Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 98
Filtrar
1.
Environ Res ; 220: 115153, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36574802

RESUMO

This study reports a versatile process for the fabrication of a microporous heterogeneous palladium nanocatalyst on a novel spherical, biodegradable, and chemically/physically resistant catalyst support consisting of chitosan (CS) and cigarette waste-derived activated carbon (CAC). The physicochemical properties of the microporous Pd-CS-CAC nanocatalyst developed were successfully determined by FTIR, XRD, FE-SEM, TEM, BET, and EDS techniques. TEM studies showed that the average particle size of the synthesized Pd NPs was about 30 nm. The catalytic prowess of microporous Pd-CS-CAC was evaluated in the reduction/decolorization of various nitroarenes (2-nitroaniline (2-NA), 4-nitroaniline (4-NA), 4-nitrophenol (4-NP), and 4-nitro-o-phenylenediamine (4-NPD)) and organic dyes (methyl red (MR), methyl orange (MO), methylene blue (MB), congo red (CR), and rhodamine B (RhB)) in an aqueous medium in the presence of NaBH4 as the reducing agent at room temperature. The catalytic activities were studied by UV-Vis absorption spectroscopy of the supernatant at regular time intervals. The short reaction times, mild reaction conditions, high efficiency (100% conversion), easy separation, and excellent chemical stability of the catalyst due to its heterogeneity and reusability are the advantages of this method. The results of the tests showed that reduction/decolorization reactions were successfully carried out within 10-140 s due to the good catalytic ability of Pd-CS-CAC. Moreover, Pd-CS-CAC was reused for 5 consecutive times with no loss of the initial shape, size, and morphology, confirming that it was a sustainable and robust nanocatalyst.


Assuntos
Quitosana , Paládio , Paládio/química , Quitosana/química , Corantes/química , Vermelho Congo/química , Extratos Vegetais/química , Catálise
2.
Crit Rev Food Sci Nutr ; : 1-26, 2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36384372

RESUMO

Extensive use of α-pinene in cosmetics, and medicine, especially for its antioxidant/antibacterial, and anti-cancer properties, and also as a flavoring agent, has made it a versatile product. α-Pinene (one of the two pinene isomers) is the most abundant terpene in nature. When extracting α-pinene from plants and, to a lesser extent, fruits, given that its purity is essential, purification methods should also be used as described in this study. Also, an attempt has been made to describe the extraction techniques of α-pinene, carried out by conventional and novel methods. Some disadvantages of conventional methods (such as hydrodistillation or solvent extraction) are being time consuming, low capacity per batch and being labor intensive and the requirement of trained operators. Most novel methods, such as supercritical fluid extraction and microwave-assisted extraction, can reduce the extraction time, cost, and energy compared to conventional methods, and, in fact, the extraction and preservation efficiency of α-pinene in these methods is higher than conventional methods. Although the above-mentioned extraction methods are effective, they still require rather long extraction times. In fact, advanced methods such as green and solvent-free ultrasonic-microwave-assisted extraction are much more efficient than microwave-assisted extraction and ultrasound-assisted extraction because the extraction efficiency and separation of α-pinene in these methods are higher; furthermore, no solvent consumption and maximum extraction efficiency are some crucial advantages of these techniques. However, the application of some novel methods, such as ultrasound-assisted extraction, in industry scale is still problematic because of their intricate design data.

3.
Crit Rev Food Sci Nutr ; 61(19): 3160-3196, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32715740

RESUMO

The demand for food and beverage markets has increased as a result of population increase and in view of health awareness. The quality of products from food processing industry has to be improved economically by incorporating greener methodologies that enhances the safety and shelf life via the enzymes application while maintaining the essential nutritional qualities. The utilization of enzymes is rendered more favorable in industrial practices via the modification of their characteristics as attested by studies on enzyme immobilization pertaining to different stages of food and beverage processing; these studies have enhanced the catalytic activity, stability of enzymes and lowered the overall cost. However, the harsh conditions of industrial processes continue to increase the propensity of enzyme destabilization thus shortening their industrial lifespan namely enzyme leaching, recoverability, uncontrollable orientation and the lack of a general procedure. Innovative studies have strived to provide new tools and materials for the development of systems offering new possibilities for industrial applications of enzymes. Herein, an effort has been made to present up-to-date developments on enzyme immobilization and current challenges in the food and beverage industries in terms of enhancing the enzyme stability.


Assuntos
Enzimas Imobilizadas , Indústria Alimentícia , Estabilidade Enzimática , Enzimas Imobilizadas/metabolismo , Tecnologia
4.
Chem Rec ; 20(11): 1338-1393, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32990405

RESUMO

One of the most abundant wastes from all around the world is nutrient resources. Among them, fruits, their extracts, and residues comprise a major portion, which contain many valuable components that get lost during disposal or become burden on the shrinking landfills. These concerns are addressed by seeking sustainable processing methods that would have a minimal environmental impact. The crops contain renewable chemicals which are useful for catalysis, wastewater treatment, or preparation of nanomaterials; there has been an upsurge for the industrial applications of (nano)materials as their environmental and catalytic appliances is a fascinating subject to design cheaper and safer catalytic systems. Due to the excellent chemical properties of the fruit extracts, they have garnered attention as cost-effective catalysts and support materials. This review focuses on the preparation of (nano)materials and their catalytic and environmental applications and highlights the potential appliances and industrial benefits derived from these low-cost renewable and sustainable greener sources thus essentially converting waste into wealth.


Assuntos
Sucos de Frutas e Vegetais , Frutas/química , Nanoestruturas/química , Catálise , Técnicas de Química Sintética/métodos , Recuperação e Remediação Ambiental/métodos , Compostos Orgânicos/síntese química
5.
Chem Soc Rev ; 48(18): 4791-4822, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31460520

RESUMO

The waste-to-wealth concept aims to promote a future sustainable lifestyle where waste valorization is seen not only for its intrinsic benefits to the environment but also to develop new technologies, livelihoods and jobs. Based on the concept of waste valorization and circular economy, this review aims to provide an overview of present trends and future potential in the conversion of residues from different food sectors into valuable bio(nano)materials.


Assuntos
Nanoestruturas/química , Eliminação de Resíduos
6.
Molecules ; 25(10)2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32414061

RESUMO

Chitosan has been used for biomedical applications in recent years, primarily because of its biocompatibility. A chitosan membrane with a 30 µm thickness was prepared and investigated for its surface modification using methane ions. Methane ions were implanted into the chitosan membrane using a Kaufman ion source; bombardment was accomplished using three accelerating voltages of ion beams-30, 55, and 80 keV. The influence of the ion bombardment on morphology, crystallinity, and hydrophilicity was investigated. Attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy analysis showed that a triplet bond appeared after the implantation of methane ions (acceleration voltage: 80 keV), culminating in the creation of a more amorphous membrane structure. The analyses of atomic force microscopy (AFM) images showed that, with the increase in bombardment energy, the roughness of the surface changed. These results revealed that ion bombardment improved the hydrophilicity of the membranes and the water fluxes of chitosan membranes altered after methane ion bombardment.


Assuntos
Quitosana/química , Membranas Artificiais , Metano/química , Interações Hidrofóbicas e Hidrofílicas , Microscopia de Força Atômica , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Chem Rec ; 19(12): 2436-2479, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31021524

RESUMO

Among different metallic nanoparticles, sliver nanoparticles (Ag NPs) are one of the most essential and fascinating nanomaterials. Importantly, among the metal based nanoparticles, Ag NPs play a key role in various fields such as biomedicine, biosensors, catalysis, pharmaceuticals, nanoscience and nanotechnology, particularly in nanomedicine. A main concern about the chemical synthesis of Ag NPs is the production of hazardous chemicals and toxic wastes. To overcome this problem, many research studies have been carried out on the green synthesis of Ag NPs using green sources such as plant extracts, microorganisms and some biopolymers without formation of hazardous wastes. Among green sources, plants could be remarkably valuable to exploring the biosynthesis of Ag NPs. In this review, the green synthesis of Ag-based nanocatalysts such as Ag NPs, AgPd NPs, Au-Ag NPs, Ag/AgPd NPs, Ag/Cu NPs, Ag@AgCl NPs, Au-Ag@AgCl nanocomposite, Ag-Cr-AC nanocomposite and Ag NPs immobilized on various supports such as Natrolite zeolite, bone, ZnO, seashell, hazelnut shell, almond shell, SnO2 , perlite, ZrO2 , TiO2 , α-Al2 O3 , CeO2 , reduced graphene oxide (rGO), h-Fe2 O3 @SiO2 , and Fe3 O4 using numerous plant extracts as reducing and stabilizing agents in the absence of hazardous surfactant and capping agents has been focused. This work describes the state of the art and future challenges in the biosynthesis of Ag-based nanocatalysts. The fact about the application of living plants in metal nanoparticle (MNPs) industry is that it is a more economical and efficient biosynthesis biosynthetic procedure. In addition, the catalytic activities of the synthesized, Ag-based recyclable nanocatalysts using various plant extracts in several chemical reactions such as oxidation, reduction, coupling, cycloaddition, cyanation, epoxidation, hydration, degradation and hydrogenation reactions have bben extensively discussed.


Assuntos
Antibacterianos/biossíntese , Química Verde/métodos , Nanopartículas Metálicas/química , Plantas/química , Prata/química , Antibacterianos/química , Benzimidazóis/síntese química , Benzimidazóis/química , Catálise , Extratos Vegetais/química , Plantas/metabolismo , Quinolinas/síntese química , Quinolinas/química , Dióxido de Silício/química
8.
Chem Rec ; 19(2-3): 601-643, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30230690

RESUMO

Copper nanoparticles (NPs) are one of the most commercialized nanomaterials. From the standpoint of nanotechnology copper-based nanostructured materials have many applications in biological process, folk medicine, electronics, and industrial fields. With growing concern regarding the energy crisis and problems of chemical and physical procedures to prepare the metal nanoparticles, efforts for alternative traditional chemistry attracted particular considerations. A widespread of researches have studied on biological methods which do not generate hazardous waste and therefore, don't need the purification processes. Plants could be remarkably valuable to exploring the biogenic synthesis of metal nanoparticles. The aim of this review is to provide further insight in to connections between plant extracts and synthesis of copper NPs. The utilization of living plants for biosynthesis of metal nanoparticles (MNPs) is a cost-effective and eco-friendly procedure. To date, the obtained results demonstrated several aspects of the plant physiology and their relations to nanoparticle synthesis. This work describes the state of the art and future challenges in green synthesis of copper NPs. This review has proven recent elevation in the green synthesis of Cu NPs, CuO NPs, Cu2 O NPs, CuS NPs, CuAl2 O4 and immobilized copper nanoparticles on the numerous supports such as Natrolite, bentonite, perlite, ZnO, MgO, MnO2 , reduced graphene oxide (RGO), and Fe3 O4 by a wide range of plant extracts. Therefore, detailed description of green synthesis and stabilizing agents concerning copper nanoparticles using these green sources is presented. Also, the catalytic activities of synthesized Cu-based recyclable nanocatalysts using various plant extracts in several chemical reactions such as oxidation, reduction, hydration, cyanation, cycloaddition, and coupling reactions were consciously investigated.


Assuntos
Cobre/química , Nanopartículas Metálicas/química , Extratos Vegetais/química , Catálise , Química Verde , Plantas/química
9.
Int J Mol Sci ; 20(13)2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31284439

RESUMO

Radio frequency plasma is one of the means to modify the polymer surface namely in the activation of polypropylene membranes (PPM) with O2 plasma. Activated membranes were deposited with TiO2 nanoparticles by the dip coating method and the bare sample and modified sample (PPM5-TiO2) were irradiated by UV lamps for 20-120 min. Characterization techniques such as X-ray diffraction (XRD), Attenuated total reflection technique- Fourier transform infrared spectroscopy (ATR-FTIR), Thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM) and water contact angle (WCA) measurements were applied to study the alteration of ensuing membrane surface properties which shows the nanoparticles on the sample surface including the presence of Ti on PPM. The WCA decreased from 135° (PPM) to 90° (PPM5-TiO2) and after UV irradiation, the WCA of PPM5-TiO2 diminished from 90° to 40°.


Assuntos
Membranas Artificiais , Nanopartículas/química , Oxigênio/química , Gases em Plasma/química , Polipropilenos/química , Titânio/química , Espectroscopia Fotoeletrônica , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termogravimetria , Água/química , Molhabilidade , Difração de Raios X
10.
Chem Rec ; 18(10): 1409-1473, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29537731

RESUMO

A3 coupling is one of the few transition-metal catalyzed carbon-carbon bond forming reactions that have been established as a most direct, efficient and atom-economical synthetic approach to afford propargylamine derivatives using various catalysts. A large number of nanosized heterogeneous catalysts for three-component coupling reactions between an aldehyde, an amine, and a terminal alkyne have been popularly introduced as an A3 coupling in the last decade. The coupling product has found a broad application as a key intermediate for a variety of heterocyclic useful compounds and numerous biologically active molecules such as ß-lactams, conformationally restricted peptides, isosteres, herbicides, fungicides, indolizines, pyrroles, quinolines and therapeutic drug molecules. This review aims to give an overview of the current progress made towards the preparation and application of various nanocatalysts-catalyzed A3 coupling transformations for the synthesis of propargylamines from 2007 to 2017. Several nanocatalysts based on metal and metal oxide nanoparticles (NPs) such as copper, gold, silver, iron, nickel, cobalt and zinc have successfully been employed in A3 coupling reactions. Besides, core-shells NPs, polymers, complexes, graphenes, metal-organic frameworks and ionic liquids have also been used in these reactions. Abundant examples have been given in this area. Different aspects of the reactions, disparate methods of preparation of nanocatalysts, characterization and their reusability have been perused.

11.
Chem Rec ; 18(2): 165-229, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28745452

RESUMO

The carbon-carbon and carbon-heteroatom bonds catalytic formation is among the most significant reactions in organic synthesis which extensively applied for synthesis of natural products, heterocycles, dendrimers, biologically active molecules and useful compounds. This review provides the latest advances in the preparation of graphene supported metal nanoparticles and their application in the catalytic formation of both carbon-carbon (C-C) and carbon-heteroatom (C-X) bonds including the Suzuki, Heck, Hiyama, Ullmann, Buchwald and Sonogashira coupling reactions. Numerous examples are given concerning the use of these catalysts in C-C and C-X coupling reactions along with the reliable and simple preparation methods of these catalysts, their characterization and catalytic properties and also the recycling possibilities.

12.
Molecules ; 23(10)2018 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-30287773

RESUMO

Carbon‒carbon (C‒C) and carbon‒heteroatom (C‒X) bonds that form via transition-metal-catalyzed processes have been extensively used in the organic synthesis and preparation of natural products and important compounds such as heterocycles, biologically active molecules, and dendrimers. Among the most significant catalysts, magnetic nanoparticles-supported palladium complexes are very effective, versatile, and heterogeneous catalysts for a wide range of C‒C and C‒X coupling reactions due to their reusability, thermal stability, and excellent catalytic performance. In this review, recent advances to develop magnetic nanoparticles supported palladium complexes, including their preparation, characterization, catalytic application, and reusability in the formation of both C‒C and C‒X bonds, by authors such as Sonogashira, Heck, Suzuki‒Miyaura, and Stille, and a few examples concerning N-arylation, S-arylation, and Csp2-P coupling reactions are discussed.


Assuntos
Carbono/química , Catálise , Complexos de Coordenação/química , Nanopartículas de Magnetita/química , Técnicas de Química Sintética , Dendrímeros/química , Estrutura Molecular , Paládio/química
13.
Carbohydr Polym ; 343: 122443, 2024 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-39174086

RESUMO

Nature-inspired chitosan (CS) materials show a high potential for the design/fabrication of sustainable heterogeneous (nano)materials with extraordinary structural/physical features, such as superior biodegradability/biocompatibility, simplicity of chemical modification, environmental safety, high availability, cost-effectiveness, high electrochemical activity, good film-forming ability, and antioxidant, antimicrobial/antibacterial, and anticoagulant activities. Industrialization and growth of industrial wastes or by-products induce an increasing demand for the development of clean, low-cost, and renewable natural systems to minimize or eliminate the utilization of environmentally toxic compounds. The preparation of novel heterogeneous functionalized polysaccharide-inspired bio(nano)materials via chemical modifications of natural CS to improve its physicochemical/biochemical properties has recently become tremendously attractive for many researchers. The most abundantly available and cost-effective functionalized CS-inspired (nano)materials are considerably valuable in terms of the economic aspects of production of (nano)catalysts, (nano)hydrogels, (nano)composite/blend membranes, and thus their commercialization. In this respect, the preparation of functionalized CS-inspired (nano)materials containing -SO3H groups has been represented as a valid alternative to the homogenous unmodified biomaterials for various applications. Sulfonated derivatives of CS-inspired (nano)materials may possess huge surface areas, catalytic activity, adsorption, and biological/biomedical properties. This review article is aimed at the investigation of different methods and potential applications of sulfonated CS-inspired (nano)materials in catalysis, fuel cells, adsorption of ions, membranes, and biological applications.

14.
Heliyon ; 10(10): e31058, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38803939

RESUMO

Loading drugs in drug delivery systems can increase their retention time and control their release within the knee cavity. Hence, we aimed to improve the therapeutic efficacy of celecoxib and kartogenin (KGN) through their loading in chitosan nanoparticles (CS NPs). Celecoxib-loaded nanoparticles (CNPs) and KGN-loaded nanoparticles (K-CS NPs) were prepared using the absorption method and covalent attachment, respectively, through an ionic gelation process. The morphology, particle size, zeta potential, polydispersity index (PDI), conjugation efficiency (CE), encapsulation efficiency (EE), the in vitro release of the drug from NPs, as well as MTT and hemolysis assays, were evaluated. Then, the IL-1ß-stimulated chondrocytes were treated with CNPs and K-CS NPs, individually or in combination, to explore their potential chondroprotective and anti-inflammatory effects. CNPs and K-CS NPs showed sizes of 352.6 ± 22.5 and 232.7 ± 4.5 nm, respectively, suitable for intra-articular (IA) injection. Based on the hemolysis results, both NPs exhibited good hemocompatibility within the studied range. Results showed that treating IL-1ß-pretreated chondrocytes with CNPs or K-CS NPs remarkably limited the negative effects of IL-1ß, especially when both types of NPs were used together. Therefore, injecting these two NPs into the knee cavity may improve drug bioavailability, rapidly suppress inflammation and pain, and promote cartilage regeneration. Meanwhile, for the first time, the study investigated the effect of the simultaneous use of celecoxib and KGN to treat osteoarthritis (OA).

15.
Int J Biol Macromol ; 278(Pt 3): 134747, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39151844

RESUMO

Today, with the growth of the human population, industrial activities have also increased. Different industries such as painting, cosmetics, leather, etc. have broadly developed, and as a result, they also produce a lot of pollutants. These pollutants can enter the environment and pollute water, air, and soil. Organic dyes, nitro compounds, drug residues, pesticides and herbicides are pollutants that should be removed from the environment. Natural polymers or biopolymers are important types of organic materials that are broadly applied for different applications. Among them, polysaccharides and lignin, which are two types of biopolymers, have attracted much consideration owing to their advantages such as biocompatibility, environmental friendly, safety, availability, etc. Polysaccharides include cellulose, gum, starch, alginate (Alg), chitin, and chitosan (CS). On the other hand, bentonite is one of the types of clays, which owing to their properties like large specific surface area, adsorption performance, naturally available, etc., have drawn the interest of many researchers. As a result, the synthesis of a composite including polysaccharide/lignin and bentonite can be very efficient for different applications, especially environmental ones. In this review, we instigated the preparation of these composites as well as the removal performance of them. In fact, we reported recent advancements in the synthesis of lignin- and polysaccharide-bentonite composites for the removal of diverse kinds of contaminants like organic dyes, nitro compounds, and hazardous materials.


Assuntos
Bentonita , Lignina , Polissacarídeos , Purificação da Água , Bentonita/química , Lignina/química , Purificação da Água/métodos , Polissacarídeos/química , Poluentes Químicos da Água/química
16.
Int J Biol Macromol ; 269(Pt 2): 131956, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38692526

RESUMO

Water sources have become extremely scarce and contaminated by organic and inorganic industrial and agricultural pollutants as well as household wastes. Poisoning water resources by dyes and metals is a problem because contaminated water can leak into subsurface and surface sources, causing serious contamination and health problems. Therefore, developing wastewater treatment technologies is valuable. Today, hydrogels have attracted considerable attention owing to their broad applications. Hydrogels are polymeric network compositions with significant water-imbibing capacity. Hydrogels have potential applications in diverse fields such as biomedical, personal care products, pharmaceuticals, cosmetics, and biosensors. They can be prepared by using natural (biopolymers) and synthetic polymers. Synthetic polymer-based hydrogels obtained from petrochemicals are not environmentally benign; thus, abundant plant-based polysaccharides are found as more suitable compounds for making biodegradable hydrogels. Polysaccharides with many advantages such as non-toxicity, biodegradability, availability, inexpensiveness, etc. are widely employed for the preparation of environmentally friendly hydrogels. Polysaccharides-based hydrogels containing chitin, chitosan, gum, starch (St), etc. are employed to remove pollutants, metals, and dyes. Among these, St has attracted a lot of attention. St can be mixed with other compounds to make hydrogels, which remove dyes and metal ions to variable degrees of efficiency. Although St has numerous advantages, it suffers from drawbacks such as low stability, low water solubility, and fast degradability in water which limit its application as an environmental adsorbent. As an effective way to overcome these weaknesses, various modification approaches to form starch-based hydrogels (SBHs) employing different compounds have been reported. The preparation methods and applications of SBH adsorbents in organic dyes, hazardous materials, and toxic ions elimination from water resources have been comprehensively discussed in this review.


Assuntos
Hidrogéis , Amido , Hidrogéis/química , Amido/química , Purificação da Água/métodos , Poluentes Químicos da Água/química , Adsorção , Corantes/química , Biodegradação Ambiental
17.
Adv Colloid Interface Sci ; 328: 103158, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38718629

RESUMO

The preparation/application of heterogeneous (nano)materials from natural resources has currently become increasingly fascinating for researchers. Cellulose is the most abundant renewable polysaccharide on earth. The unique physicochemical, structural, biological, and environmental properties of this natural biopolymer have led to its increased application in many fields. The more desirable features of cellulose-based (nano)materials such as biodegradability, renewability, biocompatibility, cost-effectiveness, simplicity of preparation, environmentally friendly nature, and widespread range of applications have converted them into promising compounds in medicine, catalysis, biofuel cells, and water/wastewater treatment processes. Functionalized cellulose-based (nano)materials containing sulfonic acid groups may prove to be one of the most promising sustainable bio(nano)materials of modern times in the field of cellulose science and (nano)technology owing to their intrinsic features, high crystallinity, high specific surface area, abundance, reactivity, and recyclability. In this review, the developments in the application of sulfonated cellulose-based (nano)materials containing sulfonic acid (-SO3H) groups in catalysis, water purification, biological/biomedical, environmental, and fuel cell applications have been reported. This review provides an overview of the methods used to chemically modify cellulose and/or cellulose derivatives in different forms, including nanocrystals, hydrogels, films/membranes, and (nano)composites/blends by introducing sulfonate groups on the cellulose backbone, focusing on diverse sulfonating agents utilized and substitution regioselectivity, and highlights their potential applications in different industries for the generation of alternative energies and products.

18.
Sci Rep ; 14(1): 5711, 2024 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459201

RESUMO

This study aimed to investigate the biological activities of Lactobacillus gasseri SM 05 (L. gasseri) and Lacticaseibacillus casei subsp. casei PTCC 1608 (L. casei) in the black raspberry (Rubus dolichocarpus) juice (BRJ) environment, and also the anti-adhesion activity against Salmonella typhimurium (S. typhimurium) in fermented black raspberry juice (FBRJ). Results showed significant anti-adhesion activity in Caco-2 epithelial cells. In the anti-adhesion process, lactic acid bacteria (LAB) improve intestinal health by preventing the adhesion of pathogens. Adding LAB to BRJ produces metabolites with bacteriocin properties. Major findings of this research include improved intestinal health, improved antidiabetic properties, inhibition of degradation of amino acids, and increase in the nutritional value of foods that have been subjected to heat processing by preventing Maillard inhibition, and inhibition of oxidation of foodstuff by increased antioxidant activity of BRJ. Both species of Lactobacillus effectively controlled the growth of S. typhimurium during BRJ fermentation. Moreover, in all tests, as well as Maillard's and α-amylase inhibition, L. gasseri was more effective than L. casei. The phenolic and flavonoid compounds increased significantly after fermentation by both LAB (p < 0.05). Adding Stevia extract to FBRJ and performing the HHP process showed convenient protection of phenolic compounds compared to heat processing.


Assuntos
Lacticaseibacillus casei , Lactobacillus gasseri , Probióticos , Rubus , Stevia , Humanos , Fermentação , Células CACO-2 , Extratos Vegetais/farmacologia
19.
Sci Rep ; 13(1): 12008, 2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37491465

RESUMO

Recently, the development of heterogeneous nanocatalytic systems using solid supports has been gaining importance due to some advantages such as easy handling, high thermal stability, high efficiency, reusability, and so on. Therefore, the design of catalyst supports for the preparation of stable heterogeneous catalytic systems is of great importance. In this work, Schiff base-modified ZnO particles have been developed (ZnO-Scb) as a novel support. A heterogeneous nanocatalyst system has then been prepared by immobilizing palladium nanoparticles (Pd NPs) on the ZnO-Scb surface as the support. The resulting palladium nanocatalyst (Pd-ZnO-Scb) structure has been characterized by different analytical techniques (FT-IR, XRD, TEM, FE-SEM, elemental mapping and EDS) and used to catalyze the Heck coupling reactions and 4-nitrophenol (4-NP) reduction. Test results revealed that Pd-ZnO-Scb could effectively couple various aryl halides with styrene in yields of up to 98% in short reaction times. Pd-ZnO-Scb was also efficiently used in the complete 4-NP reduction within 135 s at room temperature. Additionally, it was found that Pd-ZnO-Scb was more effective than other reported catalysts in the Heck coupling reaction. Moreover, the recycling tests indicated that Pd-ZnO-Scb could be easily isolated from the reaction medium and reused in seven consecutive catalytic runs while retaining its nanostructure.

20.
Sci Rep ; 13(1): 15494, 2023 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-37726323

RESUMO

Cartilage lesions, especially osteoarthritis (OA), are a common health problem, causing pain and disability in various age groups, principally in older adults and athletes. One of the main challenges to be considered in cartilage tissue repair is the regeneration of cartilage tissue in an active inflammatory environment. Fisetin has various biological effects including anti-inflammatory, antioxidant, apoptotic, and antiproliferative activities. The only disadvantages of fisetin in the pharmaceutical field are its instability and low solubility in aqueous media. This study is aimed at preparing chitosan (CS)-based nanoparticles to yield fisetin with improved bioavailability features. Then, the effect of fisetin-loaded nanoparticles (FNPs) on inflammatory responses in interleukin-1ß (IL-1ß) pretreated human chondrocytes has also been investigated. FNPs presented an average size of 363.1 ± 17.2 nm and a zeta potential of + 17.7 ± 0.1 mV with encapsulation efficiency (EE) and loading capacity (LC) of 78.79 ± 7.7% and 37.46 ± 6.6%, respectively. The viability of human chondrocytes was not affected by blank nanoparticles (BNPs) up to a concentration of 2000 µg/mL. In addition, the hemolysis results clearly showed that FNPs did not damage the red blood cells (RBCs) and had good hemocompatibility within the range investigated. FNPs, similar to fisetin, were able to inhibit the inflammatory responses induced by IL-1ß such as the expression of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) while increasing the production of an anti-inflammatory cytokine such as interleukin-10 (IL-10). Overall, the in vitro evaluation results of the anti-inflammatory activity showed that FNPs can serve as delivery systems to transfer fisetin to treat inflammation in OA.


Assuntos
Anti-Inflamatórios , Osteoartrite , Humanos , Idoso , Anti-Inflamatórios/farmacologia , Osteoartrite/tratamento farmacológico , Inflamação/tratamento farmacológico , Flavonóis
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA