Ethanol: A Promising Green Solvent for the Deconstruction of Lignocellulose

A comprehensive review of sustainable valorisation of lignocellulosic biomass and plastic waste into biofuels and chemicals via co-liquefaction

Liquefaction stands out as a promising strategy within the bioeconomy, offering a pathway to convert waste into valuable fuels and products. However, bio-oil from biomass liquefaction has high oxygen content and poor calorific value, limiting its practical applications. To overcome these challenges, one promising approach is the co-liquefaction of oxygen-rich biomass with hydrogen-rich plastic, offering a sustainable means of producing high-quality oil. This review explores lignocellulosic biomass and plastic co-liquefaction, highlighting its behaviours, reaction pathways, and process parameters' effects. The co-liquefaction process offers significant advantages over lignocellulosic biomass or plastic liquefaction in improving oil quality and yield. Comprehensive studies on the effect of process parameters and reaction pathways are much needed to optimise the conditions and design an efficient and effective co-liquefaction process for lignocellulosic biomass and plastics. Life cycle assessment (LCA) and techno-economic assessment (TEA) are two viable approaches to evaluating the potential environmental impacts and economic performance, respectively. Finally, lignocellulosic biomass and plastic waste co-liquefaction is a viable approach to managing waste and producing valuable materials, which promotes significant values, including resource efficiency, waste reduction, environmental sustainability, and economic opportunities.

Investigation on the inactivation of Prorocentrum lima and degradation of diarrhetic shellfish toxins via peroxymonosulfate-based advanced oxidation process

Prorocentrum lima, a frequent harmful algal bloom species, secretes diarrhetic shellfish toxins (DSTs) that cause severe human gastrointestinal disorders. This study investigated a peroxymonosulfate (PMS)-based advanced oxidation process utilizing sulfate radicals for simultaneous algal inactivation and toxin degradation, addressing the current research gap in marine algal control. Microscopic analyses (optical/SEM) revealed structural disintegration and cytoplasmic leakage in treated cells. The observed 45.55-69.24 % reduction in chlorophyll a concentration critically impaired photosynthetic activity and DSTs biosynthesis. A 94.68 % decrease in viable cell ratio after 5 h PMS exposure confirmed effective algal eradication. Complementary mouse bioassays and LC-MS quantification demonstrated progressive toxin detoxification, evidenced by extended survival times and reduced DSTs concentrations. Membrane integrity analysis showed characteristic oxidative stress responses: malondialdehyde (MDA) levels surged during initial exposure (0-15 min), followed by superoxide dismutase (SOD) activity elevation (15-30 min) as cellular defense activation. The combined cell mortality and toxin attenuation confirm the dual efficacy of this approach. This cost-effective, operationally simple method presents a viable strategy for mitigating P. lima blooms and associated toxin hazards in marine environments.

Different manipulations for resolving the overlapped spectra of novel anti-asthmatic combination: Green-blue-white triple evaluation tools

This work represents different spectrophotometric techniques for concurrent quantification of Indacaterol (IND) and Mometasone furoate (MOM); co-formulated inhalation capsules to control asthma symptoms. Direct spectrophotometric (D0) approach was applied for IND assay. While, absorption factor (AF), ratio difference (RD), mean centering of the ratio spectra (MC), and continuous wavelet transform (CW) techniques were utilized for MOM quantification. The applied methods' validation was accomplished relative to the ICH guidelines. Within the linearity range of (4-20 μg/mL), these approaches provided accurate and precise assessment of IND and MOM in laboratory-synthetic mixtures and pharmaceutical formulation with determination coefficients higher than 0.9997. Moreover, the proposed methods demonstrated good detection and quantification levels. The respective LOD and LOQ for IND were (0.33 μg/mL) and (1.01 μg/mL). While, the LOD and LOQ for MOM were ranging from (0.16-0.30 μg/mL) and (0.47-0.91 μg/mL), respectively. Statistical comparison revealed no significant differences between the findings derived from the proposed methods and the reported one. The applied methods' environmental effect was cheeked using Analytical Greenness Calculator (AGREE), Blue Applicability Grade Index (BAGI), and Red-Green-Blue 12 (RGB12). All the utilized metrics showed reliable scores, approving that the proposed methods were adhered to the sustainability principles.

Catalyst-free synthesis of 1,2,3-triazole-N-oxide derivatives using tert-butyl nitrite: a novel strategy and synthetic applications

A simple, metal-free method has been developed to synthesize novel 1,2,3-triazole-N-oxide derivatives. In this reaction, t-BuONO serves as a NO source, with environmentally friendly solvents such as EtOH and H2O employed as additives. Control experiments provided valuable insights into the reaction mechanism. Furthermore, 1,2,3-triazole-N-oxides demonstrated versatility in synthetic transformations.

Catalyst-Free Synthesis of a Mechanically Tailorable, Nitric-Oxide-Releasing Organohydrogel and Its Derived Underwater Superoleophobic Coatings

Organohydrogels are an emerging class of soft materials that mimick the mechanical durability and organic solvent affinity of organogels and the biocompatibility and water swelling ability characteristics of hydrogels for prospective biomedical applications. This work introduces a facile, catalyst-free one-step chemical approach to develop an organohydrogel with impeccable antibiofouling properties following the epoxy-amine ring-opening reaction under ambient conditions. The mechanical properties of the as-fabricated organohydrogel can be tailored depending on the concentration of the epoxy-based cross-linker, from 0.10 to 1.12 MPa (compressive modulus). The affinity of the as-developed organohydrogel to both organic solvents and water was exploited to incorporate the antimicrobial nitric oxide donor (NO) molecule, S-nitroso-N-acetylpenicillamine (SNAP) from ethanol, and subsequently, the water-sensitive NO-releasing behavior of the organohydrogels was analyzed. The SNAP-incorporated organohydrogels release physiologically active levels of NO with 3.13 ± 0.27 × 10-10 and 0.36 ± 0.14 × 10-10 mol cm-2 min-1 flux of NO release observed at 0 and 24 h, respectively. The as-reported organohydrogel demonstrated excellent antibacterial activity against Escherichia coli and Staphylococcus aureus with >99% and >87% reduction, respectively, without eliciting any cytotoxicity concerns. Moreover, the organohydrogel with remarkable water uptake capacity was extended as a coating on different medically relevant polymers to demonstrate transparent underwater superoleophobicity. Thus, the facile synthesis of the reported organohydrogel and its derived underwater antifouling coating can open avenues for utility in biomedical, energy, and environmental applications.

Visible-Light-Driven Catalytic Dehalogenation of Trichloroacetic Acid and α-Halocarbonyl Compounds: Multiple Roles of Copper

Herein, we report the reaction development and mechanistic studies of visible-light-driven Cu-catalyzed dechlorination of trichloroacetic acid for the highly selective formation of monochloroacetic acid. Visible-light-driven transition metal catalysis via an inner-sphere pathway features the dual roles of transition metal species in photoexcitation and substrate activation steps, and a detailed mechanistic understanding of their roles is crucial for the further development of light-driven catalysis. This catalytic method, which features environmentally desired ascorbic acid as the hydrogen atom source and water/ethanol as the solvent, can be further applied to the dehalogenation of a variety of halocarboxylic acids and amides. Spectroscopic, X-ray crystallographic, and kinetic studies have revealed the detailed mechanism of the roles of copper in photoexcitation, thermal activation of the first C-Cl bond, and excited-state activation of the second C-Cl bond via excited-state chlorine atom transfer.

Preparation of antibacterial cellulose nanocrystals-graft-poly[2-(tert-butylamino) ethyl methacrylate] nanoparticles and their applications on creating wound dressings with a bacterial shielding property

Bacterial infections in wounds, especially in patients with chronic conditions like diabetic wounds, pose significant treatment challenges. Addressing the susceptibility to infection is crucial, and the development of functional dressings to prevent bacterial invasion has proven a promising strategy. Cellulose nanocrystals (CNCs), derived from bio-resources and functioning as nanoparticles (NPs), were modified with poly[2-(tert-butylamino) ethyl methacrylate] (PTA) through atom transfer radical polymerization (ATRP) to create CNCs-graft-PTA NPs (CNPs). Optimized CNPs exhibited enhanced antibacterial efficacy, excellent dispersity in environmentally friendly solvents, and notable biocompatibility. These CNPs were then applied to polypropylene non-woven fabrics (PPNWFs) via a straightforward dipping procedure. The integration of CNPs onto PPNWFs endowed them with exceptional antibacterial properties, a remarkable ability to shield against bacterial intrusion, and demonstrated biosafety through in vitro and in vivo assessments. With their desirable biomedical characteristics, CNP-modified PPNWFs emerge as a promising choice for the top layer in various functional dressings aimed at effectively treating wounds prone to infection.

Binary and Ternary Nanocomposite Membranes for Gas Separation Incorporating Finely Dispersed Carbon Nanotubes in a Polyether Block Amide Matrix

This work addressed the fine dispersion of Multiwalled Carbon Nanotubes (MWCNTs) in a polymer matrix to obtain Mixed Matrix Membranes (MMMs) suited for gas separation. Not-purified MWCNTs were effectively loaded within a polyether block amide (Pebax®2533) matrix, up to 24 wt%, using ultrasonication as well as a third component (polysorbate) in the dope solution. The obtained flexible thin films were investigated in terms of morphology, thermal properties, characterized by SEM, FT-IR, DSC, TGA, and gas permeation tests. The response to temperature variations of gas permeation through these nanocomposite specimens was also investigated in the temperature range of 25-55 °C. Defect-free samples were successfully obtained even at a significantly high loading of CNTs (up to 18 wt%), without a pre-treatment of the fillers. A remarkable enhancement of gas permeability upon the nanocarbons loading was reached, with a threshold value at a loading of ca. 7 wt%. The addition of polysorbates in the ternary MMMs further improves the dispersion of the filler, enhancing also the permselectivity of the membrane.

Selective lignin depolymerization via transfer hydrogenolysis using Pd/hydrotalcite catalysts: model compounds to whole biomass

Cleavage of lignin ether bonds via transfer hydrogenolysis is a promising route to valorize lignin, thus processes that use mild reaction conditions and exploit renewable hydrogen donor solvents (rather than molecular hydrogen) are economically advantageous. Herein we demonstrate the efficient catalytic transfer hydrogenolysis and tandem decarbonylation of lignin model compounds possessing aromatic ether bonds (α-O-4, β-O-4 and 4-O-5 linkages), over transition metal-modified Pd hydrotalcite catalysts with ethanol as the hydrogen donor and solvent. Quantitative conversions and yields were attained for all model compounds, except for 4-O-5 models, which possess inherently strong sp2 C-O bonds. The latter demonstrates the utility of Pd hydrotalcite catalysts for transfer hydrogenolysis of model compounds. This process was employed to achieve whole pine biomass delignification with 97% yield and a 22% phenolic monomer yield, with 64% selectivity for 4-(3-hydroxypropyl)-2-methoxyphenol.

High Pressure Extraction as a Green Alternative to the Conventional Sunflower Oil (Helianthus annuus) Production Process - Extraction with Pressurized Ethanol in an Intermittent Process and with Supercritical Fluid

This research explores green-technology alternatives to extract vegetable oils as alternatives to hexane, a non-renewable solvent, focussing on sunflower oil. It compares pressurized liquid extraction (PLE) with ethanol and supercritical fluid extraction (SFE) with CO2. Both processes aim to maximize oil yield, tocopherol content (α, β, γ, and δ), fatty acid profile (FA), and triacylglycerol (TAG) composition. Results show that SFE at 32 MPa achieves an 87.58% oil recovery, while PLE at 84 °C achieves 93.93%. PLE with ethanol extracts polar minority compounds along with the oil due to its higher temperature, favoring extraction. The total tocopherol content is 91.17 mg/100 g of oil in optimized SFE conditions, with α-tocopherol extraction influenced by temperature, γ and δ-tocopherol by pressure. PLE yields 83.16 mg/100 g of oil in tocopherols influenced less by process variables. The fatty acid (FA) profile do not vary in the oils obtained from different processes or based on the variables within each process, with linoleic and oleic acids being the most abundant. Similarly, triacylglycerols (TAGs) C54:5 and C54:6 are predominant. The optimization of SFE and PLE processes indicates a strong potential for using green solvents in the extraction of tocopherol-rich sunflower oil.

Alternative green solvents associated with ultrasound-assisted extraction: A green chemistry approach for the extraction of carotenoids and chlorophylls from microalgae

This study proposes a method for the ultrasonic extraction of carotenoids and chlorophyll from Scenedesmus obliquus and Arthrospira platensis microalgae with green solvents. Ethanol and ethanolic solutions of ionic liquids were tested with a variety of extraction parameters, including number of extractions, time of extraction, and solid-liquid ratio R(S/L), to determine the optimal conditions. After selecting the most effective green solvent (ethanol), the process conditions were established: R(S/L) of 1:10, three extraction cycles at 3 min each), giving an extraction yield of 2602.36 and 764.21 μgcarotenoids.gdried biomass-1; and 22.01 and 5.81 mgchlorophyll.gdried biomass-1 in S. obliquus and A. platensis, respectively. The carotenoid and chlorophyll extracts obtained using ethanol were shown to be potent scavengers of peroxyl radical, being 5.94 to 26.08 times more potent α-tocopherol. These findings pave the way for a green strategy for valorizing microalgal biocompounds through efficient and environmentally friendly technological processes.

Waste Valorization in a Sustainable Bio-Based Economy: The Road to Carbon Neutrality

The development of sustainable chemistry underlying the quest to minimize and/or valorize waste in the carbon-neutral manufacture of chemicals is followed over the last four to five decades. Both chemo- and biocatalysis have played an indispensable role in this odyssey. in particular developments in protein engineering, metagenomics and bioinformatics over the preceding three decades have played a crucial supporting role in facilitating the widespread application of both whole cell and cell-free biocatalysis. The pressing need, driven by climate change mitigation, for a drastic reduction in greenhouse gas (GHG) emissions, has precipitated an energy transition based on decarbonization of energy and defossilization of organic chemicals production. The latter involves waste biomass and/or waste CO2 as the feedstock and green electricity generated using solar, wind, hydroelectric or nuclear energy. The use of waste polysaccharides as feedstocks will underpin a renaissance in carbohydrate chemistry with pentoses and hexoses as base chemicals and bio-based solvents and polymers as environmentally friendly downstream products. The widespread availability of inexpensive electricity and solar energy has led to increasing attention for electro(bio)catalysis and photo(bio)catalysis which in turn is leading to myriad innovations in these fields.

The Influence of the Comonomer Ratio and Reaction Temperature on the Mechanical, Thermal, and Morphological Properties of Lignin Oil-Sulfur Composites

Although lignin is a plentiful biomass resource, it continually exists as an underutilized component of biomass material. Elemental sulfur is another abundant yet underutilized commodity produced as a by-product resulting from the refining of fossil fuels. The current study presents a strategy for preparing five durable composites via a simple one-pot synthesis involving the reaction of lignin oil and elemental sulfur. These lignin oil-sulfur composites LOSx@T (where x = wt. % sulfur, ranging from 80 to 90, and T represents the reaction temperature in °C) were prepared via the reaction of elemental sulfur and lignin oil (LO) with elemental sulfur. The resulting composites could be remelted and reshaped several times without the loss of mechanical strength. Mechanical, thermal, and morphological studies showed that LOSx@T possesses properties competitive with some mechanical properties of commercial building materials, exhibiting favorable compressive strengths (22.1-35.9 MPa) and flexural strengths (5.7-6.5 MPa) exceeding the values required for many construction applications of ordinary Portland cement (OPC) and brick formulations. While varying the amount of organic material did not result in a notable difference in mechanical strength, increasing the reaction temperature from 230 to 300 °C resulted in a significant increase in compressive strength. The results reported herein reveal potential applications of both lignin and waste sulfur during the ongoing effort toward developing recyclable and sustainable building materials.

Hydrogen-transfer strategy in lignin refinery: Towards sustainable and versatile value-added biochemicals

Lignin, the most prevalent natural source of polyphenols on Earth, offers substantial possibilities for the conversion into aromatic compounds, which is critical for attaining sustainability and carbon neutrality. The hydrogen-transfer method has garnered significant interest owing to its environmental compatibility and economic viability. The efficacy of this approach is contingent upon the careful selection of catalytic and hydrogen-donating systems that decisively affect the yield and selectivity of the monomeric products resulting from lignin degradation. This paper highlights the hydrogen-transfer technique in lignin refinery, with a specific focus on the influence of hydrogen donors on the depolymerization pathways of lignin. It delineates the correlation between the structure and activity of catalytic hydrogen-transfer arrangements and the gamut of lignin-derived biochemicals, utilizing data from lignin model compounds, separated lignin, and lignocellulosic biomass. Additionally, the paper delves into the advantages and future directions of employing the hydrogen-transfer approach for lignin conversion. In essence, this concept investigation illuminates the efficacy of the hydrogen-transfer paradigm in lignin valorization, offering key insights and strategic directives to maximize lignin's value sustainably.

Synergy of Oxygen Vacancies and Base Sites for Transfer Hydrogenation of Nitroarenes on Ceria Nanorods

CeO2 nanorod based catalysts for the base-free synthesis of azoxy-aromatics via transfer hydrogenation of nitroarenes with ethanol as hydrogen donor have been synthesized and investigated. The oxygen vacancies (Ov ) and base sites are critical for their excellent catalytic properties. The Ov , i.e., undercoordinated Ce cations, serve as the sites to activate ethanol and nitroarenes by lowering the energy barrier to transfer hydrogen from α-Csp3 -H in ethanol to the nitro group coupling it to the redox reactions between Ce3+ and Ce4+ . At the same time, the base sites catalyze the condensation step to selectively produce azoxy-aromatics. The catalytic route opens a much improved way to use non-noble metal oxides without additives for the selective functional group reduction and coupling reactions.

A versatile approach for one-pot synthesis of hybridized quinolines linked to fused N-containing heterocycles in water

Here, highly efficient one-pot protocols for the synthesis of structurally diverse fused N-containing heterocycles containing 2-chloroquinoline employing 1,1-bis(methylsulfanyl)-2-nitroethene, diamines, 2-chloroquinoline-3-carbaldehydes and dimedone/Meldrum's acid in green media in the absence of catalyst are reported. The current report proposes sustainable, simple, four-component and straightforward strategies for generating interesting N-containing heterocyclic compounds from a range of diamines and 2-chloroquinoline-3-carbaldehydes. The utilization of water as green media furnishes sustainability by preventing the usage of toxic solvent. A range of quinoline-containing aldehydes and diamines can be converted to two types of products with respect to using dimedone or Meldrum's acid via an inexpensive, one-pot and easy route.

Rigorous pH measurement in non-aqueous solution: measurement method and reference values in ethanol

The recently introduced unified pH ([Formula: see text]) concept enables rigorous pH measurements in non-aqueous and mixed media while at the same time maintaining comparability to the conventional aqueous pH scale. However, its practical application is hindered by a shortage of reference [Formula: see text] values. In order to improve this situation, the European Metrology Research Project (EMPIR) UnipHied ("Realisation of a UnipHied pH scale") launched an interlaboratory comparison among highly experienced electrochemistry expert laboratories to assign the first such reference [Formula: see text] values by adopting an extensive statistical treatment of the reported measurement data: to phosphate buffer in water-ethanol mixture (50 wt% of ethanol) and ammonium formate buffer in pure ethanol. Two different measurement setups - one capable of being easily adopted in industrial applications - have been used to demonstrate the robustness of [Formula: see text] measurement. This is an important step towards wider adoption of the [Formula: see text] concept in practice, like liquid chromatography, biofuels analysis and electrocatalysis.

Branched copolymer surfactants impart thermoreversible gelation to LAPONITE® gels

This investigation seeks to integrate LAPONITE® clay gels with thermoresponsive branched copolymer surfactants (BCSs) to develop advanced functional materials with temperature-induced sol-gel behaviour. It is known that a diverse range of molecules adsorb strongly to clays which may be used to control liberation of the species in healthcare applications, and as such the development of polymer/clay hybrid materials which can add function to the native clay behaviour are of great interest. BCS were synthesised with a structure that encompasses poly(ethylene glycol)methacrylate (PEGMA), ethylene glycol dimethacrylate (EGDMA), and dodecanethiol (DDT), conferring versatile and tuneable thermoresponsive attributes. Systematic modulation of the monomer : DDT/initiator ratio was used to facilitate the synthesis of BCS architectures spanning a range of molecular weights. Through application of small-amplitude oscillatory shear (SAOS) rheology and small-angle neutron scattering (SANS) in conjunction with controlled temperature variations, the sol-gel transition dynamics of these nanocomposite materials were elucidated. Complementary insights into the mechanisms underpinning this transition and temperature-induced alterations in the constituents are gleaned through the utilization of SANS techniques employing contrast-matching methodologies to mitigate clay and polymer scattering interference. It is found that heating systems from room- to body- temperature induces self-assembly of BCS in the bulk aqueous phase with concurrent structuration of clay in gel-forming samples with lower number average molecular weight (Mn). SANS study unpicks this phenomenon to find that gelation occurs with concurrent aggregation of BCS in the bulk, inducing clay-clay interactions only in lower Mn BCS systems with large nanoaggregates.

Label-free green estimation of atenolol and ivabradine hydrochloride in pharmaceutical and biological matrices by synchronous spectrofluorimetry

In this work, a label-free, rapid, and sensitive synchronous spectrofluorometric method was implemented to assay atenolol (ATL) and ivabradine hydrochloride (IVB) in pharmaceutical and biological matrices. Simultaneous determination of ATL and IVB by conventional spectrofluorometry cannot be implemented because of the clear overlap of the emmision spectra of ATL and IVB. To overcome this problem, synchronous fluorescence measurements at a constant wavelength difference (Δλ) combined with mathematical derivatization of the zero order spectra were perforemed. The results indicated a good resolution between emission spectra of the studied drugs when the first-order derivative of the synchronous fluorescence scans at Δλ = 40 nm was conducted using ethanol as the optimum solvent which is less hazardous than other organic solvents such as methanol and acetonitrile, keeping the method safe and green. The amplitudes of the first derivative synchronous fluorescent scans of ATL and IVB in ethanol were monitored at 286 and 270 nm to simultaneously estimate ATL and IVB, respectively. Method optimisation was conducted by assessing different solvents, buffer pHs, and surfactants. The optimum results were obtained when ethanol was utilized as a solvent without using any other additives. The developed method was linear over concentration ranges of 10.0-250.0 ng mL^-1 for IVB and 100.0-800.0 ng mL^-1 for ATL with detection limits of 3.07 and 26.49 ng mL^-1 for IVB and ATL, respectively. The method was utilized to assay the studied drugs in their dosages and in human urine samples with acceptable % recoveries and RSD values. The greenness of the method was implemented by three approaches involving the recently reported metric (AGREE) which ensured the eco-freindship and safety of the method.

Autohydrolysis Application on Vine Shoots and Grape Stalks to Obtain Extracts Enriched in Xylo-Oligosaccharides and Phenolic Compounds

Agronomic practices and the winemaking process lead to the production of considerable quantities of waste and by-products. These are often considered waste with negative effects on environmental sustainability. However, vine shoots and grape stalks can be reused, representing a potential source of xylo-oligosaccharides and polyphenols. In this context, the purpose of this work was to obtain enriched extracts using three different autohydrolysis treatments with (i) H2O, (ii) H2O:EtOH, and (iii) H2O:Amberlyst. The obtained extracts were characterized by their xylo-oligosaccharide and polyphenol profiles using LC-MS techniques. The use of ethanol during autohydrolysis allowed for greater extraction of xylan-class compounds, especially in vine shoot samples, while an increase in antioxidant activity (128.04 and 425.66 µmol TE/g for ABTS and DPPH, respectively) and in total phenol content (90.92 mg GAE/g) was obtained for grape stalks.

Reductive Catalytic Fractionation of Abies Wood into Bioliquids and Cellulose with Hydrogen in an Ethanol Medium over NiCuMo/SiO2 Catalyst

Noble metal-based catalysts are widely used to intensify the processes of reductive fractionation of lignocellulose biomass. In the present investigation, we proposed for the first time using the inexpensive NiCuMo/SiO2 catalyst to replace Ru-, Pt-, and Pd-containing catalysts in the process of reductive fractionation of abies wood into bioliquids and cellulose products. The optimal conditions of abies wood hydrogenation were selected to provide the effective depolymerization of wood lignin (250 °C, 3 h, initial H2 pressure 4 MPa). The composition and structure of the liquid and solid products of wood hydrogenation were established. The NiCuMo/SiO2 catalyst increases the yield of bioliquids (from 36 to 42 wt%) and the content of alkyl derivatives of methoxyphenols, predominantly 4-propylguaiacol and 4-propanolguaiacol. A decrease in the molecular mass and polydispersity (from 1870 and 3.01 to 1370 Da and 2.66, respectively) of the liquid products and a threefold increase (from 9.7 to 36.8 wt%) in the contents of monomer and dimer phenol compounds were observed in the presence of the catalyst. The solid product of catalytic hydrogenation of abies wood contains up to 73.2 wt% of cellulose. The composition and structure of the solid product were established using IRS, XRD, elemental and chemical analysis. The data obtained show that the catalyst NiCuMo/SiO2 can successfully replace noble metal catalysts in the process of abies wood reductive fractionation into bioliquids and cellulose.

Distribution in marine fish and EDI estimation of contaminants of emerging concern by vortex-assisted matrix solid-phase dispersion and HPLC-MS/MS

Due to their persistence or continuous discharge, toxic substances are present in the aquatic environment, and can bioaccumulate and biomagnify in the food web, generating a significant ecological risk and a threat to human health. The present study assess the occurrence and tissue (muscle, liver, stomach and gills) distribution of 59 anthropogenic contaminants of emerging concern (CECs) in marine fish from Brazil. A simpler and faster analytical methodology based on vortex-assisted matrix solid-phase dispersion (VA-MSPD) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was developed and validated. Limits of quantification ranged from 3.31 to 114 ng g^-1 dw with recovery rates between 60 and 140 % and relative standard deviation below 20 %. The ultraviolet filters 4-hydroxybenzophenone (4HB) (benzophenone-3 metabolite) and benzocaine (Et-PABA), and the antibacterial salicylic acid were frequently accumulated in muscle and liver at concentrations between 39.5 and 21.0 ngg^-1 dw. The determined concentrations resulted to be lower than the tolerable daily intake recommended by the European Food Safety Authority (EFSA).

Efficacy of Green Extracting Solvents on Antioxidant, Xanthine Oxidase, and Plant Inhibitory Potentials of Solid-Based Residues (SBRs) of Cordyceps militaris

Solid-based residues (SBRs) of Cordyceps militaris are often considered as waste after the cultivation of the fruiting body. To demonstrate the value of this by-product, different ratios of two favorable green solvents (EtOH and water) were employed to optimize the yields of cordycepin (Cor) and adenosine (Ado) and investigate relevant activities of plant growth inhibition (allelopathy), antioxidants, and xanthine oxidase. The SBR extracts of 60% EtOH-40% water (W4) and 40% EtOH-60% water (W6) exhibited the highest antioxidant activity as well as yielded the optimum content of Cor and Ado. The W4 and Wt (hot water) exhibited maximum inhibitory effects on the growth of Raphanus sativus (radish), Lactuca sativa (lettuce) and two noxious weeds, Echinochloa crus-galli (barnyard grass) and Bidens pilosa (beggarticks). Furthermore, GC-MS scan analysis revealed the presence of 14 major compounds in the SBRs. W4 is the best solvent to optimize yields of Cor and Ado, as well as having the strongest levels of antioxidant activity, xanthine oxidase, and growth-inhibitory activity. This study reveals that SBRs are a potential source of medicinal and agricultural utilization.

Catalytic Wood Fractionation into Chemicals in Supercritical Ethanol and n-Heptane: Potential and Limitations

Direct selective wood fractionation into chemicals is an approach that has attracted recent attention. The application of sub- and supercritical (SC) alcohols to fractionate wood into solid cellulose and liquefy phenolic monomers is a process now widely known as “lignin first”. It is justified to study the potential of other SC organic solvents of variable polarities. Herein, we compare the abilities of SC ethanol and SC n-heptane to fractionate pine wood near their critical point. While near-critical ethanol has more affinity for lignin fraction, we show that near-critical n-heptane has preference for carbohydrate deconstruction. If SC ethanol favors biooil formation which contains important ethyl/ethoxy groups, the alkane greatly favors solid carbon products. The impact of addition of heterogeneous catalysts (acid, basic and Cu-based catalysts) on wood fractionation and light chemicals formation was investigated deeply in SC ethanol. In SC ethanol, catalysts favor light liquid products such as esters at the expense of biooil with a total oxygenates yield of 33 wt% relative to carbohydrates over β zeolite. However, we show that depending on the catalysts’ nature, wood components fractionation was completely changed, and this is particularly true with solid acid catalysts which promote cellulose deconstruction and the formation of solid carbon products. It is proposed that liquid products’ accumulation in the autoclave, in particular water, is at the origin of the wood fractionation changes which preclude its control by the choice of the SC organic solvent and conditions. Moreover, all the catalysts underwent severe leaching, which also contributed to the wood component fractionation changes.

High-Purity Fucoxanthin Can Be Efficiently Prepared from Isochrysis zhangjiangensis by Ethanol-Based Green Method Coupled with Octadecylsilyl (ODS) Column Chromatography

The exploitation of new economically valuable microalgae as a sustainable source of minor high-value products can effectively promote the full utilization of microalgae. The efficient preparation of minor products from microalgae remains the challenge, owing to the coexistence of various components with a similar polarity in the microalgae biomass. In this study, a novel approach based on the sustainable-oriented strategy for fucoxanthin (FX) production was proposed, which consisted of four steps, including the culture of microalga, ethanol extraction, ODS column chromatography, and ethanol precipitation. The high-purity FX (around 95%) was efficiently obtained in a total recovery efficiency of 84.28 ± 2.56%. This study reveals that I. zhangjiangensis is a potentially promising feedstock for FX production and firstly provides a potentially eco-friendly method for the scale-up preparation of FX from the microalga I. zhangjiangensis.

A Comprehensive Optimization of Ultrasound-Assisted Extraction for Lycopene Recovery from Tomato Waste and Encapsulation by Spray Drying

This study aimed to extract bioactive compounds from tomato waste through ultrasound-assisted extraction (UAE), using ethanol as solvent. Process optimization was carried out by a central composite design of 33 runs for response surface modelling, simultaneously analyzing the effect of temperature (T), time (t), volume (V), liquid-to-solid ratio (L/S), amplitude (A), the pulser duration (on), and their interaction. The best conditions found by the desirability method (T = 65 °C, t = 20 min, L/S = 72 mL/g, A = 65%, on = 33 s, V = 90 mL) were experimentally verified, leading to the production of an extract with interesting properties (total carotenoids of 1408 ±14 µglycopene equivalents/g, lycopene yield of 1536 ± 53 µg/g, 36.1 ± 0.9 µgtrolox equivalents/g as antiradical power). Due to the instability of lycopene, the extract encapsulation by spray drying was undertaken using inulin and maltodextrins as coating agents. The evaluation of wall material composition provided high product recovery (73%), a high content of encapsulated compared to superficial lycopene (15.3 ± 2.9 and 0.30 ± 0.02 µg/g), and a product with good water solubility. The novelty of this work concerned the simultaneous study of the effect and interdependences of the UAE parameters, and the use of inulin to enhance the properties of microparticles.

Antioxidant and anti-inflammatory polyphenols in ultrasound-assisted extracts from salvilla (Buddleja scordioides Kunth)

Salvilla is a widely distributed plant used in treatments against gastrointestinal disorders due to its phenolic antioxidant and anti-inflammatory potential. Major yield and quality of bioactive polyphenols must be obtained with no degradation during suitable processes such as Ultrasound-Assisted Extraction (UAE), which allows an efficient extraction of metabolites at appropriate parameter conditions. Salvilla extractions were made using UAE and aqueous ethanolic solutions. Variables used in UAE were sonication time, wave amplitude and percentage of ethanol in solvent. Extracts were tested for total flavonoids, antioxidant activity (ABTS, FRAP and ORAC) and an identification and quantification of phenolic compounds was carried out by UPLC-PDA-ESI-MS/MS. Once elected the better extraction conditions, an anti-inflammatory test was performed for this treatment. As a result, total flavonoids content in extracts was 147 to 288 µg catechin equivalents/mg of dry salvilla extract. All extracts have shown good antioxidant activity (86 to 280 mM Trolox eq/mg dry salvilla extract). Flavonoids contents by chromatography were higher than hydroxybenzoic and hydroxycinnamic acids specially the flavone, flavanol and flavanone groups. Treatment T6 (75% ethanol, 30% amplitude and 10 min extraction time) was the best extract in terms of significant flavonols, antioxidant activity, and higher anti-inflammatory potential.

A Green Extraction Method to Achieve the Highest Yield of Limonin and Hesperidin from Lime Peel Powder (Citrus aurantifolia)

Green extraction is aimed at reducing energy consumption by using renewable plant sources and environmentally friendly bio-solvents. Lime (Citrus aurantifolia) is a rich source of flavonoids (e.g., hesperidin) and limonoids (e.g., limonin). Manufacturing of lime products (e.g., lime juice) yields a considerable amount of lime peel as food waste that should be comprehensively exploited. The aim of this study was to develop a green and simple extraction method to acquire the highest yield of both limonin and hesperidin from the lime peel. The study method included ethanolic-aqueous extraction and variable factors, i.e., ethanol concentrations, pH values of solvent, and extraction temperature. The response surface methodology was used to optimize extraction conditions. The concentrations of limonin and hesperidin were determined by using UHPLC-MS/MS. Results showed that the yields of limonin and hesperidin significantly depended on ethanol concentrations and extraction temperature, while pH value had the least effect. The optimal extraction condition with the highest amounts of limonin and hesperidin was 80% ethanol at pH 7, 50 °C, which yields 2.072 and 3.353 mg/g of limonin and hesperidin, respectively. This study illustrates a green extraction process using food waste, e.g., lime peel, as an energy-saving source and ethanol as a bio-solvent to achieve the highest amount of double bioactive compounds.

SCLAREIN (SCLAREol contained in zeIN) nanoparticles: Development and characterization of an innovative natural nanoformulation

Sclareol is a labdane diterpene which carries on a broad range of biological activities. However, its poor water solubility and bioavailability are the foremost drawbacks that limit its application in therapeutics. The purpose of this investigation was to develop a natural nanoformulation made up of a biopolymer i.e. zein and sclareol in order to address this issue and to enhance the pharmacological efficacy of the drug. The sclarein nanoparticles (sclareol-loaded zein nanosystems) showed a typical monomodal pattern, characterized by a mean diameter of ~120 nm, a narrow size distribution and a surface charge of ~-30 mV. The evaluation of the entrapment efficiency and the drug-loading capacity of the nanosystems demonstrated the noteworthy ability of the protein matrix to hold sclareol while allowing a gradual release of the compound over time. The nanosystems increased the cytotoxicity of sclareol at a drug concentration of ≥5 μM with respect to the free compound after just 24 h incubation against various cancer cell lines. Indeed, the interaction of tritiated sclarein formulations with cells showed a time-dependent cell uptake of the nanosystems commencing as early as 1 h from the onset of incubation, favouring a significant decrease of the efficacious concentration of the drug.

Thermal Conversion of Flax Shives in Sub- and Supercritical Ethanol in the Presence of Ru/C Catalyst

Thermal conversion of flax shives was studied in sub- and supercritical ethanol medium at 225 and 250 °C in the presence of the bifunctional catalyst 3% Ru/C. The use of 3% Ru/C catalyst in the process of thermal conversion of flax shives in supercritical ethanol was found to increase the conversion of the shives by 27% and the yield of liquid products by 10%. The use of 3% Ru/C catalyst in sub- and supercritical ethanol led to the destruction of both lignin and cellulose. The degree of delignification in the non-catalytic thermal conversion increased upon transition from subcritical (225 °C) to supercritical (250 °C) conditions. Main monomeric products of the thermal conversion process were guaiacylpropene or guaiacylpropane depending on the process temperature. In the presence of Ru/C catalyst, the molecular weight distribution was shifted towards an increase in the content of monomeric compounds in the liquid products.

Highly Efficient Semi-Continuous Extraction and In-Line Purification of High β-O-4 Butanosolv Lignin

Innovative biomass fractionation is of major importance for economically competitive biorefineries. Lignin is currently severely underutilized due to the use of high severity fractionation methodologies that yield complex condensed lignin that limits high-value applicability. Mild lignin fractionation conditions can lead to lignin with a more regular C-O bonded structure that has increased potential for higher value applications. Nevertheless, such extraction methodologies typically suffer from inadequate lignin extraction efficiencies and yield. (Semi)-continuous flow extractions are a promising method to achieve improved extraction efficiency of such C-O linked lignin. Here we show that optimized organosolv extraction in a flow-through setup resulted in 93-96% delignification of 40 g walnut shells (40 wt% lignin content) by applying mild organosolv extraction conditions with a 2 g/min flowrate of a 9:1 n-butanol/water mixture with 0.18 M H2SO4 at 120°C in 2.5 h. 85 wt% of the lignin (corrected for alcohol incorporation, moisture content and carbohydrate impurities) was isolated as a powder with a high retention of the β-aryl ether (β-O-4) content of 63 linking motifs per 100 C9 units. Close examination of the isolated lignin showed that the main carbohydrate contamination in the recovered lignin was butyl-xyloside and other butoxylate carbohydrates. The work-up and purification procedure were investigated and improved by the implementation of a caustic soda treatment step and phase separation with a continuous integrated mixer/separator (CINC). This led to a combined 75 wt% yield of the lignin in 3 separate fractions with 3% carbohydrate impurities and a very high β-O-4 content of 67 linking motifs per 100 C9 units. Analysis of all the mass flows showed that 98% of the carbohydrate content was removed with the inline purification step, which is a significant improvement to the 88% carbohydrate removal for the traditional lignin precipitation work-up procedure. Overall we show a convenient method for inline extraction and purification to obtain high β-O-4 butanosolv lignin in excellent yields.

Rapid Depolymerization of Decrystallized Cellulose to Soluble Products via Ethanolysis under Mild Conditions

Efficient cellulose depolymerization is a major bottleneck for economical production of second-generation biofuels. In this work, crystalline cellulose was subjected to sequential ball milling and ethanolysis as a mild and selective depolymerization approach. Ball milling and ethanolysis resulted in 38±1 % cellulose conversion, with 24 % ethyl-glucopyranoside as the main identified and quantified product and negligible side reaction of the ethanol solvent to form diethyl ether. In comparison, ethanolysis of the original cellulose resulted in only 3±1 % conversion. Additional soluble products from cellulose ethanolysis included carbohydrate isomers and oligomers, differing from the products obtained from hydrolysis. X-ray diffraction and nuclear magnetic resonance spectroscopy revealed increased crystallinity post-reaction, retarding further depolymerization. Hot liquid water extracted soluble oligomers from the ethanolyzed cellulose, suggesting formation of a nanoscale barrier of crystalline cellulose that traps soluble products during ethanolysis. Use of cellulose-swelling co-solvents and repeated mechanical decrystallization both proved effective at increasing cellulose conversion and soluble product yields. Repeated ball milling and ethanolysis resulted in 62±1 % cellulose conversion. Ethanolysis of decrystallized cellulose has potential for rapid (<2 h) de-polymerization at mild conditions.

Supercritical Fluids: A Promising Technique for Biomass Pretreatment and Fractionation

Lignocellulosic biomasses are primarily composed of cellulose, hemicelluloses and lignin and these biopolymers are bonded together in a heterogeneous matrix that is highly recalcitrant to chemical or biological conversion processes. Thus, an efficient pretreatment technique must be selected and applied to this type of biomass in order to facilitate its utilization in biorefineries. Classical pretreatment methods tend to operate under severe conditions, leading to sugar losses by dehydration and to the release of inhibitory compounds such as furfural (2-furaldehyde), 5-hydroxy-2-methylfurfural (5-HMF), and organic acids. By contrast, supercritical fluids can pretreat lignocellulosic materials under relatively mild pretreatment conditions, resulting in high sugar yields, low production of fermentation inhibitors and high susceptibilities to enzymatic hydrolysis while reducing the consumption of chemicals, including solvents, reagents, and catalysts. This work presents a review of biomass pretreatment technologies, aiming to deliver a state-of-art compilation of methods and results with emphasis on supercritical processes.

Efficient Mild Organosolv Lignin Extraction in a Flow-Through Setup Yielding Lignin with High β-O-4 Content

Current lignin fractionation methods use harsh conditions that alter the native lignin structure, resulting in a recalcitrant material which is undesired for downstream processing. Milder fractionation processes allow for the isolation of lignins that are high in β-aryl ether (β-O-4) content, however, at reduced extraction efficiency. The development of improved lignin extraction methods using mild conditions is therefore desired. For this reason, a flow-through setup for mild ethanosolv extraction (120 °C) was developed. The influence of acid concentration, ethanol/water ratio, and the use of other linear alcohol co-solvents on the delignification efficiency and the β-O-4 content were evaluated. With walnut shells as model feedstock, extraction efficiencies of over 55% were achieved, yielding lignin with a good structural quality in terms of β-O-4 linking motifs (typically over 60 per 100 aromatic units). For example, lignin containing 66 β-O-4 linking motifs was obtained with an 80:20 n-propanol/water ratio, 0.18 M H₂SO₄ with overall a good extraction efficiency of 57% after 5 h. The majority of the lignin was extracted in the first 2 hours and this lignin showed the best structural quality. Compared to batch extractions, both higher lignin extraction efficiency and higher β-O-4 content were obtained using the flow setup.

One-pot transformation of lignocellulosic biomass into crude bio-oil with metal chlorides via hydrothermal and supercritical ethanol processing

Grape seeds were deconstructed in both hydrothermal and supercritical ethanol media with a combination of two metal chlorides (TiCl₄:MgCl₂) to produce bio-oils. The use of metal chloride additives in supercritical ethanol achieved the highest bio-oil yield of 49.2 wt% (300 °C, 30 min). Both the hydrothermal and supercritical ethanol deconstruction with the additives (TiCl₄:MgCl₂ = 4 mmol:4mmol) produced the bio-oils with a higher heating value (HHV) of 35 MJ/Kg. Gas chromatography-mass spectrometry (GC-MS) analysis of the bio-oils showed that the major products in bio-oils from the hydrothermal deconstruction were acids while the majority products in bio-oils form the supercritical ethanol deconstruction were esters. Nuclear magnetic resonance (NMR) data of the bio-oils suggested that both hydrothermal and supercritical ethanol deconstruction with metal chlorides significantly reduced the non-condensed OH and oxygenated lignin sub-units in bio-oils; while only supercritical ethanol deconstruction with metal chlorides reduced the aliphatic OH and O-alkylated structures in bio-oils.