , Humanos , Plantas Medicinales/química , Animales , Fitoquímicos/farmacología , Fitoquímicos/uso terapéutico
3.
Small ; 19(46): e2303189, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37471172

RESUMEN

Two donor-acceptor type tetrathiafulvalene (TTF)-based covalent organic frameworks (COFs) are investigated as electrodes for symmetric supercapacitors in different electrolytes, to understand the charge storage and dynamics in 2D COFs. Till-date, most COFs are investigated as Faradic redox pseudocapacitors in aqueous electrolytes. For the first time, it is tried to enhance the electrochemical performance and stability of pristine COF-based supercapacitors by operating them in the non-Faradaic electrochemically double layer capacitance region. It is found that the charge storage mechanism of ionic liquid (IL) electrolyte based supercapacitors is dependent on the micropore size and surface charge density of the donor-acceptor COFs. The surface charge density alters due to the different electron acceptor building blocks, which in turn influences the dense packing of the IL near its pore. The micropores induce pore confinement of IL in the COFs by partial breaking of coulomb ordering and rearranging it. The combination of these two factors enhance the charge storage in the highly microporous COFs. The density functional theory calculations support the same. At 1 A g-1 , TTF-porphyrin COF provides capacitance of 42, 70, and 130 F g-1 in aqueous, organic, and IL electrolyte respectively. TTF-diamine COF shows a similar trend with 100 F g-1 capacitance in IL.

4.
Mol Pharm ; 20(10): 5226-5239, 2023 10 02.
Artículo en Inglés | MEDLINE | ID: mdl-37677085

RESUMEN

Multidrug salts represent more than one drug in a crystal lattice and thus could be used to deliver multiple drugs in a single dose. It showcases unique physicochemical properties in comparison to individual components, which could lead to improved efficacy and therapeutic synergism. This study presents the preparation and scale-up of sulfamethoxazole-piperazine salt, which has been thoroughly characterized by X-ray diffraction and thermal and spectroscopic analyses. A detailed mechanistic study investigates the impact of piperazine on the microenvironmental pH of the salt and its effect on the speciation profile, solubility, dissolution, and diffusion profile. Also, the improvement in the physicochemical properties of sulfamethoxazole due to the formation of salt was explored with lattice energy contributions. A greater ionization of sulfamethoxazole (due to pH changes contributed by piperazine) and lesser lattice energy of sulfamethoxazole-piperazine contributed to improved solubility, dissolution, and permeability. Moreover, the prepared salt addresses the stability issues of piperazine and exhibits good stability behavior under accelerated stability conditions. Due to the improvement of physicochemical properties, the sulfamethoxazole-piperazine salt demonstrates better pharmacokinetic parameters in comparison to sulfamethoxazole and provides a strong suggestion for the reduction of dose. The following study suggests that multidrug salts can concurrently enhance the physicochemical properties of drugs and present themselves as improved fixed-dose combinations.


Asunto(s)
Sales (Química) , Piperazina , Sales (Química)/química , Difracción de Rayos X , Solubilidad
5.
J Org Chem ; 88(21): 15358-15366, 2023 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-37871175

RESUMEN

A reagentless, catalyst-free, and sustainable methodology was developed for facile access to cyclic and acyclic ß-amino sulfones "on-water" using a microwave. A variety of aromatic and aliphatic amines undergo double aza-Michael addition on the surface of the water with water-insoluble divinyl sulfones upon microwave irradiation at 150 °C for 10 min to mostly afford solid cyclic ß-amino sulfones as easily separable products in excellent yields by simple filtration avoiding any workup steps. Thus, all atoms of the substrates are reflected in the product making it a 100% atom-efficient method. Both electron-rich and electron-deficient amines participated well in the reaction as well as good functional group tolerance was observed. The competitive experiments expectedly revealed faster reaction kinetics for electron-rich amines. The methodology was extended to acyclic ß-amino sulfones by interacting phenyl/ethyl vinyl sulfones with various amines in a similar manner. Expectedly, the method afforded very low environmental factors (in a range of 0.05-0.5) and a high Ecoscale score (up to 94). In an attempt toward sustainable development, this reagent-free, metal-free, organic solvent-free, cost-effective protocol is certainly a viable alternative to the available methods for ß-amino sulfones.

6.
J Org Chem ; 88(14): 10002-10013, 2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37418632

RESUMEN

A sustainable alternative to the century-old Duff reaction was developed by adopting a solid-phase mechanochemical route. A series of mono-formyl electron-rich arenes were prepared in high yields in silica as the solid reaction media using a combination of hexamethylenetetramine (HMTA) as the formyl source and a small amount of H2SO4 in a mixer mill. The use of toxic, costly, and low-boiling trifluoroacetic acid was avoided in the new mold of the mechanochemical Duff reaction. The mono-formyl phenols were obtained with exclusive ortho-selectivity, whereas unprecedented para-formylation was observed for other electron-rich aromatics. By controlling the stoichiometry of HMTA, the method offers easy access to di-formylated phenols as well. The scalability of the reaction was validated with selected substrates at the gram-scale level. In a case study, a mechanochemical tandem reaction was explored in the synthesis of a rhodol derivative. The solvent-free, metal-free mild method of formylation, with the absence of tedious work-up steps and shorter reaction times using an inexpensive mineral acid, is a sustainable alternative to the available methods for aromatic formylation.

7.
Analyst ; 147(15): 3604-3611, 2022 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-35837963

RESUMEN

Fluoride is present in groundwater and drinking water across the world and plays crucial roles in regulating oral health. Although a 0.7-1.2 ppm concentration of fluoride in water supplies is deemed optimal for enamel development and dental health, its higher concentration causes endemic fluorosis, acute gastric, urolithiasis, and kidney infection, making the detection of fluoride highly important. However, the standard methods of fluoride detection, such as potentiometric or ion-selective detection, require specific instruments and often pre-treatment before analysis and do not offer the scope for on-site detection. Herein, we report the development of a polydiacetylene (PDA) grafted poly(vinylidene fluoride) (PVDF) membrane for sensitive solid-phase detection of fluoride. The sensors were prepared by functionalizing PDA with the boronic acid functionality as the F- recognition unit and impregnating it on PVDF strips. Upon exposure to fluoride, the strips displayed a visible color change from blue to red. The solid-phase sensor showed selectivity against common anions and can detect F- ions as low as 0.11 ppm. The real sample analysis in water and toothpaste and validation by ion chromatography demonstrate its potential application as an efficient lab-on-membrane for fluoride ions.


Asunto(s)
Fluoruros , Polivinilos , Fluoruros/análisis , Flúor , Polímeros de Fluorocarbono , Polímero Poliacetilénico , Polivinilos/química
8.
Analyst ; 147(13): 2997-3006, 2022 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-35635289

RESUMEN

A coumarin coupled tetraphenylethylene based AIEgen (TPE-Lac) with an intense greenish-yellow emission has been synthesized and utilized for multipurpose sensing and imaging applications. TPE-Lac acts as a sensitive sensor for the detection of cyanide ions (CN-) with an immediate turn-off response in the presence of many other interfering cations and anions. The limit of detection (LOD) was as low as 33 nM, which is well below the permissible limit set by the World Health Organization (WHO). Cyanide detection in the solid phase was successfully demonstrated by drop-casting the solution of the TPE-Lac probe on TLC plates and measuring and analysing the fluorescence response by ImageJ analysis. TPE-Lac was further employed in the detection of explosive nitroaromatics in solution and solid phases. Also, TPE-Lac was found suitable as an imaging agent and could easily percolate into live H520 cells giving bright fluorescence from the intra-cellular region. Easy and cost-effective synthesis, fast response and low LODs are some of the advantages of this AIEgen over available molecular probes for the same purpose.


Asunto(s)
Cianuros , Sustancias Explosivas , Cumarinas , Cianuros/análisis , Colorantes Fluorescentes , Estilbenos
9.
Beilstein J Org Chem ; 18: 999-1008, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36051564

RESUMEN

A simple electrical mortar-pestle was used for the development of a green and facile mechanochemical route for the catalyst-free halogenation of phenols and anilines via liquid-assisted grinding using PEG-400 as the grinding auxiliary. A series of mono-, di-, and tri-halogenated phenols and anilines was synthesized in good to excellent yields within 10-15 min in a chemoselective manner by controlling the stoichiometry of N-halosuccinimides (NXS, X = Br, I, and Cl). It was observed that PEG-400 plays a key role in controlling the reactivity of the substrates and to afford better regioselectivity. Almost exclusive para-selectivity was observed for the aromatic substrates with free o- and p-positions for mono- and dihalogenations. As known, the decarboxylation (or desulfonation) was observed in the case of salicylic acids and anthranilic acids (or sulfanilic acids) leading to 2,4,6-trihalogenated products when 3 equiv of NXS was used. Simple instrumentation, metal-free approach, cost-effectiveness, atom economy, short reaction time, and mild reaction conditions are a few noticeable merits of this environmentally sustainable mechanochemical protocol.

10.
J Org Chem ; 86(20): 13911-13923, 2021 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-34398612

RESUMEN

The syntheses of dyes and fluorophores have significant commercial importance. In recent years, mechanochemistry has emerged as a green and sustainable alternative for the synthesis of conventional dyes, new fluorophores, and also synthetic modification of known dyes for their use as chemosensors. The dyestuffs based on BODIPYs, rhodamine, fluorescein, perylenedimides, coumarins, benzothiazoles, etc. were synthesized or derivatized by grinding or milling. The synopsis aims to pay key attention to their synthesis and the applications as chemosensors will be briefly covered.


Asunto(s)
Colorantes Fluorescentes , Fluoresceína , Rodaminas
11.
J Org Chem ; 84(17): 10764-10774, 2019 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-31373493

RESUMEN

A mechanochemical method for the preparation of synthetically useful 2-arylindoles is developed using Pd(II) as the catalyst in the absence of phosphine ligands in a ball-mill. The developed protocol is highly C-2 selective and tolerant of structural variations with electron-rich and electron-deficient substituents both in indoles and iodoarenes. Arylation is possible in both unprotected indoles and N-protected indoles with the electron-donating group with the former substrate being relatively slower to react and little less yielding. Indoles with a deactivated five-membered ring could also take part in the reaction with ease. The scalability of the reaction was demonstrated by conducting the reaction in the gram scale. In general, the reactions were achieved in a shorter time than the conventional methods.

12.
J Biol Chem ; 292(3): 936-944, 2017 01 20.
Artículo en Inglés | MEDLINE | ID: mdl-27956548

RESUMEN

Lipids are important nutrients that proliferating cells require to maintain energy homeostasis as well as to build plasma membranes for newly synthesized cells. Previously, we identified nutrient-sensing checkpoints that exist in the latter part of the G1 phase of the cell cycle that are dependent upon essential amino acids, Gln, and finally, a checkpoint mediated by mammalian target of rapamycin (mTOR), which integrates signals from both nutrients and growth factors. In this study, we have identified and temporally mapped a lipid-mediated G1 checkpoint. This checkpoint is located after the Gln checkpoint and before the mTOR-mediated cell cycle checkpoint. Intriguingly, clear cell renal cell carcinoma cells (ccRCC) have a dysregulated lipid-mediated checkpoint due in part to defective phosphatase and tensin homologue (PTEN). When deprived of lipids, instead of arresting in G1, these cells continue to cycle and utilize lipid droplets as a source of lipids. Lipid droplets have been known to maintain endoplasmic reticulum homeostasis and prevent cytotoxic endoplasmic reticulum stress in ccRCC. Dysregulation of the lipid-mediated checkpoint forces these cells to utilize lipid droplets, which could potentially lead to therapeutic opportunities that exploit this property of ccRCC.


Asunto(s)
Carcinoma de Células Renales/metabolismo , Membrana Celular/metabolismo , Puntos de Control de la Fase G1 del Ciclo Celular , Metabolismo de los Lípidos , Carcinoma de Células Renales/patología , Membrana Celular/patología , Estrés del Retículo Endoplásmico , Glutamina/metabolismo , Humanos , Neoplasias Renales , Células MCF-7 , Proteínas de Neoplasias/metabolismo , Fosfohidrolasa PTEN/metabolismo , Serina-Treonina Quinasas TOR/metabolismo
13.
J Nanosci Nanotechnol ; 18(12): 8142-8154, 2018 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-30189931

RESUMEN

Silica (SiO2) is the inevitable form of silicon owing to its high affinity for oxygen, existing as a geogenic element perpetrating multifarious health problems when bioavailable via anthropogenic activities. The hydrated form of silica viz. orthosilicic acid (H4SiO4) excessively displays grave toxicity, attributed to prolonged exposure and incessant H+ ions generating capacity inflicting pulmonary toxicity and renal toxicity silica. The diverse deleterious potency of silica highlights the desirability of selective and sensitive detection of toxic species (mainly orthosilicic acid) bioaccumulation in affected living human cells. In this paper we have reported, the design of water-dispersible turn-on fluorimetric sensing material for the detection of orthosilicic acid in the aqueous phase and in live cells. The sensing material was prepared by adsorbing a suitable rhodamine derivative (i.e., Rhodamine B hydrazide (Rh1)) on water dispersible TiO2 nanoparticles. The function of the sensing system, which is composed of Rh1 and TiO2 (Rh1@TiO2), is accredited to H+ ion (from orthosilicic acid) induced spirolactam ring-opening of the rhodamine derivative generating orange fluorescence and bright pink colouration. The sensing system was efficiently utilized for fluorimetric detection and imaging of orthosilicic acid accumulation in-vitro in human kidney cells (HK cells). To the best of our knowledge, this is the first time this sensing system (Rh1@TiO2) is reported for detection of toxic silica species accumulation in-vitro in human kidney cells. The advantages, such as good water dispersibility, the absence of organic solvents during fluorimetric studies, quick turn-on type signal transduction, low-level imaging, which are offered by the synthesized sensing material (Rh1@TiO2), make it a potential candidate to fabricate medical tool for early identification of silicainduced nephrotoxicity, which can help to reduce the burden and risk of chronic kidney disease development.


Asunto(s)
Hidrazinas , Nanopartículas , Rodaminas , Titanio , Humanos , Riñón/diagnóstico por imagen , Riñón/efectos de los fármacos , Nanopartículas/toxicidad , Rodaminas/toxicidad , Dióxido de Silicio/toxicidad , Agua
14.
Anal Chem ; 89(23): 12698-12704, 2017 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-29115126

RESUMEN

Methylmercury (CH3Hg+) is the common form of organic mercury and is more toxic than its inorganic or elemental forms. Mercury is emanated in the course of various natural events and human activities and converts to methylmercury by anaerobic organisms. CH3Hg+ are ingested by fish and subsequently bioaccumulated in their tissue and, eventually, enter the human diet, causing serious health issues. Therefore, selective and sensitive detection of bioaccumulated CH3Hg+ in fish samples is essential. Herein, the development of a simple, highly sensitive and selective aggregation-induced emission (AIE)-based turn-on probe for both inorganic mercury ions and organicmercury species is reported. The probe's function is based on mercury ion-promoted transmetalation reaction of aryl boronic acid. The probe, a tetraphenylethylene (TPE)-monoboronic acid (1), was successfully utilized for AIE-based fluorescence imaging study on methylmercury-contaminated live cells and zebrafish for the first time. Both Hg(II) and CH3Hg+ ensued a fast transmetalation of TPE-boronic acid causing drastic reduction in the solubility of the resulting product (TPE-HgCl/TPE-HgMe) in the working solvent system. At the dispersed phase, the aggregated form of TPE-mercury ions recovers planarity because of restricted rotational freedom promoting aggregation-induced emission. Simple design, cost-effective synthesis, high selectivity, inexpensive instrumentation, fast signal transduction, and low limit of detection (0.12 ppm) are some of the key merits of this analytical tool.


Asunto(s)
Mercurio/análisis , Compuestos de Metilmercurio/análisis , Microscopía Fluorescente/métodos , Animales , Ácidos Borónicos/síntesis química , Ácidos Borónicos/química , Ácidos Borónicos/toxicidad , Colorantes Fluorescentes/síntesis química , Colorantes Fluorescentes/química , Colorantes Fluorescentes/toxicidad , Células HEK293 , Humanos , Límite de Detección , Pez Cebra
15.
J Biol Chem ; 290(11): 6986-93, 2015 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-25632961

RESUMEN

AMP-activated protein kinase (AMPK), a critical sensor of energy sufficiency, acts as central metabolic switch in cell metabolism. Once activated by low energy status, AMPK phosphorylates key regulatory substrates and turns off anabolic biosynthetic pathways. In contrast, the mammalian/mechanistic target of rapamycin (mTOR) is active when there are sufficient nutrients for anabolic reactions. A critical factor regulating mTOR is phosphatidic acid (PA), a central metabolite of membrane lipid biosynthesis and the product of the phospholipase D (PLD)-catalyzed hydrolysis of phosphatidylcholine. PLD is a downstream target of the GTPase Rheb, which is turned off in response to AMPK via the tuberous sclerosis complex. Although many studies have linked AMPK with mTOR, very little is known about the connection between AMPK and PLD. In this report, we provide evidence for reciprocal regulation of PLD by AMPK and regulation of AMPK by PLD and PA. Suppression of AMPK activity led to an increase in PLD activity, and conversely, activation of AMPK suppressed PLD activity. Suppression of PLD activity resulted in elevated AMPK activity. Exogenously supplied PA abolished the inhibitory effects of elevated AMPK activity on mTOR signaling. In contrast, exogenously supplied PA could not overcome the effect AMPK activation if either mTOR or Raptor was suppressed, indicating that the inhibitory effects of PLD and PA on AMPK activity are mediated by mTOR. These data suggest a reciprocal feedback mechanism involving AMPK and the PLD/mTOR signaling node in cancer cells with therapeutic implications.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Neoplasias/enzimología , Fosfolipasa D/metabolismo , Línea Celular Tumoral , Activación Enzimática , Humanos , Diana Mecanicista del Complejo 1 de la Rapamicina , Complejos Multiproteicos/metabolismo , Neoplasias/metabolismo , Ácidos Fosfatidicos/metabolismo , Serina-Treonina Quinasas TOR/metabolismo
16.
Anal Chem ; 87(21): 10871-7, 2015 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-26458016

RESUMEN

Herein, a sensitive fluorimetric assay for dissolved carbon dioxide (dCO2) was developed by using ion-induced self-assembly of a tetraphenylethylene derivative by taking advantage of its aggregation induced emission property. Chitosan, a commercially available polymer having amine functionality was utilized for the ion induced assay. In the presence of dCO2, the amine groups in the chitosan get protonated to convert neutral chitosan to a positively charged species, triggering negatively charged tetraphenylethene derivative (probe 1) to aggregate with it by electrostatic interaction. The aggregation causes intense blue fluorescence output from the system. The extent of the aggregation is reliant on the charge density of polymer, which is equivalent to dCO2 concentration. A linear relationship from 5 to 50 µM of dCO2, with a limit of detection of 5 × 10(-6) M (0.00127 hPa) was obtained. This is the first report for detecting dCO2 utilizing the AIE property.


Asunto(s)
Dióxido de Carbono/análisis , Etilenos/química , Espectrometría de Fluorescencia/métodos , Solubilidad , Temperatura
17.
J Hazard Mater ; 469: 133998, 2024 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-38493622

RESUMEN

Mercury is a highly hazardous element due to its profound toxicity and wide abundance in the environment. Despite the availability of various fluorimetric detection tools for Hg2+, including organic fluorophores and aptasensors, they often suffer from shortcomings like the utilization of expensive chemicals and toxic organic solvents, multi-step synthesis, sometimes with poor selectivity and low sensitivity. Whereas, biomass-derived fluorophores, such as carbon dots (CDs), present themselves as cost-effective and environmentally benign alternatives that exhibit comparable efficacy. Herein, we report a reaction-driven sensing assembly based on CDs, MnO2 nanosheets, and hydroquinone monothiocarbonate (HQTC) for the detection of Hg2+ ions, which relies on the formation of a CDs-MnO2 FRET-conjugate, resulting in the quenching of the intrinsic fluorescence of CDs. In a pseudochemodosimetric approach, the thiophilic nature of mercury was utilized for in-situ generation of the reducing species, hydroquinone from HQTC, resulting in the reduction of MnO2 nanosheets, the release of fluorescent CDs back to the solution. The low limit of detection (LOD) was achieved as 2 ppb (0.01 µM). The probe worked efficiently in real water samples like sea, river with good recovery of spiked Hg2+ and in some Indian ayurvedic medicines as well. Furthermore, solid-phase detection with sodium alginate beads demonstrated the ability of this cost-effective sensing assembly for onsite detection of Hg2+ ions.

18.
J Nutr Biochem ; 129: 109622, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38490348

RESUMEN

Globally, neurodegeneration and cerebrovascular disease are common and growing causes of morbidity and mortality. Pathophysiology of this group of diseases encompasses various factors from oxidative stress to gut microbial dysbiosis. The study of the etiology and mechanisms of oxidative stress as well as gut dysbiosis-induced neurodegeneration in Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis, autism spectrum disorder, and Huntington's disease has recently received a lot of attention. Numerous studies lend credence to the notion that changes in the intestinal microbiota and enteric neuroimmune system have an impact on the initiation and severity of these diseases. The prebiotic role of polyphenols can influence the makeup of the gut microbiota in neurodegenerative disorders by modulating intracellular signalling pathways. Metabolites of polyphenols function directly as neurotransmitters by crossing the blood-brain barrier or indirectly via influencing the cerebrovascular system. This assessment aims to bring forth an interlink between the consumption of polyphenols biotransformed by gut microbiota which in turn modulate the gut microbial diversity and biochemical changes in the brain. This systematic review will further augment research towards the association of dietary polyphenols in the management of gut dysbiosis-associated neurodegenerative diseases.


Asunto(s)
Disbiosis , Microbioma Gastrointestinal , Enfermedades Neurodegenerativas , Polifenoles , Polifenoles/farmacología , Disbiosis/tratamiento farmacológico , Microbioma Gastrointestinal/efectos de los fármacos , Humanos , Enfermedades Neurodegenerativas/tratamiento farmacológico , Animales , Estrés Oxidativo/efectos de los fármacos , Fitoterapia , Prebióticos , Dieta
19.
Adv Mater ; 36(26): e2314056, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38618981

RESUMEN

A thorough and quantitative understanding of the fate of excitons in covalent-organic frameworks (COFs) after photoexcitation is essential for their augmented optoelectronic and photocatalytic applications via precise structure tuning. The synthesis of a library of COFs having identical chemical backbone with impeded conjugation, but varied morphology and surface topography to study the effect of these physical properties on the photophysics of the materials is herein reported. The variation of crystallite size and surface topography substantified different aggregation pattern in the COFs, which leads to disparities in their photoexcitation and relaxation properties. Depending on aggregation, an inverse correlation between bulk luminescence decay time and exciton binding energy of the materials is perceived. Further transient absorption spectroscopic analysis confirms the presence of highly localized, immobile, Frenkel excitons (of diameter 0.3-0.5 nm) via an absence of annihilation at high density, most likely induced by structural torsion of the COF skeletons, which in turn preferentially relaxes via long-lived (nanosecond to microsecond) excimer formation (in femtosecond scale) over direct emission. These insights underpin the importance of structural and topological design of COFs for their targeted use in photocatalysis.

20.
Chem Commun (Camb) ; 59(25): 3627-3654, 2023 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-36861263

RESUMEN

There is an urgent need for cleaner production processes for chemicals. An efficient and promising alternative for such reactions is heterogeneous photocatalysis, which works on the principle of converting (visible) light, including solar energy, into chemical energy. To that end, properly designed semiconductor based photocatalysts are necessary to trigger the photocatalytic reactions. Many commonly used photocatalysts have too large bandgaps (3-3.4 eV) to use visible light and a too low surface area for efficient production. Metal-organic frameworks (MOFs) have emerged as an encouraging class of materials for photocatalytic applications due to their (i) large surface area and porosity that facilitate adsorption towards chemicals, (ii) tunable crystallinity and optical and electronic properties for efficient light absorption in the visible region, (iii) tunable composition and functionality that make them versatile photocatalysts for a wide range of reactions, and (iv) facile development of composites with other semiconductors to produce Z-scheme heterojunctions that can effectively suppress the recombination of photogenerated charges. Ongoing research has started focusing on the judicious construction of Z-scheme heterojunctions in MOFs, to mimic natural photosynthesis, such that the MOF photocatalysts have higher light harvesting capacity, spatially separated reductive and oxidative active sites, and well-preserved redox ability. This review provides a concise compilation of the recent progress in the development and applications of MOF-based Z-scheme photocatalysts, their advanced characterization, and future perspectives for further advancements.

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