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Cellulose and lignin, sourced from biomass, hold potential for innovative bioprocesses and biomaterials. However, traditional fractionation and purification methods often rely on harmful chemicals and high temperatures, making these processes both hazardous and costly. This study introduces a sustainable approach for fractionating acacia wood, focusing on both cellulose and lignin extraction using a deep eutectic solvent (DES) composed of choline chloride (ChCl) and levulinic acid (LA). A design of experiment was employed for the optimization of the most relevant fractionation parameters: time and temperature. In the case of the lignin, both parameters were found to be significant variables in the fractionation process ( p -values of 0.0128 and 0.0319 for time and temperature, respectively), with a positive influence. Likewise, in the cellulose case, time and temperature also demonstrated a positive effect, with p -values of 0.0103 and 0.028, respectively. An optimization study was finally conducted to determine the maximum fractionation yield of lignin and cellulose. The optimized conditions were found to be 15% ( w / v ) of the wood sample in 1:3 ChCl:LA under a treatment temperature of 160 °C for 8 h. The developed method was validated through repeatability and intermediate precision studies, which yielded a coefficient of variation lower than 5%. The recovery and reuse of DES were successfully evaluated, revealing remarkable fractionation yields even after five cycles. This work demonstrates the feasibility of selectively extracting lignin and cellulose from woody biomass using a sustainable solvent, thus paving the way for valorization of invasive species biomass.

Introduction: Lignin has great potential as the most abundant renewable phenolic polymer. Studies have shown that lignin structure varies depending on different sources and different extraction methods. However, there are few studies on lignin in kudzu root residue., Objectives: The aim of the study was to explore optimal extraction conditions of Pueraria lobata residue lignin (PLL) with deep eutectic solvents (DESs) and characterise the structure and morphology of PLL., Methods: Firstly, the chemical composition of kudzu root residue was determined by the Van-soest method. Then, betaine was used as hydrogen bond acceptor (HBA), nine kinds of common acids and alcohol were selected as hydrogen bond donor (HBD) to synthesise a DES to extract lignin from kudzu root residue. The influence of conditions on the extraction of PLL was explored by a betaine-based DES according to a single-factor experiment, and then the best process of PLL extraction was determined by an orthogonal experiment. Finally, the morphology and structure of PLL were analysed by scanning electron microscope (SEM), thermogravimetric analysis (TGA), gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), and NMR., Results: Cellulose, hemicellulose, lignin, and ash content in kudzu root residue were 41.13%, 16.39%, 25.03%, and 0.41%, respectively. When the DES consisted of betaine and formic acid, the solid-liquid ratio was 1:45, the extraction time was 5.5 h at 160°C, the extraction yield of lignin was 89.29%, and the purity was 83.01%. PLL was composed of interconnected spherical particles with good thermal stability and narrow polydispersity index (PDI) distribution. FTIR and 2D-heteronuclear singular quantum correlation (HSQC) NMR illustrated that PLL was a typical G-type and S-type lignin., Conclusion: This study would fill the gap of research on lignin in kudzu root residue and provide a theoretical reference for the utilisation of lignin in kudzu roots as well as a new thinking for the recycling of kudzu root resources., (© 2024 John Wiley & Sons Ltd.)

Lignanoids are an active ingredient exerting powerful antioxidant and anti-inflammatory effects in the treatment of many diseases. In order to improve the efficiency of the resource utilization of traditional Chinese medicine waste, Magnolia officinalis Rehder & E.H.Wilson residue (MOR) waste biomass was used as raw material in this study, and a series of deep eutectic solvents (ChUre, ChAce, ChPro, ChCit, ChOxa, ChMal, ChLac, ChLev, ChGly and ChEG) were selected to evaluate the extraction efficiency of lignanoids from MORs. The results showed that the best conditions for lignanoid extraction were a liquid-solid ratio of 40.50 mL/g, an HBD-HBA ratio of 2.06, a water percentage of 29.3%, an extract temperature of 337.65 K, and a time of 107 min. Under these conditions, the maximum lignanoid amount was 39.18 mg/g. In addition, the kinetics of the extraction process were investigated by mathematic modeling. In our antioxidant activity study, high antioxidant activity of the lignanoid extract was shown in scavenging four different types of free radicals (DPPH, ·OH, ABTS, and superoxide anions). At a concentration of 3 mg/mL, the total antioxidant capacity of the lignanoid extract was 1.795 U/mL, which was equal to 0.12 mg/mL of V c solution. Furthermore, the antibacterial activity study found that the lignanoid extract exhibited good antibacterial effects against six tested pathogens. Among them, Staphylococcus aureus exerted the strongest antibacterial activity. Eventually, the correlation of the lignanoid extract with the biological activity and physicochemical properties of DESs is described using a heatmap, along with the evaluation of the in vitro hypoglycemic, in vitro hypolipidemic, immunomodulatory, and anti-inflammatory activity of the lignanoid extract. These findings can provide a theoretical foundation for the extraction of high-value components from waste biomass by deep eutectic solvents, as well as highlighting its specific significance in natural product development and utilization.

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., Competing Interests: Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of the manuscript entitled., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Lignin is an abundant natural biopolymer found in plant cell walls. Lignin can come from tinctorial plants, whose residual biomass after dye extraction was typically discarded as waste. The main objective of this study was to extract lignin from the residual biomass of Reseda luteola L. using an organosolv process and to optimize the extraction conditions. The extracted lignin was characterized, and its potential applications as an antimicrobial, anti-oxidant, and anti-UV agent were investigated. Response surface methodology based on a Box-Behnken design was employed to optimize the lignin extraction conditions (organic acid concentration, material-to-liquid ratio, extraction time). The extracted lignin was comprehensively characterized using NMR, FTIR, XRD, SEM-EDX, TGA, DSC, and UV-Vis techniques. The optimal extraction conditions yielded a remarkably high lignin recovery of 62.41 % from the plant waste, which was rarely achieved for non-wood plants in previous works. The extracted lignin exhibited excellent thermal stability and radical scavenging anti-oxidant activity but no significant antimicrobial effects. Treating wool fabrics with lignin nanoparticles substantially enhanced UV protection from the "good" to "excellent" category based on the UPF rating. This sustainable valorization approach converted abundant tinctorial plant waste into high-purity lignin with promising anti-oxidant and UV-blocking properties suitable for various applications., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests. We have no conflicts of interest to disclose., (Copyright © 2024 Elsevier B.V. All rights reserved.)

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 H 2 O 2 , 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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

As an environmentally friendly lignocellulosic biomass separation technology, hydrothermal pretreatment (HP) has a strong application prospect. However, the low separation efficiency is a main factor limiting its application. In this study, the poplar components were separated using HP with ferric chloride and pH buffer (HFB). The optimal conditions were ferric chloride concentration of 0.10 M, reaction temperature of 150 °C, reaction time of 15 min and pH 1.9. The separation of hemicellulose was increased 34.03 % to 77.02 %. The pH buffering resulted in the highest cellulose and lignin retention yields compared to ferric chloride pretreatment (FC). The high efficiency separation of hemicellulose via HFB pretreatment inhibited the degradation of xylose. The hydrolysate was effectively reused for five times. The fiber crystallinity index reached 60.05 %, and the highest C/O ratio was obtained. The results provide theoretical support for improving the efficiency of HP and promoting its application., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

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., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Nanocellulose is a renewable and biocompatible nanomaterial that evokes much interest because of its versatility in various applications. This study reports the production of nanocellulose from Agave gigantea (AG) fiber using the chemical-ultrafine grinding treatment. Chemical treatment (alkalization and bleaching) removed non-cellulose components (hemicellulose and lignin), while ultrafine grinding reduced the size of cellulose microfibrils into nanocellulose. From the observation of Transmission Electron Microscopy, the average diameter of nanocellulose was 4.07 nm. The effect of chemical-ultrafine grinding on the morphology and properties of AG fiber was identified using chemical composition, Scanning Electron Microscopy, X-ray Diffraction, Fourier Transform Infrared, and Thermogravimetric Analysis. The bleaching treatment increased the crystal index by 48.3% compared to raw AG fiber, along with an increase in the cellulose content of 20.4%. The ultrafine grinding process caused a decrease in the crystal content of the AG fiber. The crystal index affected the thermal stability of the AG fiber. The TGA results showed that AG fiber treated with bleaching showed the highest thermal stability compared to AG fiber without treatment. The FTIR analysis showed that the presence of CH vibrations from the ether in the fiber. After chemical treatment, the peaks at 1605 and 1243 cm -1 disappeared, indicating the loss of lignin and hemicellulose functional groups in AG fiber. As a result, nanocellulose derived from AG fiber can be applied as reinforcement in environmentally friendly polymer biocomposites., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The use of lignin is limited by its heterogeneity and complexity. This study was processed using different methods to obtain spruce milled wood lignin (SMWL), spruce kraft lignin (SKL), and spruce lignocresol (SLC) for comparative analysis of the structure and antioxidant activity. SMWL has a complete softwood lignin side-chains structure and lignin carbohydrate complexes. SKL contains fewer ether bonds, while more conjugate structures and condensed structures contribute to the color. However, the α-position of the lignin side chain eliminates most of the hydroxyl and ether bonds (β-O-4/α-OH, phenylcoumaran, and dibenzodioxocine structure) and effectively grafts p-cresol in the phase separation reaction. It not only inhibits the self-condensation of lignin, but also forms the 1,1-diarylpropane unit while protecting β-O-4 linkages from not breaking. Importantly, SLC has few conjugate structures that result in the lightest color among all lignin isolated. Besides, SLC has a high yield and contains trace carbohydrates, indicating that the phase separation method can achieve great amounts of purity separated lignin. The antioxidant activity of lignin was evaluated, results show that 85% of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals were scavenged at the end of 60 min. Owing to its unique color, structural properties, and continuous antioxidant activity, SLC has the potential to manufacture antioxidant cosmetics., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Biomass fractionation plays a major role in the search for competitive biorefineries, where the isolation and recovery of the three woody fractions is key. In this sense, we have used autohydrolyzed hemicellulose-free poplar as feedstock to compare two fractionation processes, organosolv and ionosolv, oriented to lignin recovery. The recovered lignins were then characterize by different techniques (NMR, GPC, TGA). Both treatments were tested at different temperatures to analyze temperature influence on lignin recovery and properties. The highest lignin recovery was obtained with the ionosolv process at 135 °C, reaching a solid yield of ~70%. Lignin characterization showed differences between both treatments. Lignins enriched in C-O linkages and G units were recovered with the organosolv process, where increasing temperature led to highly depolymerized lignins. However, lignins with higher C-C linkages and S units contents were obtained with the ionosolv process, producing more thermically stable lignins. In addition, increasing temperature caused lignin repolymerization when employing ionic liquids as solvents. Therefore, this work outlines the most important differences between ionosolv and organosolv processes for biomass fractionation, focusing on lignin recovery and its properties, which is the first step in order to valorize all biomass fractions., (Copyright © 2021 Elsevier B.V. All rights reserved.)

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 H 2 O (L1), HCl, H 2 SO 4 and HNO 3 (pH = 1.30 ± 0.01 L2, L3 and L4, respectively). Analytical high-sensitive NMR ( 31 P 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., (Copyright © 2021 Elsevier B.V. All rights reserved.)

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 (H 3 O 40 PW 12 ) and iron bromide (FeBr 3 ) 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 H 3 O 40 PW 12 -ChCl/Lac acid and FeBr 3 -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., (Copyright © 2021 Elsevier B.V. All rights reserved.)

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., (Copyright © 2021 Elsevier B.V. All rights reserved.)

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., (© 2021 Wiley-VHCA AG, Zurich, Switzerland.)

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., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

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, 31 P 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., (Copyright © 2021 Elsevier B.V. All rights reserved.)

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., (Copyright © 2021 Elsevier B.V. All rights reserved.)

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 (T o = 301 °C, T max = 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., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

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 β-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 β-aryl ether linkage. 31 P-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 (T g ) of the hydrotropic lignin was in the range of 107-125 °C, lower than that of the alkaline lignin. The hydrotropic lignin has high β-aryl ether linkage content, high activity, nanoscale particle size, and low T g , which is beneficial for its further valorization.

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., (© 2021 The Chemical Society of Japan & Wiley-VCH GmbH.)

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., Competing Interests: Declaration of competing interest We declare that we have no conflict interest., (Copyright © 2021. Published by Elsevier B.V.)

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., Competing Interests: Declaration of competing interest The authors have no conflict of interest with this work., (Copyright © 2021. Published by Elsevier B.V.)

Background: The valorization of organic wastes through fast pyrolysis appears to be a highly promising option for decreasing pollutants and reducing consumption of natural resources. For this purpose, three different olive pomace samples were studied to determine how olive crop location and the extraction process could influence bio-oil product distribution. Olive pomace was selected as the feedstock due to the importance of the olive oil industry in Spain., Results: In this study, the conditions of fast pyrolysis were optimized using lignin as a reference, with the optimum conditions being 500 °C, 20 °C ms -1 as the heating rate and 15 s as the vapour residence time. The olive pomace results determined that not only their chemical composition, but also their fat content had a remarkable effect on product distribution obtained after fast pyrolysis. However, whereas high lignin content enhanced phenol production, cellulose decomposed to carboxylic acids. In addition, due to current global warming, the carbon dioxide (CO 2 ) burden of the three samples was calculated using mass spectroscopy. The OPGC sample gave off the lowest amount of greenhouse gases, followed by OPMNE and OPMN., Conclusions: The higher fat content in the sample enhanced carboxylic acid production. The difference in phenol production between OPMN and OPMNE could be attributed to the presence of potassium. From an environmental point of view, the use of olive pomace wastes could reduce CO 2 emissions with further research and by developing experimental processes. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

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., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Orange bagasse (OB) is an agroindustrial residue of great economic importance that has been little explored for the extraction of cellulose. The present study aimed to investigate different combinations of chemical (sodium hydroxide, peracetic acid and alkaline peroxide) and physical (autoclaving and ultrasonication) treatments performed in one-step processes for cellulose extraction from OB and to characterize the materials obtained according to their composition, morphology, crystallinity and thermal stability., Results: The processing yields ranged from 140 to 820 g kg -1 , with a recovery of 720-1000 g kg -1 of the original cellulose. Treatments promoted morphological changes in the fiber structure, resulting in materials with higher porosity, indicating partial removal of the noncellulosic fractions. The use of combined chemical treatments (NaOH and peracetic acid) with autoclaving was more efficient for obtaining samples with the highest cellulose contents., Conclusion: Therefore, AC SH (processed by autoclaving with NaOH) was the most effective one-step treatment, resulting in 71.1% cellulose, 0% hemicellulose and 19.0% lignin, with a crystallinity index of 42%. The one-step treatments were able to obtain materials with higher cellulose contents and yields, reducing reaction times and the quantity of chemical reagents employed in the overall processes compared to multistep conventional processes. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

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 β-O-4 and C 5 -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., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2021. Published by Elsevier B.V.)

This study aims to investigate the relationship between lignin content, morphology, and rheology of lignin containing cellulose nanofibers (LCNFs). The morphology and rheology of LCNFs were dominated by lignin content. Lignin content had two-sides on mechanical fibrillation. At high lignin content (23.79 %), reduced efficiency of defibrillation resulted in large LCNFs connecting with lignin patches. LCNF suspensions exhibited low viscosity, weak gel behavior due to infirm fibril network. Small yield stress of 1.14 Pa suggested that fibril network was easily disrupted. At residual lignin of 6.52 %, fibril bundles were sensitive to defibrillation, producing long and flexible LCNFs with high capacity of entanglement. The entangled fibril network had high viscosity and strong gel like behavior. Creep compliance of 0.09 Pa -1 and large yield stress of 4.25 Pa indicated excellent resistance to deformation. The desired rheology can be tailored by lignin content, providing practical guidance on novel rheology-dependent LCNF based materials., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A lignin sample was extracted from Eucalyptus grandis sawdust, by the Klason method, and used as adsorbent for the removal of methylene blue (MB) from aqueous solutions. By using a set of complementary analytical tools, the lignin appeared to be constituted of oxygenated functional groups and aromatic moieties, while showing a specific surface area of 20 m 2  g -1 and polydisperse particles. Different experimental conditions with various solid to liquid ratio, pH, as well as other external experimental parameters were investigated for the removal of MB by the lignin sample. The experimental adsorption data at the equilibrium were properly fitted by Langmuir model, while adsorption kinetical isotherms were correctly adjusted by the pseudo-second order model. The MB removal by lignin was spontaneous involving physisorption mechanisms leading to a saturation of the adsorption sites with a maximum adsorbed amount of about 32 mg g -1 . The data acquired in this study also emphasized the interests to use lignin as potential adsorbent in the light of its properties for the removal of cationic dyes, including MB, with possible recycling and reuse cycles of lignin without any significant loss of its properties., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Better understanding through direct observation of the mechanisms involved in chemical and enzymatic hydrolysis of biomass is of great importance, to implement a substitute for the common cellulose standards. We report the hydrolysis of biomass, using exclusively the parenchyma, to isolate cellulose nanoplatelets using a less harsh pretreatment. Then, we show direct evidence of the effect of endoglucanase on the structure of cellulose nanoplatelets, finding that amorphous cellulose is exclusively digested, loosening the cellulose nanofibrils in the process. The analysis of micrographs demonstrates that when cellulose nanoplatelets are deposited on a silicon wafer, its thickness can be qualitatively measured by the interference color detected using an optical microscope. This finding facilitates further studies of mechanisms involved in lignin removal and cellulose nanofibrils production by specific enzymatic digestion., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

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.

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), 31 P 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., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Lignin was extracted from oil palm empty fruit bunches under four different conditions. The lignin samples were characterized and employed in the green synthesis of silver nanoparticles. Two-dimensional HSQC NMR analysis showed that lignins extracted under more aggressive conditions (3.5% acid, 60 min) exhibited less signals and thus, presented a more degraded chemical structure. Additionally, those lignins obtained under harsh conditions (3.5% acid, 60 min) exhibited higher antioxidant capacity than those obtained under mild conditions (1.5% acid, 20 min). Formation of lignin-mediated silver nanoparticles was confirmed by color change during their synthesis. The surface plasmon resonance peaks (423-427 nm) in UV-visible spectra also confirmed the synthesis of AgNPs. AgNPs showed spherical shape, polycrystalline nature and average size between 18 and 20 nm. AgNPs, in suspension, presented a negative Zeta potential profile. Lignin was assumed to contribute in the antioxidant capacity exhibited by AgNPs. All AgNPs presented no significant differences on the disk diffusion antimicrobial susceptibility test against E. coli. The minimum inhibitory concentration of HAL3-L AgNPs (62.5 μg·mL -1 ) was better than other physicochemically produced AgNPs (100 μg·mL -1 )., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Lignin valorisation into materials such as resins is essential to increase the value obtained from biomass. However, biomass recalcitrance limits the selective isolation of lignin for economic gains. This study developed a new process for fractionating alkaline treated mango seed husk into high purity lignin and cellulose-rich pulp, using high shear homogenization-organosolv (HSHO) process. The HSHO process conditions (ethanol concentration (50-70%), temperature (130-150 °C) and homogenizing time (10-20 min)) were optimized using response surface methodology to maximize the solubilised lignin with high purity while obtaining a fibrillated cellulose-rich pulp. Optimum process conditions of 60% ethanol, 148.41 °C, and 15 min homogenization, yielded 70.23% lignin of 96.18% purity, higher than those of the non-assisted process (68.58% and 94.74%, respectively). Nuclear magnetic resonance spectroscopy showed syringyl and guaiacyl lignin units with a molecular weight of 3247 g/mol and thermal degradation temperature of 298 °C. Sulphur and nitrogen contents in the resulting lignin were lower than 0.15%. Fibrillated cellulose pulp with diameters of <1-10 μm were obtained. This study has established the proficiency of an HSHO process for biomass fractionation and more so, for the extraction of lignin with >90% purity suitable for varied applications., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Lignin, the term commonly used in literature, represents a group of heterogeneous aromatic compounds of plant origin. Protolignin or lignin in the cell wall is entirely different from the commercially available technical lignin due to changes during the delignification process. In this paper, we assess the status of lignin valorization in terms of commercial products. We start with existing knowledge of the lignin/protolignin structure in its native form and move to the technical lignin from various sources. Special attention is given to the patents and lignin-based commercial products. We observed that the technical lignin-based commercial products utilize coarse properties of the technical lignin in marketed formulations. Additionally, the general principles of polymers chemistry and self-assembly are difficult to apply in lignin-based nanotechnology, and lignin-centric investigations must be carried out. The alternate upcoming approach is to develop lignin-centric or lignin first bio-refineries for high-value applications; however, that brings its own technological challenges. The assessment of the gap between lab-scale applications and lignin-based commercial products delineates the challenges lignin nanoparticles-based technologies must meet to be a commercially viable alternative.

In this work, twenty-five kinds of choline chloride (ChCl)-based deep eutectic solvents (DESs) containing acid, hydroxyl, amide, and binary hydrogen bond donors (HBDs) were prepared and successfully used to pretreat pine wood powder. As a result of the pretreatment, the glucan content in the pretreated biomass was increased, whereas the contents of hemicellulose and lignin were significantly decreased. The biomass pretreatment efficiency of the DESs had improved with increasing the polarity and hydrogen bond acidity (α) of the DESs. Among the studied DESs, ChCl:lactic acid:formic acid (1:1:1) with the highest α value was the most efficient DES in extracting lignin from biomass. The pretreated biomass also showed an enhanced enzymatic saccharification yield owing to the decreased particle size of the biomass and reduced content of hemicellulose and lignin. During the pretreatment process of biomass using DESs, the extracted lignin could be recovered successfully, with a yield of up to 60% and purity of over 90%. The molecular weight of the extracted lignin was much lower than that of the native cellulolytic enzyme lignin. The DES used for pretreatment process could be also successfully reused with high recovery yield of DES and high retention of delignification capacity., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In this work, deep eutectic solvent (DES) was prepared by mixing choline chloride (ChCl) with lactic acid (LA), and effects of cellulase non-productive binding onto DES-extracted lignin from willow and corn stover on enzymatic hydrolysis of cellulose was investigated. The correlation between hydrolysis yield of cellulose and chemical features of lignin was evaluated, and a potential inhibitory mechanism was proposed. Condensation of lignin was observed during DES treatment, and these condensed aromatic structures had an increased tendency to adsorb enzymes through hydrophobic interactions. As well as hydrophobic interactions mediated by lignin condensation, an increase in phenolic hydroxyl groups resulted in a greater amount of hydrogen bonds between cellulases and lignin that appeared to inhibit enzymatic hydrolysis yields of cellulose (39.96-42.86 % to 31.96-32.68 %). Although large amounts of COOHs were generated, the elevated electrostatic repulsion as a result of ionic groups was insufficient to decrease non-productive adsorption., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A high-throughput agarose gel electrophoresis (AGE) analytical method has been developed to separate lignin fractions according to their molecular weight ( M w ), charge, and shape. Operating conditions to effect separation of species have been evaluated along with imaging parameters. Kraft, soda (Protobind), and Organosolv lignins showed distinct differences in migration. Bands were cut, extracted, and cross-analyzed by gel permeation chromatography (GPC), 1 H NMR, and pyrolysis GC/MS to confirm their identity as lignin. The band intensity was correlated with lignin concentration by running serially diluted samples and imaging each lane to produce a precise calibration curve. The AGE technique was used to monitor and compare enzymatic, bacterial, chemical, and hydrothermal lignin digestions. Each method showed changes in lignin migration and band intensities over time. Low M w species were seen in samples collected from the anode buffer tank. Though requiring further development, the AGE method can provide structural information about the lignin and is accessible to biological and chemistry laboratories.

Lignins of non-woody fast-growing plants cause high interest in recent time as a potential source of raw materials for biorefining. Studying of the lignin structure in shrubs will allow obtaining the information about processes of biosynthesis of these plants and developing methods of their delignification for bioprocessing industry. We studied the structure of raspberry dioxane lignin (Rubus idaeus L.) using various spectroscopic methods, including FT-IR and NMR (1D and 2D) for various nuclei. Also, we used gel permeation chromatography and elemental analysis. It is obtained that raspberry dioxane lignin has relatively wide polydispersity, with Mw/Mn = 2.6, and a relatively lower molecular weight (Mw = 5111 g/mol) due to low molecular weight oligolignols. 31 P-NMR spectroscopy allowed to obtain that raspberry lignin belongs to GS-type. Due to 13 C-NMR we calculated hypothetical empirical formula of the studied lignin and determined the substructures and ether bonds content. S/G ratio of lignin is important parameter for delignification process, and it is equal to 1.19 indicating that lignin rich in S-units will easily degrade even under mild alkaline conditions., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Understanding the structure and properties of lignin has important practical significance for its further applications. In this case, eucalyptus was fractionated with 88% formic acid at 101 °C for different durations, and the removal efficiency as well as the chemical structure of lignin at various stages were comparatively analyzed. The obtained data indicated that with increasing reaction time, lignin was continuously removed and the process could be divided into three stages. The lignin dissolution rate was fast first and then slow, and the molecular weight of the dissolved lignin increased with time. The lignin structure was condensed and the molecular weight increased with prolonged of reaction time. Structural analysis indicated that the β-O-4' structure was largely destroyed, the G-type lignin dissolved early, and the degradation of the S-type lignin became more intensive with increasing reaction time. This is of great help for reaction control as well as the further processing of lignin byproducts., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objectives: This study was designed to profile the chemical information of Forsythiae Fructus (FF) and investigate the in-vivo FF-related xenobiotics, especially for lignans., Methods: Rats were oral administrated of FF and pinoresinol-4-O-glucoside, respectively. Blood and urine samples were collected after ingestion, and xenobiotics was profiled by an UPLC/Qtof MS method., Key Findings: A total of 19 lignans were identified or tentatively characterized in FF, and 63 lignan-related xenobiotics were found in rat plasma and urine after ingestion of FF. It was found that lignans could be transformed into metabolites by furan ring opening, hydrogenation, demethylation, dehydration and phase II reactions (sulfation and glucuronidation). The whole metabolic behaviour of bisepoxylignan was revealed by evaluating the metabolism of pinoresinol-4-O-glucoside in vivo. It was found that the configuration of C-8/C-8' was retained after furan ring opening and metabolic reactions always occurred at position of C-3/C-4/C-5 or C-3'/C-4'/C-5'. Additionally, other types components in FF and in vivo were also characterized., Conclusions: This work revealed the in-vivo metabolism of FF, and reported the characteristic metabolic reactions of lignans for the first time. It was also provided the foundation for the further investigation on pharmacodynamic components of FF or TCMs containing FF., (© 2020 Royal Pharmaceutical Society.)

The removal of lignin is important to the recovery of saccharides from the pre-hydrolysis liquor (PHL) in kraft-based dissolved pulp production. A one-step process for lignin removal from PHL via treatment with horseradish peroxidase (HRP) in the presence of Ca 2+ was proposed, and its principle was studied. The results demonstrated synergy between HRP and Ca 2+ in lignin removal from PHL, whereas NH 4 + had little effect on lignin removal. HRP treatment in the presence of 60 mmol/L of Ca 2+ resulted in a lignin removal of 64.8% accompanied by a saccharide loss of 14.2%. HRP catalyzed both the polymerization and depolymerization of the lignin in the PHL. The HRP-catalyzed lignin polymerization rendered some lignin insoluble enabling it to be directly removed. The HRP-catalyzed depolymerization of lignin decreased its molecular weight with an evident increase in its carboxyl content. The insoluble complexes formed between the lignin with carboxyl and the Ca 2+ facilitated the removal of the depolymerized lignin., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Ginkgo shells as by-products from Ginkgo biloba L. industries with a remarkable annual output up to now are not fully analyzed and exploited. For the application of ginkgo shells beyond their current roles, structure and antioxidant activity of milled wood lignins successively extracted from two ginkgo shell species were investigated. Results showed lignin in ginkgo shells is abundant in guaiacyl units with the presence of ferulates and p-coumarates and demonstrates a high yield of vanillin (1.47-1.65 mmol/g-lignin) by nitrobenzene oxidation, much higher than general softwoods and hardwoods (0.6-0.9 mmol/g-lignin), which makes ginkgo shells good feedstocks for the production of food and beverage flavoring agent. By increasing the extent of ball-milling (4-8 h), the polydispersity of lignin molecular weight exhibits negligible change, but condensation and aldol interconversion occur to its C β /C 5 structure and end-groups, respectively. Lignin in ginkgo shells also features outstanding antioxidant activity with the optimal radical scavenging index of 6.9, much higher than commercial butyl hydroxyanisole (3.85) and butylated hydroxytoluene (0.29), and the phenolic hydroxyl is demonstrated to dominate this contribution by the analysis of statistical product and service solutions. These results reveal lignin in ginkgo shells shows many unique structural and biological properties for materials., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2020. Published by Elsevier B.V.)

Nanocellulose is a promising material but its isolation generally requires unrecyclable hazardous chemicals and high energy consumption and its overall yield is low due to the use of high purity cellulose as precursor. In order to overcome these shortcomings, in this study, thermomechanical pulp (TMP) was investigated as a precursor for isolating lignin containing nanocellulose (LNC) using an environmentally friendly acidic deep eutectic solvent (DES) pre-treatment. Flat "ribbon" like LNCs (around 7.1 nm wide, 3.7 nm thick) with uniformly distributed lignin nanoparticles of 20-50 nm in diameter were successfully obtained at 57 % yield under optimum pre-treatment conditions (90 °C, 6 h, 1:1 oxalic acid dihydrate to choline chloride ratio). The LNCs exhibit cellulose Iβ structure, high lignin content (32.6 %), and high thermal stability (T max of 358 °C). In general, green acidic DES pre-treatment has shown high efficiency in converting high lignin content biomass into value-added LNC, which benefits both lignocellulose utilization and environmental protection., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The most critical issues faced by the world nowadays is to provide the sustainability of consumption for energy and natural resources. Lignin is said to be one of the alternative new discoveries best-suited lignocellulosic biomass due to its low cost, sufficient availability and environmentally safe. The valuable properties exhibited by lignin can give broader applications usage such as in composite materials, wood industries, polymer composite industries, pharmaceutical and corrosion inhibitor industries. Many biomass wastes resources, isolation processes and treatments are undergoing development in order to enhance the producing new lignin-based materials on an industrial scale. Therefore, this review discussed on the current knowledge on the structure and chemistry of isolation of lignin from different sources using various common methods, its characterization, properties and its applications., (Copyright © 2020. Published by Elsevier B.V.)

Ultrasound-assisted-alkali-urea (UAAU) pre-treatment of miscanthus biomass was investigated for enhanced delignification and extraction of cellulose fiber. The effects of pre-treatment conditions investigated were: sonication time (10.0, 15.0 and 20.0 min), alkali (NaOH) concentration (2.0, 3.5 and 5.0 %, w/v) and urea-concentration (1.0, 1.75 and 2.5 %, w/v) on the delignification and cellulose content. The process parameters were studied and optimized using a response surface methodology (RSM) based on the Box Behnken Design (BBD). From the RSM-BBD analysis, he optimized pre-treatment conditions were 2.1 % NaOH, 1.7 % urea and 15.5-min sonication time with maximal cellulose and lignin contents of 47.8 % (w/w) and 27.5 % (w/w) respectively. The pre-treated samples were further characterized by FTIR, colorimeter, SEM, XRD, and TGA analyses. The UAAU pre-treated samples have higher delignification and cellulose contents than the AU pre-treatment without sonication. Furthermore, the ultrasound process allowed selective removal of lignin without substantially degrading the functionalities of cellulose fiber. The UAAU pre-treated samples exhibited higher thermal stability, fibrillation, crystallinity index and smaller crystallite size., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

While the cashew culture is focused on processing and commercialization of cashew nuts, the pseudofruit (cashew apples) - highly perishable and of limited acceptance - are mostly wasted. The cashew tree pruning fiber (CTPF) is another interesting cashew byproduct. In this study, films have been made from bacterial cellulose produced from cashew apple juice, and added with lignin (0-15 wt%) and cellulose nanocrystals (0-8 wt%), both from CTPF, which enhanced tensile properties and decreased water vapor permeability of the films. Moreover, lignin, although imparting brown color and opacity to the films, was effective to provide the films with UV-absorbing and antioxidant properties, making the films interesting for packaging of food products susceptible to lipid oxidation. The films did not exhibit antimicrobial activity against bacteria or yeasts., Competing Interests: Declaration of competing interest The authors have no conflicts of interest to declare., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A compounded medium of supercritical CO 2 , ethanol, and water (SEW) was used to extract lignin from eucalyptus fiber and the mechanism of the extraction was studied. Compared with the extraction method based on high-temperature ethanol (HTE), the lignin yield of the SEW method was 49.7% higher with higher average molecular weight. Physical and chemical synergies occurred during the extraction process. SEW compound medium penetrated eucalyptus fiber cell walls because of strong permeability, while the fast discharge of the compounded medium facilitated efficient lignin dissociation and removal. Carbonic acid formed from CO 2 and water under high temperature and pressure can provide an acidic environment to effectively degrade hemicellulose. Formaldehyde formed from CO 2 and ethanol in the process also prevented condensation of the extracted lignin fragments. The obtained lignin had high content of β-O-4 linkages and syringyl units., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Granulated cork was submitted to subcritical water extraction/hydrolysis in a semi-continuous reactor at temperatures in the range of 120-200 °C and with a constant pressure of 100 bar. The influence of temperature on the composition of the cork extracts obtained was assessed-namely, their content of carbohydrates and phenolics. The extraction yield increased with the temperature, and this was associated with the decrease in the dielectric constant of water and the increase in its ionic product. Extracts composed of up to 36% phenolics were obtained at temperatures of up to 120 °C, with an antioxidant activity only two times lower than that of pure gallic acid, but in low amounts. Assays at higher temperatures generated extracts richer in carbohydrates and with a phenolics content of ca. 20 wt.% in comparatively far higher amounts. Neither the amount of suberin nor its structure were affected by the subcritical water treatment.