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1.
Mol Ther ; 32(2): 440-456, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38213031

RESUMO

Here we introduce a first-in-class microRNA-sensitive oncolytic Zika virus (ZIKV) for virotherapy application against central nervous system (CNS) tumors. The described methodology produced two synthetic modified ZIKV strains that are safe in normal cells, including neural stem cells, while preserving brain tropism and oncolytic effects in tumor cells. The microRNA-sensitive ZIKV introduces genetic modifications in two different virus sites: first, in the established 3'UTR region, and secondly, in the ZIKV protein coding sequence, demonstrating for the first time that the miRNA inhibition systems can be functional outside the UTR RNA sites. The total tumor remission in mice bearing human CNS tumors, including metastatic tumor growth, after intraventricular and systemic modified ZIKV administration, confirms the promise of this virotherapy as a novel agent against brain tumors-highly deadly diseases in urgent need of effective advanced therapies.


Assuntos
Neoplasias do Sistema Nervoso Central , MicroRNAs , Terapia Viral Oncolítica , Vírus Oncolíticos , Infecção por Zika virus , Zika virus , Humanos , Camundongos , Animais , Vírus Oncolíticos/genética , Zika virus/genética , MicroRNAs/genética , Infecção por Zika virus/terapia , Terapia Viral Oncolítica/métodos
2.
J Org Chem ; 89(12): 8500-8512, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38842033

RESUMO

A highly enantioselective protocol for the conjugate addition of 2-arylimidazo[1,2-a]pyridines and other imidazo derivatives to α,ß-unsaturated 2-acylimidazoles is described. The method uses a previously reported chiral-at-metal rhodium catalyst and provides the corresponding adducts in yields of 25-98% with enantioselectivities up to er > 99:1. Additionally, the transformation proceeds under mild conditions using ethanol as the solvent at room temperature.

3.
Org Biomol Chem ; 22(11): 2175-2181, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38259235

RESUMO

Herein, we report a KIO3-catalyzed oxidative coupling of thiols to their corresponding disulfides in water, in a short time and at ambient temperature. The reaction has a broad scope and exhibits good functional group tolerance, resulting in the desired products in excellent yields. This approach allows the reuse of the reaction system in multiple cycles and scale-up. Furthermore, the current protocol demonstrates compatibility for in situ generation of disulfides and post application in C(sp2)-H bond sulfenylation.

4.
Prep Biochem Biotechnol ; 54(1): 1-11, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37071540

RESUMO

This study describes the production, characterization and application of an endoglucanase from Penicillium roqueforti using lignocellulosic agro-industrial wastes as the substrate during solid-state fermentation. The endoglucanase was generated after culturing with different agro-industrial wastes for 96 h without any pretreatment. The highest activity was obtained at 50 °C and pH 4.0. Additionally, the enzyme showed stability in the temperature and pH ranges of 40-80 °C and 4.0-5.0, respectively. The addition of Ca2+, Zn2+, Mg2+, and Cu2+ increased enzymatic activity. Halotolerance as a characteristic of the enzyme was confirmed when its activity increased by 35% on addition of 2 M NaCl. The endoglucanase saccharified sugarcane bagasse, coconut shell, wheat bran, cocoa fruit shell, and cocoa seed husk. The Box-Behnken design was employed to optimize fermentable sugar production by evaluating the following parameters: time, substrate, and enzyme concentration. Under ideal conditions, 253.19 mg/g of fermentable sugars were obtained following the saccharification of wheat bran, which is 41.5 times higher than that obtained without optimizing. This study presents a thermostable, halotolerant endoglucanase that is resistant to metal ions and organic solvents with the potential to be applied in producing fermentable sugars for manufacturing biofuels from agro-industrial wastes.


Assuntos
Celulase , Saccharum , Celulase/química , Celulose , Fibras na Dieta , Fermentação , Resíduos Industriais , Projetos de Pesquisa , Saccharum/metabolismo , Açúcares , Cálcio/química , Cobre/química , Zinco/química , Magnésio/química
5.
Genes Immun ; 24(2): 71-80, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36792680

RESUMO

Ulcerative Colitis (UC) is an inflammatory disease characterized by colonic mucosal lesions associated with an increased risk of carcinogenesis. UC pathogenesis involves environmental and genetic factors. Genetic studies have indicated the association of gene variants coding for the divalent metal ion transporter SLC11A1 protein (formerly NRAMP1) with UC susceptibility in several animal species. Two mouse lines were genetically selected for high (AIRmax) or low (AIRmin) acute inflammatory responses (AIR). AIRmax is susceptible, and AIRmin is resistant to DSS-induced colitis and colon carcinogenesis. Furthermore, AIRmin mice present polymorphism of the Slc11a1 gene. Here we investigated the possible modulating effect of the Slc11a1 R and S variants in DSS-induced colitis by using AIRmin mice homozygous for Slc11a1 R (AIRminRR) or S (AIRminSS) alleles. We evaluated UC by the disease activity index (DAI), considering weight loss, diarrhea, blood in the anus or feces, cytokines, histopathology, and cell populations in the distal colon epithelium. AIRminSS mice have become susceptible to DSS effects, with higher DAI, IL6, G-CSF, and MCP-1 production and morphological and colon histopathological alterations than AIRminRR mice. The results point to a role of the Slc11a1 S allele in DSS colitis induction in the genetic background of AIRmin mice.


Assuntos
Colite Ulcerativa , Colite , Animais , Camundongos , Carcinogênese , Colite/induzido quimicamente , Colite/genética , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/genética , Sulfato de Dextrana/efeitos adversos , Modelos Animais de Doenças , Suscetibilidade a Doenças , Inflamação/genética , Camundongos Endogâmicos C57BL , Polimorfismo Genético
6.
Biotechnol Appl Biochem ; 70(3): 1310-1319, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36585894

RESUMO

Guava juice is cloudy and viscous, which hinders filtration, decreases yield, and causes the loss of quality after its processing and during storage. This study aimed to evaluate enzymatic treatment effects using crude multi-enzymatic extracts (CME) obtained from Rhodotorula mucilaginosa, Rhodotorula orizycola, and Pseudozyma sp. produced by submerse fermentation in the extraction of juice guava. Mixtures of 100 ml of guava pulp and multi-enzymatic extracts proposed by Doehlert planning were incubated under constant agitation at 150 rpm and 50°C, and a Doehlert design was applied as a multivariate optimization strategy. The optimal conditions using the multi-enzymatic extract were: 0.4% (v/v) of CME for 131 min for the multi-enzymatic treatment using Pseudozyma sp.; 3.0% (v/v) of CME for 154 min using the R. mucilaginosa CME; and 5.0% (v/v) of CME for 90 min using R. oryzicola. The maximum viscosity reduction values for the juices treated with the CME of yeasts were 10.33%, 86.38%, and 13.33% for the juices treated with the CME of Pseudozyma sp., R. mucilaginosa, and R. orizycola, respectively. The physical-chemical properties were improved after treatment with CMEs, yielding a reduction of clarity, increase of total soluble solids and reducing sugars, and decreasing the acidity (pH) for all treatments with enzymatic extracts of all strains. The yeasts studied showed a potential for CME production to be applied to juice, improving the quality of the juice, and R. mucilaginosa was the most prominent yeast due to most significant reduction of viscosity in guava juice.


Assuntos
Psidium , Psidium/química , Frutas/química , Extratos Vegetais/química
7.
Biotechnol Appl Biochem ; 70(1): 184-192, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35338782

RESUMO

The enormous amount of agroindustrial residues generated in Brazil can be used as biomass to produce fermentable sugars. This study compared the pretreatments with different proportions of dilute acid. The method involved pretreatment with 0.5%, 1%, and 1.5% (v/v) sulfuric acid, followed by hydrolysis using the halotolerant and thermostable endoglucanase from Botrytis ricini URM 5627. The physicochemical characterization of plant biomass was performed using XRD, FTIR, and SEM. The pretreatment significantly increased the production of fermentable sugars following enzymatic saccharification from wheat bran, sugarcane bagasse, and rice husk: 153.67%, 91.98%, and 253.21% increment in sugar production; 36.39 mg⋅g-1 ± 1.23, 39.55 mg⋅g-1 ± 1.70, and 42.53 mg⋅g-1 ± 7.61 mg⋅L-1 of glucose; and 3.26 ± 0.35 mg⋅g-1 , 3.61mg⋅g-1 ± 0.74 and 3.59 mg⋅g-1 ± 0.80 of fructose were produced, respectively. In conclusion, biomass should preferably be pretreated before the enzymatic saccharification using B. ricini URM 5627 endoglucanase.


Assuntos
Celulase , Saccharum , Celulose/metabolismo , Celulase/metabolismo , Fermentação , Saccharum/metabolismo , Glucose , Hidrólise
8.
Prep Biochem Biotechnol ; 53(9): 1154-1163, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36794850

RESUMO

Lignocellulosic residues, such as cocoa bean shell (FI), are generated in large quantities during agro-industrial activities. Proper management of residual biomass through solid state fermentation (SSF) can be effective in obtaining value-added products. The hypothesis of the present work is that the bioprocess promoted by P. roqueforti can lead to structural changes in the fibers of the fermented cocoa bean shell (FF) that confer characteristics of industrial interest. To unveil such changes, the techniques of FTIR, SEM, XRD, TGA/TG were used. After SSF, an increase of 36.6% in the crystallinity index was observed, reflecting the reduction of amorphous components such as lignin in the FI residue. Furthermore, an increase in porosity was observed through the reduction of the 2θ angle, which gives the FF a potential candidate for applications of porous products. The FTIR results confirm the reduction in hemicellulose content after SSF. The thermal and thermogravimetric tests showed an increase in the hydrophilicity and thermal stability of FF (15% decomposition) in relation to the by-product FI (40% decomposition). These data provided important information regarding changes in the crystallinity of the residue, existing functional groups and changes in degradation temperatures.


This work presents a new approach for solid state fermentation based on the study of structural changes caused by Penicillium roquefort, which is important to understand the changes in the lignocellulosic matrix after the fungus growth. The results provided important information regarding changes in the crystallinity of the residue, existing functional groups and changes in degradation temperatures. Consequently, they can help in proposals for the total use of the residual solid after fermentation, as well as contribute to reducing the lack of this information in the literature.


Assuntos
Penicillium , Penicillium/metabolismo , Lignina/metabolismo , Fermentação
9.
J Food Sci Technol ; 60(7): 1981-1991, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37206424

RESUMO

The objective was to optimize the phenolic compounds extraction from cocoa shells using the simplex-centroid design with a mixture of solvents (water, methanol, and acetone) as its components, to prove the presence of these compounds and antioxidant activity. Also, the development of dairy products, such as milk beverages and dairy desserts, with bioactive compounds, through the replacement of cocoa powder by cocoa shell was studied and evaluated sensorially. The extraction optimization indicated that a solvent with 56.44% water, 23.77% methanol, and 19.80% acetone are ideal for maximizing the phenolic compounds. In addition, the cocoa shell showed a high antioxidant activity by the methods ß-carotene/linoleic acid, FRAP, and phosphomolybdenum complex. The Check-All-That-Apply, Cochran's Q test, contingency analysis, and hierarchical cluster analysis allowed description characteristics of the dairy products and showed sensory differences between formulations with 100% cocoa shell and others. Both dairy products had good sensory acceptance in all attributes evaluated (appearance, flavor, texture, and overall impression), and their scores did not differ statistically by Tukey's test (p > 0.05). Thus, the cocoa shell is shown as an alternative substitute ingredient to be used in the dairy industry.

10.
Genes Immun ; 23(1): 23-32, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34966170

RESUMO

Two non-inbred mouse lines, phenotypically selected for maximal (AIRmin) and minimal (AIRmax) acute inflammatory response, show differential susceptibility/resistance to the development of several chemically-induced tumor types. An intercross pedigree of these mice was generated and treated with the chemical carcinogen dimethylhydrazine, which induces lung and intestinal tumors. Genome wide high-density genotyping with the Restriction Site-Associated DNA genotyping (2B-RAD) technique was used to map genetic loci modulating individual genetic susceptibility to both lung and intestinal cancer. Our results evidence new common quantitative trait loci (QTL) for those phenotypes and provide an improved understanding of the relationship between genomic variation and individual genetic predisposition to tumorigenesis in different organs.


Assuntos
Neoplasias do Colo , Locos de Características Quantitativas , Animais , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/genética , Predisposição Genética para Doença , Pulmão , Camundongos , Camundongos Endogâmicos
11.
Crit Rev Food Sci Nutr ; 62(14): 3913-3929, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33427482

RESUMO

Naturally occurring plant-based gums and their engineered bio-nanostructures have gained an immense essence of excellence in several industrial, biotechnological, and biomedical sectors of the modern world. Gums derived from bio-renewable resources that follow green chemistry principles are considered green macromolecules with unique structural and functional attributes. For instance, gum mostly obtained as exudates are bio-renewable, bio-degradable, bio-compatible, sustainable, overall cost-effective, and nontoxic. Gum exudates also offer tunable attributes that play a crucial role in engineering bio-nanostructures of interest for several bio- and non-bio applications, e.g., food-related items, therapeutic molecules, sustained and controlled delivery cues, bio-sensing constructs, and so on. With particular reference to plant gum exudates, this review focuses on applied perspectives of various gums, i.e., gum Arabic, gum albizzia, gum karaya, gum tragacanth, and gum kondagogu. After a brief introduction with problem statement and opportunities, structural and physicochemical attributes of plant-based natural gums are presented. Following that, considerable stress is given to green synthesis and stabilization of gum-based bio-nanostructures. The final part of the review focuses on the bio- and non-bio related applications of various types of gums polysaccharides-oriented bio-nanostructures.


Assuntos
Nanoestruturas , Tragacanto , Goma Arábica/química , Gomas Vegetais , Polissacarídeos , Tragacanto/química
12.
Biotechnol Appl Biochem ; 69(3): 1284-1299, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34021924

RESUMO

The production and direct employment in organic medium in the ethyl-oleate synthesis of a fermented solid (FS) containing lipases by Penicillium roqueforti ATCC 10110 (PR10110) was investigated. For the production of this FS, the solid-state fermentation of different agroindustrial waste was used, such as: cocoa shell, sugarcane bagasse, sugarcane bagasse with cocoa shell, and cocoa shell with soybean oil and nutrient solution. The response surface methodology was used to study the effect of independent variables of initial moisture content and inductor concentration, as carbon source and inducer on lipase production. The characterization of the fermented solid in organic medium was also carried out. The highest lipase activity (53 ± 5 U g-1 ) was 16% higher than that obtained with the nonoptimized conditions. The characterization studies observed high stability of the FS in organic solvents for 5 h at 30°C, as well as at different temperatures, and the residual activity was measured against triolein. The FS was also able to catalyze ethyl-oleate synthesis maintaining high relative conversion over five reaction cycles of 96 h at 40°C in n-heptane. These results are promising and highlight the use of the FS containing PR10110 lipases for the first time in biocatalytic processes.


Assuntos
Celulose , Saccharum , Emprego , Fermentação , Lipase/metabolismo , Ácido Oleico , Ácidos Oleicos , Penicillium , Saccharum/metabolismo
13.
Biotechnol Appl Biochem ; 69(5): 2069-2080, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34617635

RESUMO

The increased demand for cheese and the limited availability of calf rennet justifies the search for milk-clotting enzymes from alternative sources. Trypsin-like protease by Penicillium roqueforti was produced by solid-state fermentation using cocoa shell waste as substrate. The production of a crude enzyme extract that is rich in this enzyme was optimized using a Doehlert-type multivariate experimental design. The biochemical characterization showed that the enzyme has excellent activity and stability at alkaline pH (10-12) and an optimum temperature of 80°C, being stable at temperatures above 60°C. Enzymatic activity was maximized in the presence of Na+ (192%), Co2+ (187%), methanol (153%), ethanol (141%), and hexane (128%). Considering the biochemical characteristics obtained and the milk coagulation activity, trypsin-like protease can be applied in the food industry, such as in milk clotting and in the fabrication of cheeses.


Assuntos
Queijo , Leite , Animais , Fermentação , Tripsina , Concentração de Íons de Hidrogênio
14.
Biotechnol Appl Biochem ; 69(5): 1843-1856, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34496084

RESUMO

Leaves of Croton argyrophyllus contain essential oil with promising active components for the development of drugs and botanical insecticides. In this study, we evaluated the enzymatic pretreatment process to increase the extraction of essential oil from fresh and dried leaves of C. argyrophyllus. Pretreatment was carried out using a crude multienzymatic extract obtained via solid-state fermentation of forage palm by Aspergillus niger, and the extraction was performed by hydrodistillation. A Doehlert matrix was used to optimize the enzymatic pretreatment variables temperature and enzymatic extract. The effect of pretreatment time was also investigated. At optimum experimental conditions, 41.34°C, 140 min, and 130.73 mL of enzyme in 369.27 mL of water, the essential oil yield from fresh leaves subjected to enzymatic pretreatment increased by 9.35% and that from dry leaves by 6.77%. Based on chromatographic analysis (GC-MS), no compound was degraded in the extraction process. Micromorphological analysis confirmed the rupture of the glandular trichomes, favoring essential oil release. Therefore, enzymatic pretreatment associated with hydrodistillation increased the essential oil yield and is a promising application to obtain essential oil for therapeutic purposes without altering its composition.


Assuntos
Croton , Óleos Voláteis , Óleos Voláteis/análise , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Croton/química , Aspergillus niger , Folhas de Planta/química , Extratos Vegetais/química
15.
Biotechnol Appl Biochem ; 69(5): 2081-2090, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34617628

RESUMO

Nitrilases and nitrile hydratases/amidases hydrolyze nitriles into carboxylic acids and/or amides, which are used in industrial chemical processes. In the present study, 26 microorganisms, including yeasts and filamentous fungi, in a minimum solid mineral medium supplemented with glucose and phenylacetonitrile were screened to evaluate their biocatalytic potential. Of these microorganisms, five fungi of the genus Aspergillus were selected and subjected to colorimetry studies to evaluate the production and distinction of nitrilase and nitrile hydratase/amidase enzymes. Aspergillus parasiticus Speare 7967 and A. niger Tiegh. 8285 produced nitrilases and nitrile hydratase, respectively. Nitrilase optimization was performed using a Box-Behnken design (BBD) and fungus A. parasiticus Speare 7967 with phenylacetonitrile volume (µl), pH, and carbohydrate source (starch:glucose; g/g) as independent variables and nitrilase activity (U ml-1 ) as dependent variable. Maximum activity (2.97 × 10-3  U ml-1 ) was obtained at pH 5.5, 80 µl of phenylacetonitrile, and 15 g of glucose. A. parasiticus Speare 7967 showed promise in the biotransformation of nitriles to carboxylic acids.


Assuntos
Aminoidrolases , Ensaios de Triagem em Larga Escala , Fungos , Nitrilas/metabolismo , Ácidos Carboxílicos/metabolismo , Aspergillus/metabolismo , Glucose
16.
Biotechnol Lett ; 44(1): 89-99, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34738223

RESUMO

OBJECTIVES: To immobilize Candida rugosa lipase in Accurel MP 1000 (CRL-AMP) by physical adsorption in organic medium and apply in the synthesis of wax esters dodecanoyl octadecanoate 1 and hexadecanoyl octadecanoate 2 in a heptane medium, as well as evaluating the stability and recyclability of CRL-AMP in six reaction cycles. RESULTS: The specific activity (Asp) for CRL-AMP was 200 ± 20 U mg-1. Its catalytic activity was 1300 ± 100 U g-1. CRL-AMP was used in the synthesis of esters in heptane medium with a 1:1 acid:alcohol molar ratio at 45 °C and 200 rpm. In synthesis 1, conversion was 62.5 ± 3.9% in 30 min at 10% m v-1 and 56.9 ± 2.8% in 54 min at 5% m v-1; while in synthesis 2, conversion was 79.0 ± 3.9% in 24 min at 10% m v-1, and 46.0 ± 2.4% in 54 min at 5% m v-1. Reuse tests after six consecutive cycles of reaction showed that the biocatalyst retained approximately 50% of its original activity for both reaction systems. CONCLUSIONS: CRL-AMP showed a high potential in the production of wax esters, since it started from low enzymatic load and high specific activities and conversions were obtained, in addition to allowing an increase in stability and recyclability of the prepared biocatalyst.


Assuntos
Ésteres , Lipase , Biocatálise , Candida/metabolismo , Emolientes , Estabilidade Enzimática , Enzimas Imobilizadas/metabolismo , Esterificação , Lipase/metabolismo , Saccharomycetales
17.
Prep Biochem Biotechnol ; 52(3): 325-330, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34261412

RESUMO

Lipases (triacylglycerol hydrolases, EC 3.1.1.3) are a class of enzymes with high industrial importance. An option for the production of this enzyme is through fungal growth via solid-state fermentation (SSF). Thus, this research presents a study of lipase production by Penicillium roqueforti ATCC 10110 through SSF using cocoa bran residues (Theobroma cacao) as a substrate. To achieve maximum lipase production, fermentation time (0 to 120 h) and palm oil (PO) percentage (0 to 50%) were optimized through analysis of one factor at a time (OFAT), with lipase activity as the response. The amount of cocoa was fixed (5 g), the incubation temperature was maintained at 27 °C, and the moisture content was established at 70%. For a 72 h incubation, the highest enzyme activity achieved using SSF without adding PO was 14.67 ± 1.47 U g-1, whereas with PO (30%), it was 33.33 ± 3.33 U g-1, thus demonstrating a 44% increase in enzyme activity. Through the OFAT methodology, it was possible to confirm that supplementation with palm residue was efficient and maximized the lipase of P. roqueforti ATCC 10110.


Assuntos
Arecaceae/metabolismo , Cacau/metabolismo , Fermentação , Lipase/biossíntese , Penicillium/metabolismo
18.
Prep Biochem Biotechnol ; 52(8): 885-893, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34965202

RESUMO

Solid state fermentation (SSF) simulates the natural conditions fungal growth, where the amount of water in the reaction medium must be restricted, thus limiting the use of liquid substrate. An analytical strategy to deal with this limitation is the design of blending with constraints. Thus, the objective of the work was to optimize two constrained waste mixtures for the production of lipase by Penicillium roqueforti ATCC 10110 under SSF, using different substrates that combine solid and liquid waste. For this, the best fermentation time was determined through a fermentative profile, afterwards a restricted-mix design with lower and upper limits of the components of mixture I (cocoa residue, solid palm oil residue and liquid palm oil residue) and II (cocoa residue, mango residue and palm oil residue liquid palm) was applied. By means of Pareto and contour graphs, the maximum production points of lipase in mixtures I (6.67 ± 0.34 U g-1) and II (6.87 ± 0.35 U g-1) were obtained. The restricted mixture design proved to be a promising tool in the production of lipase by P. roqueforti ATCC 10110 under SSF since the use of restrictions is useful when intending to combine solid and liquid residues in fermentation processes.


Assuntos
Resíduos Industriais , Lipase , Fermentação , Lipase/metabolismo , Óleo de Palmeira , Penicillium
19.
Biotechnol Appl Biochem ; 68(3): 538-546, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32438471

RESUMO

The present study aimed at preparing three biocatalysts via physical adsorption of lipases from Candida rugosa (CRL), Mucor javanicus, and Candida sp. on a hydrophobic and mesoporous support (Diaion HP-20). These biocatalysts were later applied to the synthesis of aromatic esters of apple peel and citrus (hexyl butyrate), apple and rose (geranyl butyrate), and apricot and pineapple (propyl butyrate). Scanning electron microscopy and gel electrophoresis confirmed a selective adsorption of lipases on Diaion, thus endorsing simultaneous immobilization and purification. Gibbs free energy (∆G) evinced the spontaneity of the process (-17.9 kJ/mol ≤ ∆G ≤ -5.1 kJ/mol). Maximum immobilized protein concentration of 30 mg/g support by CRL. This biocatalyst was the most active in olive oil hydrolysis (hydrolytic activity of 126.0 ± 2.0 U/g) and in the synthesis of aromatic esters. Maximum conversion yield of 89.1% was attained after 150 Min for the synthesis of hexyl butyrate, followed by the synthesis of geranyl butyrate (87.3% after 240 Min) and propyl butyrate (80.0% after 150 Min). CRL immobilized on Diaion retained around 93% of its original activity after six consecutive cycles of 150 Min for the synthesis of hexyl butyrate.


Assuntos
Enzimas Imobilizadas/metabolismo , Ésteres/metabolismo , Hidrocarbonetos Aromáticos/metabolismo , Lipase/metabolismo , Mucor/enzimologia , Saccharomycetales/enzimologia , Enzimas Imobilizadas/química , Ésteres/química , Hidrocarbonetos Aromáticos/química , Interações Hidrofóbicas e Hidrofílicas , Lipase/química , Tamanho da Partícula , Propriedades de Superfície
20.
Angew Chem Int Ed Engl ; 60(34): 18454-18460, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34097781

RESUMO

Herein, we report a KIO4 -mediated, sustainable and chemoselective approach for the one-pot C(sp2 )-H bond hydroxymethylation or methylenation of imidazo-heteroarenes with formaldehyde, generated in situ via the oxidative cleavage of ethylene glycol or glycerol (renewable reagents) through the Malaprade reaction. In the presence of ethylene glycol, a series of 3-hydroxymethyl-imidazo-heteroarenes was obtained in good to excellent yields. These compounds are important intermediates to access pharmaceutical drugs, e.g., Zolpidem. Furthermore, by using glycerol, bis(imidazo[1,2-a]pyridin-3-yl)methane derivatives were selectively obtained in good to excellent yields.

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