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1.
Int J Biol Macromol ; 267(Pt 1): 131444, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38588840

RESUMO

Ramie bone (RB), an agricultural waste generated in the textile industry, is a vastly productive renewable natural resource with the potential to be used as a source of cellulose. In this study, ramie bone cellulose (RB-CE) was obtained in one step using a simple and ecologically friendly hydrogen peroxide-citric acid (HPCA) treatment procedure that avoided the use of halogenated reagents and strong acids while also streamlining the treatment processes. Various analytical methods were used to investigate the chemical composition and structure, crystallinity, morphology, thermal properties, surface area and hydration properties of cellulose separated at different treatment temperatures. HPCA successfully removed lignin and hemicellulose from RB, according to chemical composition analysis and FTIR. RB-CE had a type I cellulose crystal structure, and the crystallinity improved with increasing treatment temperature, reaching 72.51 % for RB-CE90. The RB-CE showed good thermal stability with degradation temperatures ranging from 294.2 °C to 319.1 °C. Furthermore, RB-CE had a high water/oil binding capacity, with RB-CE90 having WHC and OBC of 9.68 g/g and 7.24 g/g, respectively. The current work serves as a model for the environmentally friendly and convenient extraction of cellulose from biomass, and the cellulose obtained can be employed in the field of food and composite materials.


Assuntos
Celulose , Peróxido de Hidrogênio , Celulose/química , Peróxido de Hidrogênio/química , Osso e Ossos/química , Química Verde/métodos , Animais , Temperatura , Lignina/química , Lignina/isolamento & purificação , Água/química
2.
Int J Biol Macromol ; 268(Pt 1): 131479, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38608990

RESUMO

The huge demand for natural fibers necessitates the search for non-traditional bioresources including invasive species which are deteriorating the ecosystem and biodiversity. The study aims to utilize Pueraria montana weed for the extraction of lignocellulosic fiber using both traditional (water retting) and chemical extraction methods to determine the better extraction method. Chemically extracted fiber showed 17.09 g/tex bundle strength whereas water-extracted fiber showed 11.7 g/tex bundle strength. Therefore, chemical extraction method was chosen for fiber isolation by optimization of reaction conditions using Box Behnken Design. Based on the design, optimal conditions obtained were 1 % w/v NaOH, 0.75 % v/v H2O2, and 3 days retting time. Solid-state NMR illustrated the breakdown of hemicellulose linkages at 25.89 ppm. FTIR revealed the disappearance of C=O groups of hemicellulose at 1742 cm-1. TGA demonstrated thermal stability of chemically treated fiber up to 220 °C and activation energy of 60.122 KJ/mol. XRD evidenced that chemically extracted fiber has a crystallinity index of 71.1 % and a crystal size of 2 nm. Thus P. montana weed holds potential for the isolation of natural fiber as its chemical composition and properties are comparable to commercial lignocellulosic fibers. The study exemplifies the transformation of weed to a bioresource of natural fibers.


Assuntos
Lignina , Pueraria , Lignina/química , Lignina/isolamento & purificação , Pueraria/química , Controle de Plantas Daninhas/métodos , Polissacarídeos/química , Polissacarídeos/isolamento & purificação
3.
J Ethnopharmacol ; 289: 115060, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35121049

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Urtica fissa E. Pritz. are important herbs and have been traditionally used as ethnic medicine to treat rheumatism, inflammation, diabetes, and benign prostatic hyperplasia by the Han, Uighur, and other minorities in China, and also as an aphrodisiac in Uighur medicine. AIMS OF THE STUDY: To determine the effect and potential mechanism of 3, 4-divanillyltetrahydrofuran (DVTF), one of the main active components isolated from U. fissa on hypogonadism in diabetic mice. MATERIALS AND METHODS: The active compound DVTF was extracted and separated from the roots of U. fissa and identified using mass spectrometry and nuclear magnetic resonance spectroscopy. A mouse model of diabetes was established using high fat and sugar diet combined with streptozotocin. In the treatment groups, mice were received different doses of DVTF for 4 weeks. Fasting blood glucose levels, physiological and biochemical indices, and the mating behavior of DM mice were analyzed. Changes in testicular morphology were assessed using light microscopy and transmission electron microscopy. The expression of testosterone synthesis-related signaling proteins was detected using western blotting. Molecular docking was used to determine the binding ability of DVTF to Nur77. RESULTS: In diabetic mice, body weight and fasting blood glucose levels decreased. Mating behavior, including mount latency, mount number, and intromission number, was improved following DVTF treatment. Plasma total testosterone, free testosterone, and insulin resistance were positively associated with the recovery of testicular pathological structures in diabetic mice. DVTF treatment increased the expression of Nur77, StAR, and P450scc in the testes of diabetic mice. DVTF and Nur77 formed chemical bonds at five sites. CONCLUSION: As one of the main active components of U. fissa, DVTF exert potential therapeutic effects on testicular injury and hypogonadism caused by diabetes through activating the expression of Nur77 and testosterone synthesis related proteins. Our result will provide new insight for the clinical application of Urtica fissa E. Pritz., especially DVTF, as a potential drug candidate in the treatment of hypogonadism in diabetes.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Furanos/farmacologia , Hipogonadismo/tratamento farmacológico , Lignina/farmacologia , Urticaceae/química , Animais , Diabetes Mellitus Experimental/complicações , Feminino , Furanos/isolamento & purificação , Regulação da Expressão Gênica/efeitos dos fármacos , Hipogonadismo/etiologia , Resistência à Insulina , Lignina/isolamento & purificação , Masculino , Camundongos , Camundongos Endogâmicos ICR , Simulação de Acoplamento Molecular , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Comportamento Sexual Animal/efeitos dos fármacos , Disfunções Sexuais Fisiológicas/tratamento farmacológico , Disfunções Sexuais Fisiológicas/etiologia , Estreptozocina , Testículo/efeitos dos fármacos , Testosterona/sangue
4.
Int J Biol Macromol ; 194: 204-212, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34863836

RESUMO

As the vital renewable feedstock originated from carbon-neutral resources, due to prominent aromaticity lignin owns the potential to produce high value-added products. Multi-functional lignin valorization demands efficient lignin extraction at milder conditions to keep its structure intact to substitute petroleum-based reactants. Lignin extraction severity (LES) is considered as the primary factor affecting the structure of extracted lignin and ultimately determines its applications. Except for the LES, the selection of suitable reagents for lignin extraction concerned with specific applications is crucially important. To explore the influence of different reagents, this study focused on lignin extraction employing the commonly used strong acids at the same LES. Four lignin preparations were extracted using 80% aqueous dioxane with the addition of H2O (L1), HCl, H2SO4 and HNO3 (pH = 1.30 ± 0.01 L2, L3 and L4, respectively). Analytical high-sensitive NMR (31P and 2D-HSQC) together with other characterizations (FTIR and GPC) were successfully employed and quantified while unveiling the structural heterogeneity among extracted lignin preparations. At the same LES, different reagents yielded lignin with varying structural characteristics and were potentially suitable for different applications.


Assuntos
Ácidos/química , Lignina/química , Fracionamento Químico/métodos , Lignina/isolamento & purificação , Estrutura Molecular , Peso Molecular , Análise Espectral
5.
Int J Biol Macromol ; 192: 498-505, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34619280

RESUMO

Acanthopanax senticosus has been used to extract active products. However, abundant Acanthopanax senticosus residues (ASR), which contain plenty of lignin are discarded after extraction. An appropriate extraction method should be chosen to obtain the lignin with such desirable properties. Thus, this study investigated the effect of alkali, milled wood, deep eutectic solvent and ethanol methods on the lignin. Lignin obtained from different extraction methods were characterized, yields, chemical structure, thermal behavior, molecular weight and phenolic content were evaluated. The results show that the process of lignin acquisition has a great influence on the properties of lignin. Moreover, the multifarious functional groups exist in lignin macromolecules, such as phenolic, ether groups and other chromophores, conferred good UV resistance to lignin. Among them, the lignin from alkali method has the most phenolic-OH groups and smallest molecular weight result in a good UV-resistant, the SPF value achieves 2.39 at 1% AL content, the alkali method was the best way to make sunscreen blended with cream take various factors into consideration. This study used lignin as a bioactive ingredient to provide UV-resistant property to sunscreen formulations. Furthermore, lignin extracted from Acanthopanax senticosus residue provides a new application for the treatment of herb residue waste.


Assuntos
Fracionamento Químico/métodos , Eleutherococcus/química , Lignina/química , Lignina/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Solventes Eutéticos Profundos/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Compostos Fitoquímicos/química , Açúcares/química
6.
Int J Biol Macromol ; 193(Pt A): 64-70, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34688675

RESUMO

Pure deep eutectic solvents (DESs) system of choline chloride (ChCl)/Lactic acid (Lac) were demonstrated to be an effective strategy for extraction of lignin. In this study, two kinds of different promising solid acid (SA) with DESs were designed to promote the pretreatment of lignocellulose. The SA of phosphotungstic acid (H3O40PW12) and iron bromide (FeBr3) were introduced into DESs to extract poplar wood lignin and evaluate the antioxidant activity. It was found that 82.2% and 80.9% of lignin were obtained from poplar wood under H3O40PW12-ChCl/Lac acid and FeBr3-choline ChCl/Lac system with 4 h and 8 h, respectively. The lignin fractions with a high purity (>89%), low molecular weight (Mw 1800-2000 g/mol). Besides, the antioxidant activities of lignin fractions were better than butyl hydroxyanisole (BHA). Therefore, DES lignin has prominent antioxidant activity and could developed a potential natural cosmetics and food packaging.


Assuntos
Colina/química , Lignina/isolamento & purificação , Populus/química , Solventes/química , Madeira/química , Hidrólise
7.
Chem Biodivers ; 18(10): e2100431, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34496126

RESUMO

Cactaceae family has heterogeneity in the accumulation of lignocellulose due to the diversity of shapes and anatomy of the wood. Most studies focus on fibrous and dimorphic species; but the non-fibrous species are poorly studied. The aims of this work were to analyze the syringyl/guaiacyl ratio of lignin and its distribution in secondary xylem, especially in non-fibrous species. The syringyl/guaiacyl (S/G) ratio was quantified from 34 species of cacti by nitrobenzene oxidation of free-extractive wood. The distribution of lignocellulose in wood sections stained with safranin O/fast green was determined with epifluorescence microscopy. The S/G ratio was heterogeneous; most of the non-fibrous species had a higher percentage of syringyl, while the fibrous ones accumulate guaiacyl. Fluorescence emission showed that vessel elements and wide-band tracheids had similar tonalities. It is hypothesized that the presence of a higher percentage of syringyl in most cacti is part of the defense mechanism against pathogens, which together with the succulence of the stem represent adaptations that contribute to survival in their hostile environments.


Assuntos
Cactaceae/química , Lignina/química , Xilema/química , Lignina/isolamento & purificação , Filogenia
8.
Int J Biol Macromol ; 187: 903-910, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34343583

RESUMO

Lignocellulose including cellulose, lignin, and hemicellulose could be extracted from wood, and has been used to prepare carbon electrode. However, complicated extraction greatly increases preparation cost. To achieve maximum utilization of lignocellulose and avoid complicated extraction, wood with porous structure and good mechanical strength is used as carbon precursor. Additionally, chemical activation is commonly used to create micropores to provide high capacitance, but it brings in natural structure destruction, and generation of wastewater during pickling. Moreover, to achieve desirable energy density, multi-step strategy with long duration is required for loading active materials on carbonized lignocellulose (CL). Herein, a one-step method is developed to prepare a free-standing hybrid CL electrode (CLE) by using Lewis acid in three aspects: (1) as structure protection agent, (2) as activating agent, (3) as active materials donor, which bypasses pickling and further avoids the generation of wastewater. Additionally, natural vessels in wood can not only provide large space for active materials loading, but also act as rapid ions diffusion way, simultaneously confining active materials detachment. Benefiting from the synergistic effect of porous structure and Lewis acid, this work not only makes full utilization of lignocellulose, but also makes CLE exhibit excellent performance in hybrid oxide supercapacitor.


Assuntos
Fontes de Energia Elétrica , Eletrodos , Lignina/química , Óxidos/química , Populus , Energia Renovável , Madeira , Carbono/química , Difusão , Capacitância Elétrica , Desenho de Equipamento , Íons , Cinética , Lignina/isolamento & purificação , Populus/química , Porosidade , Propriedades de Superfície , Madeira/química
9.
Carbohydr Polym ; 269: 118321, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34294333

RESUMO

This study investigated the process intensification strategies for the pretreatment of Radiata Pine with the green deep eutectic solvent (DES) system composed of benzyltrimethylammonium chloride/formic acid (BTMAC/FA). The results showed that DES pretreatment drastically improved the delignification and hemicelluloses-removal capacity. The conducted process acceptably remained most of the cellulose in pretreated biomass (88.3%-91.8%). Benefiting from the overcoming of recalcitrance, the enzymatic digestibility of pretreated residues reached 92.4%. The efficient conversion was mainly ascribed to the lignin and hemicelluloses co-extraction. Meanwhile, the lignin yield and enzymatic saccharification was still largely maintained after five reuses. Further structural characteristics of lignin nanoparticles revealed that the lignin possessed high purity (95.19-97.51%), medium molecular weight (9600 to 6495 g/mol), and low polydispersity (ca 2.0), which was attributed to cleavage of ether bonds in lignin as well as linkages between lignin and hemicelluloses. Overall, this study illustrated that DES pretreatment was promising to achieve an efficient fractionation of woody biomass into fermentable glucose and high-quality lignin.


Assuntos
Lignina/química , Nanopartículas/química , Pinus/química , Solventes/química , Celulase/química , Formiatos/química , Hidrólise , Lignina/isolamento & purificação , Peso Molecular , Tamanho da Partícula , Compostos de Amônio Quaternário/química
10.
Int J Biol Macromol ; 187: 462-470, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34280451

RESUMO

In this study, three lignin fractions F1, F2, and F3 were obtained from eucalyptus kraft lignin (EKL) by solvent extraction with ethyl acetate, acetone, and acetone/water. The antioxidant activity of these lignin fractions were measured and evaluated by using the DPPH radical scavenging activity, ABTS radical cation scavenging activity and ferric reducing antioxidant power analysis. These lignin fractions were also characterized by applying Gel permeation chromatography, Fourier transform infrared, 31P NMR and 2D HSQC NMR techniques. The three different lignin fractions had rather different average molecular sizes, as well as different phenolic and methoxy functional contents. The ethyl acetate fraction (F1) with the lowest average molecular weight (2342 g/mol) and the highest phenolic hydroxyl content (4.2457 mmol/g) and methoxy groups (6.2714 mmol/g) showed high homogeneity and the highest antioxidant activity. Its DPPH scavenging activity, ABTS+ scavenging activity, and ferric reducing the antioxidant power were 68.67%, 75.57%, and 91.89 µmol/g, respectively. Moreover, the antioxidant activity of F1 and F2 was found to be higher than that of butylated hydroxytoluene. Therefore, solvent extraction was shown to be an effective way to separate lignin fractions with high homogeneity, high antioxidant activity, which could lead to application of lignin with higher value.


Assuntos
Antioxidantes/química , Eucalyptus , Lignina/química , Solventes/química , Acetatos/química , Acetona/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Benzotiazóis/química , Compostos de Bifenilo/química , Fracionamento Químico , Eucalyptus/química , Lignina/isolamento & purificação , Lignina/farmacologia , Estrutura Molecular , Peso Molecular , Picratos/química , Solubilidade , Relação Estrutura-Atividade , Ácidos Sulfônicos/química , Água/química
11.
Molecules ; 26(14)2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34299398

RESUMO

Rice straw hydrotropic lignin was extracted from p-Toluene sulfonic acid (p-TsOH) fractionation with a different combined delignification factor (CDF). Hydrotropic lignin characterization was systematically investigated, and alkaline lignin was also studied for the contrast. Results showed that the hydrotropic rice straw lignin particle was in nanometer scopes. Compared with alkaline lignin, the hydrotropic lignin had greater molecular weight. NMR analysis showed that ß-aryl ether linkage was well preserved at low severities, and the unsaturation in the side chain of hydrotropic lignin was high. H units and G units were preferentially degraded and subsequently condensed at high severity. High severity also resulted in the cleavage of part ß-aryl ether linkage. 31P-NMR showed the decrease in aliphatic hydroxyl groups and the increasing carboxyl group content at high severity. The maximum weight loss temperature of the hydrotropic lignin was in the range of 330-350 °C, higher than the alkaline lignin, and the glass conversion temperature (Tg) of the hydrotropic lignin was in the range of 107-125 °C, lower than that of the alkaline lignin. The hydrotropic lignin has high ß-aryl ether linkage content, high activity, nanoscale particle size, and low Tg, which is beneficial for its further valorization.


Assuntos
Lignina/química , Lignina/isolamento & purificação , Oryza/química , Água/química , Biomassa , Fracionamento Químico , Hidrólise , Lignina/análise
12.
Chem Rec ; 21(7): 1631-1665, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34132038

RESUMO

Nanotechnology has transformed the world with its diverse applications, ranging from industrial developments to impacting our daily lives. It has multiple applications throughout financial sectors and enables the development of facilitating scientific endeavors with extensive commercial potentials. Nanomaterials, especially the ones which have shown biomedical and other health-related properties, have added new dimensions to the field of nanotechnology. Recently, the use of bioresources in nanotechnology has gained significant attention from the scientific community due to its 100 % eco-friendly features, availability, and low costs. In this context, jute offers a considerable potential. Globally, its plant produces the second most common natural cellulose fibers and a large amount of jute sticks as a byproduct. The main chemical compositions of jute fibers and sticks, which have a trace amount of ash content, are cellulose, hemicellulose, and lignin. This makes jute as an ideal source of pure nanocellulose, nano-lignin, and nanocarbon preparation. It has also been used as a source in the evolution of nanomaterials used in various applications. In addition, hemicellulose and lignin, which are extractable from jute fibers and sticks, could be utilized as a reductant/stabilizer for preparing other nanomaterials. This review highlights the status and prospects of jute in nanotechnology. Different research areas in which jute can be applied, such as in nanocellulose preparation, as scaffolds for other nanomaterials, catalysis, carbon preparation, life sciences, coatings, polymers, energy storage, drug delivery, fertilizer delivery, electrochemistry, reductant, and stabilizer for synthesizing other nanomaterials, petroleum industry, paper industry, polymeric nanocomposites, sensors, coatings, and electronics, have been summarized in detail. We hope that these prospects will serve as a precursor of jute-based nanotechnology research in the future.


Assuntos
Celulose/química , Corchorus/química , Lignina/química , Nanocompostos/química , Nanotecnologia/tendências , Animais , Catálise , Celulose/isolamento & purificação , Humanos , Lignina/isolamento & purificação , Nanopartículas Metálicas/química , Oxirredução
13.
Int J Biol Macromol ; 181: 752-761, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-33798581

RESUMO

Lignin-carbohydrate complexes (LCC) have shown great potential as biocompatible antioxidants. But it is difficult to isolate LCC efficiently from lignocellulose by traditional Solid-Liquid Extraction method (SLE), which is blamed to the innate bioimpedance caused by the complex supramolecular structure of the lignocellulose, and a great mass transferring resistance between the extracting solution and solid lignocellulose. To release these restrictions above and improve the efficiency of LCC isolation, a modified isolating method named Liquid-Liquid Extraction (LLE) was proposed, in which ball-milled wheat stalk was dissolved in lithium chloride/dimethyl sulfoxide (LiCl/DMSO) solution, then regenerated by dioxane aqueous to extract LL-LCCs. The effect of the LLE on the LCC isolating was evaluated and results showed that both the total yield and antioxidant activity of LL-LCCs were higher than that of control group. It proved the dissolution of wheat stalk in LiCl/DMSO solution could reduce the mass transfer resistance during the extraction. Due to the catalyzation of LiCl as Lewis acid, LL-LCCs had lower molecular weight but more phenolic hydroxyl groups and higher S/G ratios. These factors of LL-LCCs resulted in greater free-radical scavenging ability than control sample. The modified isolation protocol could facilitate the isolation and utilization of LCCs as a free-radical scavenger.


Assuntos
Antioxidantes/farmacologia , Carboidratos/isolamento & purificação , Dimetil Sulfóxido/química , Lignina/isolamento & purificação , Cloreto de Lítio/química , Solventes/química , Compostos de Bifenilo/química , Carboidratos/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Sequestradores de Radicais Livres/farmacologia , Peso Molecular , Picratos/química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Triticum/química
14.
Int J Biol Macromol ; 183: 101-109, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33905799

RESUMO

Nanocellulose isolation from lignocellulose is a tedious and expensive process with high energy and harsh chemical requirements, primarily due to the recalcitrance of the substrate, which otherwise would have been cost-effective due to its abundance. Replacing the chemical steps with biocatalytic processes offers opportunities to solve this bottleneck to a certain extent due to the enzymes substrate specificity and mild reaction chemistry. In this work, we demonstrate the isolation of sulphate-free nanocellulose from organosolv pretreated birch biomass using different glycosyl-hydrolases, along with accessory oxidative enzymes including a lytic polysaccharide monooxygenase (LPMO). The suggested process produced colloidal nanocellulose suspensions (ζ-potential -19.4 mV) with particles of 7-20 nm diameter, high carboxylate content and improved thermostability (To = 301 °C, Tmax = 337 °C). Nanocelluloses were subjected to post-modification using LPMOs of different regioselectivity. The sample from chemical route was the least favorable for LPMO to enhance the carboxylate content, while that from the C1-specific LPMO treatment showed the highest increase in carboxylate content.


Assuntos
Betula/metabolismo , Celulase/metabolismo , Celulose/metabolismo , Lignina/metabolismo , Oxigenases de Função Mista/metabolismo , Nanofibras , Biomassa , Celulase/genética , Celulose/isolamento & purificação , Hidrólise , Lacase/genética , Lacase/metabolismo , Lignina/isolamento & purificação , Oxigenases de Função Mista/genética , Phanerochaete/enzimologia , Phanerochaete/genética , Saccharomycetales/enzimologia , Saccharomycetales/genética , Sordariales/enzimologia , Sordariales/genética , Especificidade por Substrato , Xilosidases/genética , Xilosidases/metabolismo
15.
Int J Biol Macromol ; 180: 286-298, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33737189

RESUMO

Lignins are phenolic macromolecules that have several applications. In this work, we examine some biological activities of a lignin-like macromolecule isolated from the Crataeva tapia leaves, not yet studied to evaluate its potential applications in medicinal and cosmetic formulations. Lignin was obtained by alkaline delignification and its physical-chemical characterization was made by means of FT-IR, UV-Vis, NMR spectroscopy, elementary analysis, molecular mass determination and thermal analysis. Lignin is of the GSH type, with levels of hydrogen (5.10%), oxygen (27.18%), carbon (67.60%), nitrogen (0.12%) and phenolic content of 189.6 ± 9.6 mg GAE/g. In addition, it is a thermally stable macromolecule with low antioxidant activity. Cytotoxicity and cytokine production were assessed by flow cytometry. The photoprotective activity was evaluated by adding different concentrations of lignin to a commercial cream. Lignin was not cytotoxic, it stimulated the production of TNF-α, IL-6 and IL-10 and did not promote a significant change in nitric oxide levels. In addition, this macromolecule was able to promote increased absorption of ultraviolet light from a commercial cream. These results reinforce the ethnopharmacological use of C. tapia leaves and suggest the need for further studies to determine the potential medicinal and cosmetic applications (sunscreen) of lignin from C. tapia leaves.


Assuntos
Antioxidantes/química , Capparaceae/química , Lignina/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Protetores Solares/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Doadores de Sangue , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cosméticos/química , Citocinas/biossíntese , Humanos , Lignina/isolamento & purificação , Lignina/farmacologia , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Peso Molecular , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Fenóis/análise , Extratos Vegetais/isolamento & purificação , Transdução de Sinais/efeitos dos fármacos , Absorção Cutânea/efeitos dos fármacos , Protetores Solares/isolamento & purificação , Protetores Solares/farmacologia , Raios Ultravioleta
16.
Int J Biol Macromol ; 174: 254-262, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33529632

RESUMO

Fabricating lignin-based carbon nanofibers (LCNFs) with the lignin in spent coffee grounds (SCG) as raw material which are disposed as waste amounting to millions tons annual is benefit to promote economy and environmental protection. However, due to the heterogeneity and complex three-dimensional structure, the mechanic property is very poor. In this study, we propose a fractionating pretreatment method to overcome the above problems by regulating the structure of SCG lignin in which high-performance LCNFs were fabricated. On one hand, the linear structure of SCG lignin was optimized to fit the raw material of LCNFs by tuning the content of ß-O-4 and C5-substituted condensed phenolic compounds. On the other hand, the carboxyl as the hydrophilic groups was removed so as to promote the mixing of lignin and polyacrylonitrile (PAN, blending agent) in organic solvents. Additionally, the heterogeneity was reduced by screening large molecular weight SCG lignin with low polydispersity index (PDI). Fortunately, with 1:1 mass ratio of the above fractionated lignin and PAN as substrate, the LCNFs could reach to comparable mechanic properties with those of pure PAN CNFs. This work can provide a new way to not only promote the utilization of SCG lignin but also accelerate the development of LCNFs.


Assuntos
Carbono/química , Café/química , Lignina/isolamento & purificação , Resinas Acrílicas/química , Fracionamento Químico , Resíduos Industriais/análise , Lignina/química , Nanofibras/química , Temperatura
17.
Int J Biol Macromol ; 177: 294-305, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33607141

RESUMO

Lignocellulosic biomass is a renewable and sustainable feedstock, mainly composed of cellulose, hemicellulose, and lignin. Lignin, as the most abundant natural aromatic polymer occurring on Earth, has great potential to produce value-added products. However, the isolation of highly pure lignin from biomass requires the use of efficient methods during lignocellulose fractionation. Therefore, in this work, novel acidic deep eutectic solvents (DESs) were prepared, characterized and screened for lignin extraction from maritime pine wood (Pinus pinaster Ait.) sawdust. The use of cosolvents and the development of new DES were also evaluated regarding their extraction and selectivity performance. The results show that an 1 h extraction process at 175 °C, using a novel DES composed of lactic acid, tartaric acid and choline chloride, named Lact:Tart:ChCl, in a molar ratio of 4:1:1, allows the recovery of 95 wt% of the total lignin present in pine biomass with a purity of 89 wt%. Such superior extraction of lignin with remarkable purity using a "green" solvent system makes this process highly appealing for future large-scale applications.


Assuntos
Colina/química , Ácido Láctico/química , Lignina/isolamento & purificação , Pinus/química , Tartaratos/química , Madeira/química , Lignina/química , Solventes/química
18.
Molecules ; 26(4)2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33557106

RESUMO

Aiming to fulfil the sustainability criteria of future biorefineries, a novel biomass pretreatment combining natural deep eutectic solvents (NaDESs) and microwave (MW) technology was developed. Results showed that NaDESs have a high potential as green solvents for lignin fractionation/recovery and sugar release in the following enzymatic hydrolysis. A new class of lignin derived NaDESs (LigDESs) was also investigated, showing promising effects in wheat straw delignification. MW irradiation enabled a fast pretreatment under mild condition (120 °C, 30 min). To better understand the interaction of MW with these green solvents, the dielectric properties of NaDESs were investigated. Furthermore, a NaDES using the lignin recovered from biomass pretreatment as hydrogen bond donor was prepared, thus paving the way for a "closed-loop" biorefinery process.


Assuntos
Biomassa , Lignina/química , Lignina/isolamento & purificação , Micro-Ondas , Solventes/química , Química Verde
19.
Int J Biol Macromol ; 175: 304-312, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33516854

RESUMO

Steam explosion can be used to pretreat lignocellulosic materials to decrease energy and chemical consumption during pulping to obtain environmentally friendly lignin and to improve lignin yield without changing its structure. The objective of this study was to evaluate the extraction of lignin from oil palm mesocarp fibers and sugarcane bagasse using steam explosion pretreatment followed by acetosolv. The biomasses were pretreated at 168 °C for a reaction time of 10 min. Steam explosion combined with acetosolv at lower severities was also carried out. Steam explosion followed by acetosolv increased the lignin yield by approximately 15% and 17% in oil palm mesocarp fibers and sugarcane bagasse, respectively. In addition, steam explosion decreased the reaction time of acetosolv four-fold while maintaining the lignin yield from sugarcane bagasse. Similar results were not obtained for oil palm mesocarp. High-purity and high-quality lignins were obtained using steam explosion pretreatment with structural characteristics similar to raw ones. Sugarcane bagasse lignin seems to be a better option for application in material science due its higher lignin yield and higher thermal stability. Our findings demonstrate that steam explosion is efficient for improving lignin yield and/or decreasing pulping severity.


Assuntos
Celulose/isolamento & purificação , Lignina/isolamento & purificação , Óleo de Palmeira/isolamento & purificação , Ácido Acético/química , Biomassa , Biotecnologia/métodos , Celulose/química , Etanol , Hidrólise , Lignina/química , Extratos Vegetais/isolamento & purificação , Saccharum/química , Vapor
20.
N Biotechnol ; 60: 189-199, 2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33130025

RESUMO

Modification of lignin with poly(ε-caprolactone) is a promising approach to valorize industrial low-value lignins and to advance the bioeconomy. We have synthesized lignin grafted poly(ε-caprolactone) (lignin-g-PCL) copolymers via ring-opening polymerization of ε-caprolactone with different types of lignins of varying botanical sources (G-type pine lignin, S/G-type poplar lignin, and C-type Vanilla seeds lignin) and lignin extraction methods (Kraft and ethanol organosolv pulping). The lignin-g-PCL copolymer showed remarkably improved compatibility and dispersion in acetone, chloroform, and toluene in comparison to non-modified lignins. The structure and thermal properties of the lignin-g-PCL were investigated using Fourier-transform infrared spectroscopy (FTIR), 31P nuclear magnetic resonance (NMR), 2D heteronuclear single quantum correlation (HSQC) NMR, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). We have found that all the technical lignins were reactive to the copolymerization reaction regardless of their plant source and isolation methods. The molecular weights of the synthesized lignin-g-PCL copolymers were positively correlated with the content of aliphatic lignin hydroxyls, suggesting that the copolymerization reaction tends to occur preferentially at the aliphatic hydroxyls rather than the phenolic hydroxyls of lignin. Thermal analyses of the lignin-g-PCL copolymers were studied, and in general, a reduction of melting temperature and crystallinity percentage in comparison to the neat PCL was observed. However, the thermal behavior of lignin-g-PCL copolymers varied depending on the lignin feedstocks employed in the copolymerization reaction.


Assuntos
Lignina/biossíntese , Plantas/química , Poliésteres/metabolismo , Biomassa , Lignina/química , Lignina/isolamento & purificação , Conformação Molecular , Plantas/metabolismo , Poliésteres/química , Polimerização
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