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1.
Gels ; 10(3)2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38534603

RESUMO

The integration of abscisic acid (ABA) into a chitosan-alginate gel blend unveils crucial insights into the formation and stability of these two substances. ABA, a key phytohormone in plant growth and stress responses, is strategically targeted for controlled release within these complexes. This study investigates the design and characterization of this novel controlled-release system, showcasing the potential of alginate-chitosan gel blends in ABA delivery. Computational methods, including molecular dynamics simulations, are employed to analyze the structural effects of microencapsulation, offering valuable insights into complex behavior under varying conditions. This paper focuses on the controlled release of ABA from these complexes, highlighting its strategic importance in drug delivery systems and beyond. This controlled release enables targeted and regulated ABA delivery, with far-reaching implications for pharmaceuticals, agriculture, and plant stress response studies. While acknowledging context dependency, the paper suggests that the liberation or controlled release of ABA holds promise in applications, urging further research and experimentation to validate its utility across diverse fields. Overall, this work significantly contributes to understanding the characteristics and potential applications of chitosan-alginate complexes, marking a noteworthy advancement in the field of controlled-release systems.

2.
Int J Biol Macromol ; 263(Pt 1): 130159, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38368972

RESUMO

In this work, chitosan films loaded with gallic acid and different content of chitin nanofibers were prepared and subjected to different characterization techniques. The results showed that the inclusion of gallic acid to chitosan films caused moderate decrease in water vapor permeability (by 29 %) and increased tensile strength of films (by 169 %) in comparison to the neat chitosan films. Furthermore, it was found that the addition of chitin nanofibers up to 30 % into chitosan/gallic acid films additionally improved tensile strength (by 474 %) and reduced plasticity of films (by 171 %), when compared to the chitosan/gallic acid films. Increased concentration of chitin nanofibers in films reduced the overall water vapor permeability of films by 51 %. In addition, gallic acid and chitin nanofibers had synergic effect on high chitosan film's antioxidant and antifungal activity toward Botrytis cinerea (both above 95 %). Finally, chitosan/gallic acid/chitin nanofibers films reduced decay incidence of strawberries, increased total soluble solid content, and promoted high production of some polyphenols during cold storage, in comparison to the control chitosan films and uncoated strawberry samples. Hence, these results suggest that chitosan/gallic acid/chitin nanofibers can present eco-sustainable approach for preservation of strawberries, giving them additional nutritional value.


Assuntos
Quitosana , Nanofibras , Quitosana/farmacologia , Quitosana/química , Quitina/química , Ácido Gálico/química , Nanofibras/química , Vapor , Embalagem de Alimentos/métodos
3.
Polymers (Basel) ; 15(15)2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37571107

RESUMO

Abscisic acid (ABA) has been proposed to play a significant role in the ripening of nonclimacteric fruit, stomatal opening, and response to abiotic stresses in plants, which can adversely affect crop growth and productivity. The biological effects of ABA are dependent on its concentration and signal transduction pathways. However, due to its susceptibility to the environment, it is essential to find a suitable biotechnological approach to coat ABA for its application. One promising approach is to utilize alginate and chitosan, two natural polysaccharides known for their strong affinity for water and their ability to act as coating agents. In this study, an alginate-chitosan blend was employed to develop an ABA cover. To achieve this, an alginate-chitosan-abscisic acid (ALG-CS-ABA) blend was prepared by forming ionic bonds or complexes with calcium ions, or through dual cross-linking. This was done by dripping a homogeneous solution of alginate-chitosan and ABA into a calcium chloride solution, resulting in the formation of the blend. By combining the unique properties of alginate, chitosan, and ABA, the resulting ALG-CS-ABA blend can potentially offer enhanced stability, controlled release, and improved protection of ABA. These characteristics make it a promising biotechnological approach for various applications, including the targeted delivery of ABA in agricultural practices or in the development of innovative plant-based products. Further evaluation and characterization of the ALG-CS-ABA blend will provide valuable insights into its potential applications in the fields of biomedicine, agriculture, and tissue engineering.

4.
Comput Biol Chem ; 106: 107932, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37487249

RESUMO

Lipopeptides are medicinally essential building blocks with strong hemolytic, antifungal and antibiotic potential. In the present research article, we are presenting our findings regarding the synthesis of N-alkylated lipopeptides via Ugi four-component approach, their antimicrobial potential against pathogenic (Gram-positive and Gram-negative) bacteria, as well as computational studies to investigate the compounds binding affinity and dynamic behavior with MurD antibacterial target. Molecular docking demonstrated the compounds have good binding ability with MurD enzyme. The FT94, FT95 and FT97 compounds revealed binding affinity scores of -8.585 kcal mol- 1, -7.660 kcal mol- 1 and -7.351 kcal mol- 1, respectively. Furthermore, dynamics analysis pointed the systems high structure dynamics. The docking and simulation results were validated by binding free energies, demonstrating solid intermolecular interactions and in the assay in vitro, the Minimal Inhibitory Concentration (MIC) of FT97 to Staphylococcus aureus (S. aureus) was 62.5 µg/mL. In conclusion, a moderate inhibitory response of peptoid FT97 was observed against the Gram-positive bacteria, S. aureus and B. cereus.


Assuntos
Anti-Infecciosos , Staphylococcus aureus , Simulação de Acoplamento Molecular , Antibacterianos/farmacologia , Lipopeptídeos/farmacologia
5.
Int J Biol Macromol ; 238: 124130, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-36963553

RESUMO

In this work, chitin, as a biobased polymer, is used as a precursor to obtain a phosphorylated derivatives. The influence of the different degree of phosphorylation in chitin on pyrolysis pattern was investigated. In order to understand the pyrolysis mechanism and the potential application of phosphorylated chitins, the samples were pyrolyzed at different temperatures and analyzed by FTIR, SEM, and Py-GC/MS analysis. Moreover, the thermal degradation and the evolved gases during chitin degradation and its derivatives were measured. The results showed that phosphorylation of chitin decreased the thermal stability of biopolymer and significantly changed the pattern of pyrolysis compared to neat chitin. The production of long-chain hydrocarbons was detected during pyrolysis of phosphorylated chitin, whereas this was not the case with raw chitin. Those two effects were more pronounced as the degree of phosphorylation increased. Chitin with the degree of phosphorylation (DS 1.35) exhibited the highest selectivity (91 %) towards production of long-chain hydrocarbons (C12-C17) at 500 °C. Moreover, the obtained results allowed to propose, for the first time, the mechanism of pyrolysis of phosphorylated chitin.


Assuntos
Quitina , Pirólise , Quitina/análise , Cromatografia Gasosa-Espectrometria de Massas , Gases , Hidrocarbonetos
6.
Pharmaceutics ; 15(2)2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36839798

RESUMO

In light of the growing bacterial resistance to antibiotics and in the absence of the development of new antimicrobial agents, numerous antimicrobial delivery systems over the past decades have been developed with the aim to provide new alternatives to the antimicrobial treatment of infections. However, there are few studies that focus on the development of a rational design that is accurate based on a set of theoretical-computational methods that permit the prediction and the understanding of hydrogels regarding their interaction with cationic antimicrobial peptides (cAMPs) as potential sustained and localized delivery nanoplatforms of cAMP. To this aim, we employed docking and Molecular Dynamics simulations (MDs) that allowed us to propose a rational selection of hydrogel candidates based on the propensity to form intermolecular interactions with two types of cAMPs (MP-L and NCP-3a). For the design of the hydrogels, specific building blocks were considered, named monomers (MN), co-monomers (CM), and cross-linkers (CL). These building blocks were ranked by considering the interaction with two peptides (MP-L and NCP-3a) as receptors. The better proposed hydrogel candidates were composed of MN3-CM7-CL1 and MN4-CM5-CL1 termed HG1 and HG2, respectively. The results obtained by MDs show that the biggest differences between the hydrogels are in the CM, where HG2 has two carboxylic acids that allow the forming of greater amounts of hydrogen bonds (HBs) and salt bridges (SBs) with both cAMPs. Therefore, using theoretical-computational methods allowed for the obtaining of the best virtual hydrogel candidates according to affinity with the specific cAMP. In conclusion, this study showed that HG2 is the better candidate for future in vitro or in vivo experiments due to its possible capacity as a depot system and its potential sustained and localized delivery system of cAMP.

7.
Materials (Basel) ; 15(14)2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35888365

RESUMO

The present study shows porous activated carbon obtained from Chenopodium quinoa Willd and Quillaja saponaria and their use as potential adsorbents to remove three types of dyes from aqueous solutions. The adsorption results were compared with commercial charcoal to check their efficiency. All porous carbon materials were activated using carbon dioxide and steam and fully characterized. Moreover, the steam-activated samples exhibited a high total pore volume with a BET surface area of around 800 m2 g−1. Batch adsorption experiments showed that commercial charcoal is the charcoal that offered the best adsorption efficiency for tartrazine and sunset yellow FCF. However, in the case of crystal violet, all activated carbons obtained from Chenopodium quinoa Willd and Quillaja saponaria showed the best captures, outperforming commercial charcoal. Molecular dockings of the dyes on the commercial charcoal surface were performed using AutoDock Vina. The kinetic results of the three isotherm's models for the present data follow the order: Langmuir~Freundlich > Temkin.

8.
Mar Drugs ; 20(7)2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35877751

RESUMO

Codium bernabei is a green alga that grows on Chilean coasts. The composition of its structural polysaccharides is still unknown. Hence, the aim of this work is to isolate and characterize the hot water extracted polysaccharide fractions. For this purpose, the water extracts were further precipitated in alcohol (TPs) and acid media (APs), respectively. Both fractions were characterized using different physicochemical techniques such as GC-MS, GPC, FTIR, TGA, and SEM. It is confirmed that the extracted fractions are mainly made of sulfated galactan unit, with a degree of sulfation of 19.3% (TPs) and 17.4% (ATs) and a protein content of 3.5% in APs and 15.6% in TPs. Other neutral sugars such as xylose, glucose, galactose, fucose, mannose, and arabinose were found in a molar ratio (0.05:0.6:1.0:0.02:0.14:0.11) for TPs and (0.05:0.31:1.0:0.03:0.1:0.13) for ATs. The molecular weight of the polysaccharide samples was lower than 20 kDa. Both polysaccharides were thermally stable (Tonset > 190 °C) and showed antioxidant activity according to the ABTS•+ and DPPH tests, where TPs fractions had higher scavenging activity (35%) compared to the APs fractions. The PT and APTTS assays were used to measure the anticoagulant activity of the polysaccharide fractions. In general, the PT activity of the TPs and APs was not different from normal plasma values. The exception was the TPs treatment at 1000 µg mL−1 concentration. The APTTS test revealed that clotting time for both polysaccharides was prolonged regarding normal values at 1000 µg mL−1. Finally, the antitumor test in colorectal carcinoma (HTC-116) cell line, breast cancer (MCF-7) and human leukemia (HL-60) cell lines showed the cytotoxic effect of TPs and APs. Those results suggest the potential biotechnological application of sulfate galactan polysaccharides isolated from a Chilean marine resource.


Assuntos
Clorófitas , Sulfatos , Anticoagulantes/química , Antioxidantes/farmacologia , Clorófitas/química , Galactanos/química , Humanos , Polissacarídeos/química , Sulfatos/química , Água
9.
Molecules ; 26(24)2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34946559

RESUMO

This study investigated the biocomposite pectin films enriched with murta (Ugni molinae T.) seed polyphenolic extract and reinforced by chitin nanofiber. The structural, morphological, mechanical, barrier, colorimetric, and antioxidant activity of films were evaluated. The obtained data clearly demonstrated that the addition of murta seed extract and the high load of chitin nanofibers (50%) provided more cohesive and dense morphology of films and improved the mechanical resistance and water vapor barrier in comparison to the control pectin film. The antioxidant activity ranged between 71% and 86%, depending on the film formulation and concentration of chitin nanofibers. The presented results highlight the potential use of chitin nanofibers and murta seed extract in the pectin matrix to be applied in functional food coatings and packaging, as a sustainable solution.


Assuntos
Materiais Biocompatíveis/química , Quitina/química , Myrtaceae/química , Nanofibras/química , Pectinas/química , Extratos Vegetais/química , Materiais Biocompatíveis/isolamento & purificação , Embalagem de Alimentos , Tamanho da Partícula , Pectinas/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Sementes/química
10.
Mater Sci Eng C Mater Biol Appl ; 131: 112483, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34857269

RESUMO

A rational design accurate based on the use of Statistical Design of the Experiments (DoE) and Molecular Dynamics Simulations Studies allows the prediction and the understanding of thermo-responsive hydrogels prepared regarding their gelation temperature and anti-cancer drug release rate. N-isopropylacrilamide (NIPAM) modified with specific co-monomers and crosslinkers, can be used to prepare "on-demand" thermo-responsive hydrogels with the ideal properties for clinical applications in which local sustained release of drugs is crucial. Two preferential formulations resulting from the predictive studies of DoE and In Silico methods were synthesized by radical polymerization, fully characterized, and loaded with the anticancer drug Doxorubicin (Dox). The hydrogel formulations were characterized by swelling rate, turbidity, FTIR, 1H NMR, SEM, gelation time, rheology, and biocompatibility assays. Both formulations demonstrated adequate morphologic, rheological, and biocompatibility properties; however, important differences in terms of drug retention were detected. As demonstrated by a Dox cumulative release study and posteriorly confirmed by an efficacy assay in an in vitro colorectal cancer model, the formulation composed by NIPAM and 4-penten-1-ol crosslinked with poly(ethylene glycol) diacrylate (PEGDA) (PNiPenPH) present a slow release over the time, presenting ideal properties to become and ideal depot system for the local sustained release of anticancer drugs as adjuvant therapy or in the case of non-resectable tumors.


Assuntos
Antineoplásicos , Neoplasias do Colo , Antineoplásicos/farmacologia , Neoplasias do Colo/tratamento farmacológico , Preparações de Ação Retardada , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Humanos , Hidrogéis , Temperatura
11.
Polymers (Basel) ; 13(22)2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34833292

RESUMO

Pesticides are used worldwide to increase crop yields in agriculture. However, their toxicity and accumulation capacity can make them toxic to the environment, animals and humans. In the case of workers chronically exposed to these substances, they must be sampled continuously, so urine is an excellent option. In this sense, this study proposes to use poly(vinyl alcohol)-malic acid hydrogels, and chitosan-coated calcium alginate as new sorbent phases to be used in pesticide determination processes in urine. To better understand the behavior of these materials in the capture and desorption process, molecular dynamics simulations (MDS) were used, and desorption experiments were performed, using mechanical agitation, ultrasound, and pH variation in the desorption process, in order to optimize the parameters to obtain better recoveries. Under the optimal experimental conditions, the maximum recoveries were of the order of 11% (CFN), 3% (KCF), 53% (DMT), 18% (MTD) and 35% (MTL). Although the recoveries were not exhaustive, they are a first approximation for the use of these new sorbent phases in the determination of this type of compound in aqueous solutions and urine.

12.
Int J Biol Macromol ; 186: 92-99, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34246675

RESUMO

The efficient use of waste from food processing industry is one of the innovative approaches within sustainable development, because it can be transferred into added value products, which could improve economic, energetic and environmental sectors. In this context, the squid pen waste from seafood industry was used as raw material to obtain nanofibrous ß-chitin films. In order to extend functionality of obtained films, elderberry extract obtained from biomass was added at different concentrations. The tensile strength of chitin-elderberry extract films was improved by 52%, elongation at break by 153% and water vapor barrier by 65%. The obtained material showed distinct color change when subjected to acidic or basic solutions. It was proven by CIELab color analysis that all color changes could be easily perceived visually. In addition, the obtained nanofibrous film was successfully used to monitor the freshness of Hake fish. Namely, when the film was introduced in a package that contained fresh fish, its color was efficiently changed within the time during the storage at 4 °C. The obtained results demonstrated that food processing waste could be efficiently valorized, and could give sustainable food package design as a spoilage indicator of high protein food.


Assuntos
Quitina/isolamento & purificação , Decapodiformes , Manipulação de Alimentos , Embalagem de Alimentos , Nanofibras , Alimentos Marinhos , Materiais Inteligentes/isolamento & purificação , Resíduos , Animais , Cor , Colorimetria , Contaminação de Alimentos , Armazenamento de Alimentos , Frutas , Gadiformes , Concentração de Íons de Hidrogênio , Nanotecnologia , Extratos Vegetais/química , Sambucus , Temperatura , Resistência à Tração , Tempo
13.
Plants (Basel) ; 10(5)2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-34064964

RESUMO

Chloroplasts need to import preproteins and amino acids from the cytosol during their light-induced differentiation. Similarly, chloroplasts have to export organic matter including proteins and amino acids during leaf senescence. Members of the PRAT (preprotein and amino acid transporter) family are candidate transporters for both processes. Here, we defined the role of two small PRAT gene families, At4g26670 and At5g55510 (HP20 subfamily) versus At3g49560 and At5g24650 (HP30 subfamily) during greening of etiolated plants and during leaf senescence. Using a combination of reverse genetics, protein biochemistry and physiological tools, evidence was obtained for a role of chloroplast HP20, HP30 and HP30-2 in protein, but not amino acid, import into chloroplasts. HP20, HP30 and HP30-2 form larger complexes involved in the uptake of transit sequence-less cytosolic precursors. In addition, we identified a fraction of HP30-2 in mitochondria where it served a similar function as found for chloroplasts and operated in the uptake of transit sequence-less cytosolic precursor proteins. By contrast, HP22 was found to act in the export of proteins from chloroplasts during leaf senescence, and thus its role is entirely different from that of its orthologue, HP20. HP22 is part of a unique protein complex in the envelope of senescing chloroplasts that comprises at least 11 proteins and contains with HP65b (At5g55220) a protein that is related to the bacterial trigger factor chaperone. An ortholog of HP65b exists in the cyanobacterium Synechocystis and has previously been implicated in protein secretion. Whereas plants depleted of either HP22 or HP65b or even both were increasingly delayed in leaf senescence and retained much longer stromal chloroplast constituents than wild-type plants, HP22 overexpressors showed premature leaf senescence that was associated with accelerated losses of stromal chloroplast proteins. Together, our results identify the PRAT protein family as a unique system for importing and exporting proteins from chloroplasts.

14.
Int J Mol Sci ; 22(11)2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34072090

RESUMO

Hydrogels obtained from combining different polymers are an interesting strategy for developing controlled release system platforms and tissue engineering scaffolds. In this study, the applicability of sodium alginate-g-(QCL-co-HEMA) hydrogels for these biomedical applications was evaluated. Hydrogels were synthesized by free-radical polymerization using a different concentration of the components. The hydrogels were characterized by Fourier transform-infrared spectroscopy, scanning electron microscopy, and a swelling degree. Betamethasone release as well as the in vitro cytocompatibility with chondrocytes and fibroblast cells were also evaluated. Scanning electron microscopy confirmed the porous surface morphology of the hydrogels in all cases. The swelling percent was determined at a different pH and was observed to be pH-sensitive. The controlled release behavior of betamethasone from the matrices was investigated in PBS media (pH = 7.4) and the drug was released in a controlled manner for up to 8 h. Human chondrocytes and fibroblasts were cultured on the hydrogels. The MTS assay showed that almost all hydrogels are cytocompatibles and an increase of proliferation in both cell types after one week of incubation was observed by the Live/Dead® assay. These results demonstrate that these hydrogels are attractive materials for pharmaceutical and biomedical applications due to their characteristics, their release kinetics, and biocompatibility.


Assuntos
Alginatos/química , Betametasona/administração & dosagem , Portadores de Fármacos , Hidrogéis/química , Metacrilatos/química , Polímeros/química , Alicerces Teciduais/química , Animais , Técnicas de Cultura de Células , Proliferação de Células , Sobrevivência Celular/efeitos dos fármacos , Condrócitos , Preparações de Ação Retardada , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Humanos , Hidrogéis/síntese química , Cinética , Camundongos , Estrutura Molecular , Análise Espectral
15.
Mar Drugs ; 19(4)2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33810536

RESUMO

ß-chitin was isolated from marine waste, giant Humboldt squid Dosidicus gigas, and further converted to nanofibers by use of a collider machine under acidic conditions (pH 3). The FTIR, TGA, and NMR analysis confirmed the efficient extraction of ß-chitin. The SEM, TEM, and XRD characterization results verified that ß-chitin crystalline structure were maintained after mechanical treatment. The mean particle size of ß-chitin nanofibers was in the range between 10 and 15 nm, according to the TEM analysis. In addition, the ß-chitin nanofibers were converted into films by the simple solvent-casting and drying process at 60 °C. The obtained films had high lightness, which was evidenced by the CIELAB color test. Moreover, the films showed the medium swelling degree (250-290%) in aqueous solutions of different pH and good mechanical resistance in the range between 4 and 17 MPa, depending on film thickness. The results obtained in this work show that marine waste can be efficiently converted to biomaterial by use of mild extractive conditions and simple mechanical treatment, offering great potential for the future development of sustainable multifunctional materials for various industrial applications such as food packaging, agriculture, and/or wound dressing.


Assuntos
Materiais Biocompatíveis , Quitina/isolamento & purificação , Decapodiformes/metabolismo , Nanofibras , Resíduos , Animais , Configuração de Carboidratos , Quitina/química , Tamanho da Partícula , Propriedades de Superfície , Viscosidade
16.
Pharmaceutics ; 12(10)2020 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-33080791

RESUMO

A series of hydrogels with a specific release profile of linezolid was successfully synthesized. The hydrogels were synthesized by cross-linking polyvinyl alcohol (PVA) and aliphatic dicarboxylic acids, which include succinic acid (SA), glutaric acid (GA), and adipic acid (AA). The three crosslinked hydrogels were prepared by esterification and characterized by equilibrium swelling ratio, infrared spectroscopy, thermogravimetric analysis, mechanical properties, and scanning electron microscopy. The release kinetics studies of the linezolid from prepared hydrogels were investigated by cumulative drug release and quantified by chromatographic techniques. Mathematical models were carried out to understand the behavior of the linezolid release. These data revealed that the sustained release of linezolid depends on the aliphatic dicarboxylic acid chain length, their polarity, as well as the hydrogel crosslinking degree and mechanical properties. The in vitro antibacterial assay of hydrogel formulations was assessed in an Enterococcus faecium bacterial strain, showing a significant activity over time. The antibacterial results were consistent with cumulative release assays. Thus, these results demonstrated that the aliphatic dicarboxylic acids used as crosslinkers in the PVA hydrogels were a determining factor in the antibiotic release profile.

17.
Molecules ; 25(4)2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32069902

RESUMO

Antimicrobial resistance to conventional antibiotics and the limited alternatives to combat plant-threatening pathogens are worldwide problems. Antibiotic lipopeptides exert remarkable membrane activity, which usually is not prone to fast resistance formation, and often show organism-type selectivity. Additional modes of action commonly complement the bioactivity profiles of such compounds. The present work describes a multicomponent-based methodology for the synthesis of cyclic polycationic lipopeptides with stabilized helical structures. The protocol comprises an on solid support Ugi-4-component macrocyclization in the presence of a lipidic isocyanide. Circular dichroism was employed to study the influence of both macrocyclization and lipidation on the amphiphilic helical structure in water and micellar media. First bioactivity studies against model phytopathogens demonstrated a positive effect of the lipidation on the antimicrobial activity.


Assuntos
Antifúngicos/química , Lactamas/química , Lipopeptídeos/química , Peptídeos Cíclicos/química , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Antifúngicos/síntese química , Antifúngicos/farmacologia , Botrytis/efeitos dos fármacos , Lipopeptídeos/síntese química , Lipopeptídeos/farmacologia , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/farmacologia , Phytophthora infestans/efeitos dos fármacos
18.
Antioxidants (Basel) ; 8(10)2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31601036

RESUMO

We investigated the potential of two oil extracts from seeds of Colliguaya integerrima (CIO) and Cynara cardunculus (CO) to use as nutritionally edible oils. For this purpose, oil quality was accessed by determining the fatty acid composition, peroxide value, acid value, iodine value, saponification number, phenolic contents, and oxidative stability during thermally induced oxidation of CIO and CO oils and compared to those of extra-virgin olive oil (EVOO). The chemical composition results demonstrated that both oils could be nutritional sources of essential unsaturated fatty acids. Moreover, according to the gravimetric analysis, the main decomposition step occurred in the temperature range of 200-420 °C, showing a similar thermal behavior of EVOO oil. However, CO and EVOO oils showed a higher phenolic content at degradation onset temperature (T0) in contrast with CIO oil. The antioxidant activity of the different studied oils showed a direct correlation with the phenol contents, up to temperatures around 180 °C, where the percentage of free radical scavenging assay for EVOO was higher than CO in contrast with the TPC values. Finally, we analyzed the minor components before and after heating CIO and CO at 180 °C by gas chromatography-mass spectrometry (GC-MS) using library search programs.

19.
Pharmaceutics ; 11(9)2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31480682

RESUMO

This research proposes the rational modeling, synthesis and evaluation of film dressing hydrogels based on polyvinyl alcohol crosslinked with 20 different kinds of dicarboxylic acids. These formulations would allow the sustained release of simultaneous bioactive compounds including allantoin, resveratrol, dexpanthenol and caffeic acid as a multi-target therapy in wound healing. Interaction energy calculations and molecular dynamics simulation studies allowed evaluating the intermolecular affinity of the above bioactive compounds by hydrogels crosslinked with the different dicarboxylic acids. According to the computational results, the hydrogels crosslinked with succinic, aspartic, maleic and malic acids were selected as the best candidates to be synthesized and evaluated experimentally. These four crosslinked hydrogels were prepared and characterized by FTIR, mechanical properties, SEM and equilibrium swelling ratio. The sustained release of the bioactive compounds from the film dressing was investigated in vitro and in vivo. The in vitro results indicate a good release profile for all four analyzed bioactive compounds. More importantly, in vivo experiments suggest that prepared formulations could considerably accelerate the healing rate of artificial wounds in rats. The histological studies show that these formulations help to successfully reconstruct and thicken epidermis during 14 days of wound healing. Moreover, the four film dressings developed and exhibited excellent biocompatibility. In conclusion, the novel film dressings based on hydrogels rationally designed with combinatorial and sustained release therapy could have significant promise as dressing materials for skin wound healing.

20.
Beilstein J Org Chem ; 15: 1210-1216, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31293668

RESUMO

The multicomponent synthesis of prolyl pseudo-peptide catalysts using the Ugi reaction with furfurylamines or isocyanides is described. The incorporation of such a polymerizable furan handle enabled the subsequent polymerization of the peptide catalyst with furfuryl alcohol, thus rendering polyfurfuryl alcohol-supported catalysts for applications in heterogeneous enamine catalysis. The utilization of the polymer-supported catalysts in both batch and continuous-flow organocatalytic procedures proved moderate catalytic efficacy and enantioselectivity, but excellent diastereoselectivity in the asymmetric Michael addition of n-butanal to ß-nitrostyrene that was used as a model reaction. This work supports the potential of multicomponent reactions towards the assembly of catalysts and their simultaneous functionalization for immobilization.

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