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The formation of humins hampers the large-scale production of 5-hydroxymethylfurfural (HMF) in biorefinery. Here, a detailed reaction network of humin formation at the initial stage of fructose-to-HMF dehydration in water is delineated by combined experimental, spectroscopic, and theoretical studies. Three bimolecular reaction pathways to build up soluble humins are demonstrated. That is, the intermolecular etherification of β-furanose at room temperature initiates the C12 path, whereas the C–C cleavage of α-furanose at 130–150 °C leads to C11 path, and that of open-chain fructose at 180 °C to C11′ path. The successive intramolecular dehydrations and condensations of the as-formed bimolecular intermediates lead to three types of soluble humins. We show that the C12 path could be restrained by using HCl or AlCl3 catalyst, and both the C12 and C11′ paths could be effectively inhibited by adding THF as a co-solvent or accelerating heating rate via microwave heating.

The chemical transformation of natural oils provides alternatives to limited fossil fuels and produces compounds with added value for the chemical industries. The selective deoxygenation of natural oils to diesel-ranged hydrocarbons, bio-jet fuels, or fatty alcohols with controllable selectivity is especially attractive in natural oil feedstock biorefineries. This review presents recent progress in catalytic deoxygenation of natural oils or related model compounds (e.g., fatty acids) to renewable liquid fuels (green diesel and bio-jet fuels) and valuable fatty alcohols (unsaturated and saturated fatty alcohols). Besides, it discusses and compares the existing and potential strategies to control the product selectivity over heterogeneous catalysts. Most research conducted and reviewed has only addressed the production of one category; therefore, a new integrative vision exploring how to direct the process toward fuel and/or chemicals is urgently needed. Thus, work conducted to date addressing the development of new catalysts and studying the influence of the reaction parameters (e.g., temperature, time and hydrogen pressure) is summarized and critically discussed from a green and sustainable perspective using efficiency indicators (e.g., yields, selectivity, turnover frequencies and catalysts lifetime). Special attention has been given to the chemical transformations occurring to identify key descriptors to tune the selectivity toward target products by manipulating the reaction conditions and the structures of the catalysts. Finally, the challenges and future research goals to develop novel and holistic natural oil biorefineries are proposed. As a result, this critical review provides the readership with appropriate information to selectively control the transformation of natural oils into either biofuels and/or value-added chemicals. This new flexible vision can help pave the wave to suit the present and future market needs.

Ni-based catalysts using ε-, α- and β-MnO2 crystal phases supports were prepared and applied to CO2 hydrogenation. The samples were characterized by XRD, H2-TPR, BET, SEM, (HR)TEM, CO2-TPD, Raman, quasi in situ XPS, and in situ DRIFTS. Ni/MnOx-NS (ε-MnO2) was found to exhibit stable activity (with 69.0% CO2 conversion) and selectivity to CH4 (99.0%) at 350 ℃, much higher than Ni/MnOx-R (α-MnO2) and Ni/MnOx-B (β-MnO2). Partially reduced Mn3+ and enriched defects facilitated CO2 and intermediates adsorption/activation, enabling unpaired electrons trapped in defect oxide surface to accelerate the cleavage of C-O to form CH4 assisted by active H, whereas CO production via reverse water-gas reaction was strongly suppressed. This work highlights the key role of synergistic interaction between Ni and MnOx-NS and CO2 activation abilities by various MnO2, which directed the selective CO2 hydrogenation performance.

Pyrolysis of biomass converts all components into liquid, gaseous, and solid products without the need for component separation. However, the composition of liquid products from lignocellulosic biomass is usually complex and difficult to upgrade. Slow pyrolysis of de-oiled rapeseed cake, an agricultural waste from the rapeseed pressing process, was carried out for liquid and solid fuel production. The maximum yield of bio-oil obtained was 51.6 wt.% under the optimized conditions. The HHV of the bio-oil, containing mainly acids, hydrocarbons, esters, and alcohols, was 32.82 MJ·kg−1, similar to that of bio-diesel, to be promising in downstream upgrading because the fuel properties such as higher caloric value, limited moisture content, as well as neutral pH value, were close to commercial bio-diesel. The gaseous fraction mainly consisted of CO, C1, C2 hydrocarbons, H2, and CO2, and the corresponding LHV reached 7.63 MJ·Nm−3. The yield of bio-chars declined from 41.8 wt.% at 400 °C to 28.8 wt.% at 800 °C, whereas the corresponding HHV varied from 29.03 MJ·kg−1 to 30.14 MJ·kg−1, comparative to coal, indicating a promising candidate for solid fuels or functional carbon. The liquid product shows promise as feedstock for producing high-quality fuel.

The present study reports on the adsorptive removal of heavy metals (Cr3+, Cd2+, and Cu2+) from water by a series of Lycium barbarum branch-based adsorbents: Lycium barbarum branch (denoted as LB), fungal fermented LB (FLB), LB biochar (LBB), FLB biochar (FLBB), alkaline modified LBB (ALBB), and alkaline modified FLBB (AFLBB). The six adsorbents were characterized in terms of FTIR, SEM, surface area and pore size as well as zeta potential. The adsorptive potential of these adsorbents was tested under varying conditions – pH, contact time, initial concentration, and temperature. Adsorption results were well fitted with Langmuir, Freundlich, and Temkin models. The maximum adsorption capacity (qm) was calculated to be 6.29 mg/g for Cr3+ by FLB, 11.53 mg/g for Cd2+ by LB, and 7.27 mg/g for Cu2+ by LB. The pseudo-second-order kinetic equation better described the adsorption process. Based on the thermodynamics parameters, the adsorption of heavy metals was endothermic but not spontaneous for biochars. The experimental results offer a new way for recycling and reutilizing LB in wastewater treatment. HIGHLIGHTS Lycium barbarum branch (LB) was used to adsorb Cu2+, Cr3+, and Cd2+.; LB was further modified with fungal fermentation and O2-free pyrolysis.; Isotherm, kinetic, and thermodynamic of adsorption were fitted and analyzed.; Modified LB-based adsorbents showed varied adsorption capacity and behavior.; LB and FLB are novel and promising adsorbents.;

In this work, we synthesized folate-conjugated dual-drug loaded double liposomes which are noted for their extremely high target specificity towards pituitary adenomas. It is known that while folate receptors are almost non-existent in normal tissues, they are overexpressed in non-functional pituitary adenomas. Synthesis, characterization and in vitro studies of folate-conjugated dual-drug loaded double liposomes for targeting non-functional pituitary adenomas is the highlight of this study. The size, zeta-potential, polydispersity index, in vitro release studies, stability of the nanoformulation, cytotoxicity and cellular uptake studies have been carried out. It was noted from the results that these are highly targeted liposomal formulation as expressed by the cellular uptake studies and are just sufficiently sized to escape the clearance mechanisms of body. They were also cytocompatible and were stable even after 60 days of shelf life with negligible changes in sizes, zeta potential as well as polydispersity index. The conjugation with folate particles resulted in the high specificity of the formulation to the specific targeted tissue as seen in cellular uptake by primary cell culture of non-functional pituitary adenomas. It may safely be concluded from the results that this approach may be a promising therapy for the future which has low cytotoxicity and high-specificity.

Abstract Soil microbe is crucial to a healthy soil, therefore its diversities and abundances under different conditions are still need fully understand.The aims of the study were to characterize the community structure and diversity of microbe in the rhizosphere soil after continuous maize seed production, and the relationship between the disease incidence of four diseases and the variation of the rhizosphere microbe. The results showed that different fungal and bacterial species were predominant in different cropping year, and long-term maize seed production had a huge impact on structure and diversity of soil microbial. Ascomycota and Mortierellomycota were the dominant fungal phyla and Mortierella and Ascomycetes represented for a large proportion of genus. A relative increase of Fusarium and Gibberella and a relative decrease of Mortierella, Chrysosporium, Podospora, and Chaetomium were observed with the increase of cropping year. Pathogenic Fusarium, Curvularia, Curvularia-lunata, Cladosporium, Gibberella-baccata, and Plectosphaerellaceae were over-presented and varied at different continuous cropping year, led to different maize disease incidence. Proteobacteria and Actinobacteria ranked in the top two of all bacterial phyla, and genus Pseudarthrobacter, Roseiflexus and RB41 dominated top 3. Haliangium and Streptomyces decreased with the continuous cropping year and mono-cropping of maize seed production increased disease incidence with the increase of cropping year, while the major disease was different. Continuous cropping of maize seed production induced the decrease of protective microbe and biocontrol genera, while pathogenic pathogen increased, and maize are in danger of pathogen invasion. Field management show great effects on soil microbial community.

Hepatitis B virus (HBV) infection is the main risk factor for the development of hepatocellular carcinoma (HCC), the most common type of liver cancer, with high incidence and mortality worldwide. Surgery, liver transplantation, and ablation therapies have been used to treat early HBV-caused HCC (HBV-HCC); meanwhile, in the advanced stage, chemoradiotherapy and drug-targeted therapy are regularly considered, but with limited efficacy. Recently, immunotherapies, such as tumor vaccine therapy, adoptive cell transfer therapy, and immune checkpoint inhibitor therapy, have demonstrated promising efficacy in cancer treatment. In particular, immune checkpoint inhibitors can successfully prevent tumors from achieving immune escape and promote an anti-tumor response, thereby boosting the therapeutic effect in HBV-HCC. However, the advantages of immune checkpoint inhibitors in the treatment of HBV-HCC remain to be exploited. Here, we describe the basic characteristics and development of HBV-HCC and introduce current treatment strategies for HBV-HCC. Of note, we review the principles of immune checkpoint molecules, such as programmed cell death protein 1(PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) in HBV-HCC, as well as related inhibitors being considered in the clinic. We also discuss the benefits of immune checkpoint inhibitors in the treatment of HBV-HCC and the efficacy of those inhibitors in HCC with various etiologies, aiming to provide insights into the use of immune checkpoint inhibitors for the treatment of HBV-HCC.

The targeted application of lignin needs deeper understanding of its physicochemical property. Herein, three kinds of organosolv lignin samples were obtained from willow using three typical organosolv-water co-solvents, and their properties and pyrolysis behaviors were studied by various characterization methods. It was found that the used solvents exerted different effects on lignin samples: lignin extracted from ethyl acetate-water co-solvent possessed more functional groups containing oxygen, and lignin extracted from γ-butyrolactone-water co-solvent contained more large-molecule fragments; the degradation temperature with the maximum rate in thermogravimetric analysis were 352, 384, and 398 ℃ for lignin samples extracted by ethyl acetate/tetrahydrofuran/γ-butyrolactone-water co-solvent, respectively. The cleavage of Cα-Cβ linkage performed more acutely in pyrolysis of lignin extracted from γ-butyrolactone-water co-solvent, while the linkage of C1-Cα in lignin extracted by ethyl acetate/tetrahydrofuran-water co-solvent was more fragile. With regard to the mono-phenolic products, the pyrolysis of lignin extracted from ethyl acetate-water co-solvent yielded guaiacol and 4-methylguaiacol dominantly, and lignin extracted by tetrahydrofuran-water co-solvent produced more guaiacol, 4-ethylguaiacol, and 4-methylguaiacol while lignin extracted by γ-butyrolactone-water co-solvent yielded the maximum amount of 4-methylguaiacol. In addition, the pyrolysis of lignin samples extracted by γ-butyrolactone-water co-solvent yielded only H2, CH4 and CO as gaseous products while the other two yielded H2, CH4, CO and CO2.

A multifunctional Ru/SBA‐15 catalyst is prepared via impregnation and used in the depolymerization of crude waste corn stover enzymatic lignin (CSEL) to produce monophenols and, unexpectedly, the industrially important organic siloxanes. In the depolymerization of CSEL over Ru/SBA‐15, a high phenolic monomer yield of 13.91 wt% with a high selectivity to ethylphenols (≈61%) can be achieved. Unexpectedly, when the reaction is carried out in ethanol, the predictable phenolic products are accompanied by both diethyl dimethyl orthosilicate and tetraethyl orthosilicate with the methyl group likely to come from lignin methoxy groups. Changing to a different alcohol solvent changes the siloxane products accordingly. The characterization of catalysts indicates that Ru0 is the active species in Ru/SBA‐15 catalysts and is well dispersed with small particle size (6.2 nm). This catalyst significantly contributes to both the production of phenols and siloxanes and contributes to the hydrogenolysis/hydrogenation of lignin.

Valuable furfuryl alcohol (FFA) and 2,5-dihydroxymethylfuran (DHMF) could be produced by selective hydrogenation of biomass-derived furfural (FF) and 5-hydroxymethylfurfural (HMF) with high atom economy. In this study, SBA-15 (a kind of mesoporous silica molecular sieve)-supported low metal loading (3 wt% total metal content) PtNi alloy catalyst (PtNi/SBA-15) was synthesized via two steps, including the generation of PtNi alloy by hydrothermal method, and the immobilization of PtNi alloy on SBA-15. PtNi/SBA-15 has ordered mesoporous structure with high surface area, and high dispersion of the PtNi alloy with the formation of Ptδ−-Niδ+ surface pairs on SBA-15, which benefit hydrogen activation and selective carbonyl hydrogenation. The selective hydrogenation of FF and HMF over PtNi/SBA-15 in water solvent at 303 K with 1.5 MPa H2 within 2 h, could respectively yield 64.6% FFA with 77.0% selectivity, and 68.2% DHMF with 81.9% selectivity. Besides, PtNi/SBA-15 exhibited a satisfactory water resistance and stability after recycling at least five runs.

Summary: D-lactic acid (D-LaA) synthesis directly from actual biomass via chemocatalytic conversion has shown high potential for satisfying its enormous demand in widespread applications. Here we report yttrium (Y(III))-species-catalyzed conversion of xylose and raw lignocelluloses to LaA with the highest yield of 87.3% (20% ee to D-LaA, ee%=(moles of D-LaA - moles of L-LaA)/(moles of D-LaA + moles of L-LaA) × 100). Combining experiments with theoretical modeling, we reveal that [Y(OH)2(H2O)2]+ is the possible catalytically active species, enabling the unconventional cleavage of C3-C4 in xylulose and the subsequent dehydration of glyceraldehyde to pyruvaldehyde (PRA). The distinct interactions between hydrated-PRA and [Y(OH)2(H2O)2]+ species contribute to the formation of different enantiomers, wherein H-migration via re-face attack leads to L-LaA and that via si-face attack yields D-LaA. The lower strain energy barrier is the origin of excess D-enantiomer formation. : Chemistry; Catalysis; Biomaterials Subject Areas: Chemistry, Catalysis, Biomaterials

Degradation solutions containing atrazine need to be further purified before they are discharged into the aquatic environment. With the objectives of evaluating removal capacity of the microalga Chlorella sp. toward atrazine in degradation solutions and toxicity of the degradation products, we investigated the removal efficiency (RE) and bioaccumulation of atrazine in the microalgae after an 8 d exposure to diluted degraded solutions containing 40 μg/L and 80 μg/L of atrazine as well as degradation products in the present study. Moreover, pure atrazine solutions with similar concentrations were simultaneously inoculated with the microalgae in order to distinguish the influence of the products. The photocatalytic degradation results showed that 31.4% of atrazine was degraded after 60 min, and three degradation products, desisopropyl-atrazine (DIA), desethyl-atrazine (DEA), and desethyl-desisopropyl-atrazine (DEIA) were detected. After an 8-d exposure, 83.0% and 64.3% of atrazine were removed from the degraded solutions containing 40 μg/L and 80 μg/L of atrazine, respectively. In comparison with the control, i.e., pure atrazine solution with equal concentration, Chlorella sp. in the degraded atrazine solution showed lower RE and growth rate. The photosynthetic parameters, especially performance index (PIABS), clearly displayed the differences between treatments. The values of PIABS of Chlorella sp. cultured in degradation atrazine for 8 days were significantly lower (P

Lignocellulosic biomass as a potential alternative to fossil resource for the production of valuable chemicals and fuels has attracted substantial attention, while reducing the recalcitrance of lignocellulosic biomass is still challenging due to the complex and cross-linking structure of biomass. Solvent system plays important roles in the pretreatment of lignocellulose, enabling the transformation of solid biomass to liquid fluid with better mass and heat transfer, as well as in the selective formation of target products. In particular, H2O/tetrahydrofuran (H2O/THF) system has recently been widely applied in lignocellulose valorization, which has been proved to exhibit outstanding efficiency for the conversion of lignocellulose, solubilization of the intermediates and products, and shifting reaction equilibrium, thereby significantly improving the yield and selectivity of target products, as well as the full utilization of lignocellulose. In addition, THF shows low toxicity, and is known as a renewable solvent which can be produced from bio-derived chemicals. Herein, this review concentrates on the advances of H2O/THF system in lignocellulose valorization in recent years. Several aspects relative to the roles of H2O/THF system are discussed as follows: the pretreatment of lignin, conversion of hemicellulose and cellulose components in lignocelluloses, and the promoting formation of valuable chemicals like furfural, 5-hydroxymethyl furfural (HMF), levulinic acid, and so on, as well as the inhibiting role in humins formation. This review might provide useful information for the design of effective solvent system in full utilization of lignocellulosic biomass.

As the first practical representative technology in the new quantum revolution,quantum key distribution (QKD) brings a promising solution to achieve long-term security guarantee,which has made series of progress from research to practical deployment and applications in recent years.The architecture design of quantum secure communication network was firstly discussed,which extended point-to-point QKD link to multi-user QKD network.Furthermore,combining with the classical cryptography,an enhanced solution was proposed to apply the quantum key generated by QKD to the mobile terminals,which offered the possibility to apply QKD in general mobile applications.

Natural microalgae (NA, cyanobacteria) collected from Taihu Lake (Jiangsu, China) were used for biofuel production through pyrolysis. The microalgae were de-ashed via pretreatment with deionized water and hydrochloric acid, and the samples obtained were noted as 0 M, 0.1 M, 1 M, 2 M, 4 M, 6 M, 8 M, respectively, according to the concentration of hydrochloric acid used in the pretreatment. Pyrolysis experiments were carried out at 500 °C for 2 h. The products were examined by various techniques to identify the influence of the ash on the pyrolysis behavior. The results showed that the ash inhibited the thermal transformation of microalgae. The 2 mol/L hydrochloric acid performed the best in removing ash and the liquid yield increased from 34.4% (NA) to 40.5% (2 M). Metal-oxides (mainly CaO, MgO, Al2O3) in ash promoted the reaction of hexadecanoic acid and NH3 to produce more hexadecanamide, which was further dehydrated to hexadecanenitrile. After acid pretreatment, significant improvement in the selectivity of hexadecanoic acid was observed, ranging from 22.4% (NA) to 58.8% (4 M). The hydrocarbon compounds in the liquid product increased from 12.90% (NA) to 26.67% (2 M). Furthermore, the acid pretreatment enhanced the content of C9–C16 compounds and the HHV values of bio-oil. For natural microalgae, the de-ashing pretreatment before pyrolysis was essential for improving the biocrude yield and quality, as well as the biomass conversion efficiency.

Density functional theory (DFT) calculations were performed to investigate the mechanism and the enantioselectivity of the aza-Henry reaction of isatin-derived ketimine catalyzed by chiral guanidine–amide catalysts at the M06-2X-D3/6-311+G(d,p)//M06-2X-D3/6-31G(d,p) (toluene, SMD) theoretical level. The catalytic reaction occurred via a three-step mechanism: (i) the deprotonation of nitromethane by a chiral guanidine–amide catalyst; (ii) formation of C–C bonds; (iii) H-transfer from guanidine to ketimine, accompanied with the regeneration of the catalyst. A dual activation model was proposed, in which the protonated guanidine activated the nitronate, and the amide moiety simultaneously interacted with the ketimine substrate by intermolecular hydrogen bonding. The repulsion of CPh3 group in guanidine as well as N-Boc group in ketimine raised the Pauli repulsion energy (∆EPauli) and the strain energy (∆Estrain) of reacting species in the unfavorable si-face pathway, contributing to a high level of stereoselectivity. A new catalyst with cyclopropenimine and 1,2-diphenylethylcarbamoyl as well as sulfonamide substituent was designed. The strong basicity of cyclopropenimine moiety accelerated the activation of CH3NO2 by decreasing the energy barrier in the deprotonation step. The repulsion between the N-Boc group in ketimine and cyclohexyl group as well as chiral backbone in the new catalyst raised the energy barrier in C–C bond formation along the si-face attack pathway, leading to the formation of R-configuration product. A possible synthetic route for the new catalyst is also suggested.

Little is known about the molecular pathway to monomers of semiconductor nanocrystals. Here, the authors report a general reaction pathway based on hydrogen-mediated ligand loss for the precursor conversion to ‘monomers’ at low temperature prior to nucleation, via 31P NMR spectroscopic measurements.

As a standard testing organism in soil ecosystems, the earthworm Eisenia fetida has been used widely in toxicity studies. However, tests at the individual level are time- and animal-consuming, with limited sensitivity. Earthworm coelomocytes are important for the assimilation and elimination of exogenous compounds and play a key role in the processes of phagocytosis and inflammation. In this study, we explored an optimal condition to culture coelomocytes of E. fetida in vitro and investigated the cytotoxicity of multiwalled carbon nanotubes (MWCNTs) and sodium pentachlorophenol (PCP-Na) using coelomocytes via evaluating lethal toxicity, oxidative stress, membrane damage, and DNA damage. The results showed that coelomocytes can be successfully cultured in vitro in primary under the RPMI-1640 medium with 2-4×104 cells/well (1-2×105 cells/mL) in 96-well plates at 25°C without CO2. Both MWCNTs and PCP-Na could cause oxidative damage and produce ROS, an evidence for lipid peroxidation with MDA generation and SOD and CAT activity inhibition at high stress. The two chemicals could separately damage the cell membrane structure, increasing permeability and inhibiting mitochondrial membrane potential (MMP). In addition, our results indicate that PCP-Na may be adsorbed onto MWCNTs and its toxicity on earthworm was accordingly alleviated, while a synergetic effect was revealed when PCP-Na and MWCNTs were added separately. In summary, coelomocyte toxicity in in vitro analysis is a sensitive method for detecting the adverse effects of carbon nanotubes combined with various pollutants.

Density functional theory (DFT) calculations at the TPSSh-D3(BJ)/def2-TZVP (SMD, water) level of theory were performed to understand the mechanism of redox-neutral depolymerization of four types of lignin-derived aryl ether dimers catalyzed by rhodium-terpyridine ([Rh]) and a binuclear Rh complex ([2Rh]). The cleavage of the Cβ–O bond in the β-O-4 model compound was initiated by the dehydrogenation of the alcohol moiety into a ketone intermediate, followed by the reductive cleavage of the ether bond, producing phenol and aromatic ketone products. The [Rh]–OH intermediate, generated by the interaction between the Rh-complex and NaOH, facilitated the transformation of the alcohol group to a C=O group in the lignin model compound and subsequent H-transfer, selectively forming rhodium-H active species and the ketone intermediate. The [2Rh]–H complex exhibited high reactivity, with energy barriers for a rate-determining Cβ–O bond breakage of 35.3 kcal mol−1. In contrast to 1-phenylethan-1-ol and H2, lignin itself acted as a good hydrogen source to generate [Rh]–H species. The transformation of β-O-4 model compounds with the γ-OH group occurred via the elimination of the γ-OH group, reduction of the C=C bond, and Cβ–O bond cleavage steps. However, since lignin itself was unable to supply enough hydrogen to form [Rh]–H species, the aromatic products were obtained in low yields, as observed in the experiment. [ABSTRACT FROM AUTHOR]

Understanding the evolution, structure, and separation of humins (i.e., carbonaceous polymeric side-products) during the acid-catalyzed conversion of fructose, especially at high substrate loading, is of crucial importance for the future inhibition or application of humins. Herein, we report the sequential extraction and separation of soluble humins formed in the acid-catalyzed conversion of high-concentration fructose (20 wt%) to 5-ethoxymethylfurfural (EMF) and 5-hydroxymethylfurfural (HMF) in a mixed solvent of ethanol and 1,4-dioxane under microwave heating to understand the structural characteristics and evolution pathways of humins. We demonstrate the formation of four types of soluble humins during fructose-to-EMF/HMF conversion, wherein three of them were primarily composed of furan rings imported by self-etherification/hemiacetalation of HMF and subsequent aldol-condensation with ethyl levulinate (named humins I); cross-etherifi- cation between HMF, fructose, and ethanol (named humins III); and self-etherification/hemiacetalation of HMF and subsequent hemiacetalation with ethanol (named humins IV). In comparison, another type of humins (named humins II) was composed of fructose units introduced via self-etherification and subsequent dehydrations, wherein the as-formed difructose anhydride intermediates can be reversibly transformed back to fructose and finally into EMF and HMF by extending the reaction time, increasing the reaction temperature, or increasing the amount of the acid catalyst used. The above-mentioned structural diversity of humins accounted for their difference in polarity (II > III > IV > I) and allowed their sequential extraction and separation from the product mixture. This separation offers an opportunity to understand humin chemistry for the future sustainable production of value-added platform chemicals in biorefineries. [ABSTRACT FROM AUTHOR]