Mechanochemistry and oleochemistry: a green combination for the production of high-value small chemicals.

Mechanochemistry and oleochemistry and their combination have been known for centuries. Nevertheless, bioeconomy and circular economy concepts is much more recent and has motivated a regain of interest of dedicated research to improve alternative technologies for the valorization of biomass feedstocks. Accordingly, this review paper aims essentially at outlining recent breakthroughs obtained in the field of mechanochemistry and oleochemicals such as triglycerides, fatty acids, and glycerol derivatives. The review discusses advances obtained in the production of small chemicals derived from oils with a brief overview of vegetable oils, mechanochemistry and the use of mechanochemistry for the synthesis of biodiesel, lipidyl-cyclodextrine, dimeric and labelled fatty acids, calcium diglyceroxide, acylglycerols, benzoxazine and solketal. The paper also briefly overviews advances and limits for an industrial application.

Photoredox-Catalyzed gem-Difluoromethylenation of Aliphatic Alcohols with 1,1-Difluoroalkenes to Access α,α-Difluoromethylene Ethers.

A switchable synthesis of alcohols and ketones bearing a CF2-OR scaffold using visible-light promotion is described. The method of PDI catalysis is characterized by its ease of operation, broad substrate scopes, and the ability to switch between desired products without the need for transition metal catalysts. The addition or absence of a base plays a key role in controlling the synthesis of the major desired products.

Steam explosion as sustainable biomass pretreatment technique for biofuel production: Characteristics and challenges.

The biorefining process of lignocellulosic biomass has recently emerged as one of the most profitable biofuel production options. However, pretreatment is required to improve the recalcitrant lignocellulose's enzymatic conversion efficiency. Among biomass pretreatment methods, the steam explosion is an eco-friendly, inexpensive, and effective approach to pretreating biomass, significantly promoting biofuel production efficiency and yield. This review paper critically presents the steam explosion's reaction mechanism and technological characteristics for lignocellulosic biomass pretreatment. Indeed, the principles of steam explosion technology for lignocellulosic biomass pretreatment were scrutinized. Moreover, the impacts of process factors on pretreatment efficiency and sugar recovery for the following biofuel production were also discussed in detail. Finally, the limitations and prospects of steam explosion pretreatment were mentioned. Generally, steam explosion technology applications could bring great potential in pretreating biomass, although deeper studies are needed to deploy this method on industrial scales.

Green and rapid and instrumental one-pot method for the synthesis of imidazolines having potential anti-SARS-CoV-2 main protease activity.

The Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) is responsible for ongoing epidemics in humans and some other mammals and has been declared a public health emergency of international concern. In this project, several small non-peptide molecules were synthesized to inhibit the major proteinase (Mpro) of SARS-CoV-2 using rational strategies of drug design and medicinal chemistry. Mpro is a key enzyme of coronaviruses and plays an essential role in mediating viral replication and transcription in human lung epithelial and stem cells, making it an attractive drug target for SARS-CoV. The antiviral potential of imidazoline derivatives as inhibitors of (SARS-CoV-2) Mpro was evaluated using in-silico techniques such as molecular docking simulation, molecular dynamics (MD), and ADMET prediction. The docking scores of these imidazoline derivatives were compared to that of the N3 crystal inhibitor and showed that most of these compounds, particularly compound E07, interacted satisfactorily in the active site of the coronavirus and strongly interacted with the residues (Met 165, Gln 166, Met 165, His 41, and Gln 189). Furthermore, the results were confirmed by MD simulations after exposure to long-term MD simulations and ADMET predictions.

Microalgae bio-oil production by pyrolysis and hydrothermal liquefaction: Mechanism and characteristics.

Microalgae have great potential in producing energy-dense and valuable products via thermochemical processes. Therefore, producing alternative bio-oil to fossil fuel from microalgae has rapidly gained popularity due to its environmentally friendly process and elevated productivity. This current work aims to review comprehensively the microalgae bio-oil production using pyrolysis and hydrothermal liquefaction. In addition, core mechanisms of pyrolysis and hydrothermal liquefaction process for microalgae were scrutinized, showing that the presence of lipids and proteins could contribute to forming a large amount of compounds containing O and N elements in bio-oil. However, applying proper catalysts and advanced technologies for the two aforementioned approaches could improve the quality, heating value, and yield of microalgae bio-oil. In general, microalgae bio-oil produced under optimal conditions could have 46 MJ/kg heating value and 60% yield, indicating that microalgae bio-oil could become a promising alternative fuel for transportation and power generation.

Monoclonal antibodies in breast cancer: A critical appraisal.

In breast cancer, mAbs can play multifunctional roles like targeting cancer cells, sometimes directly attacking them, helping in locating and delivering therapeutic drugs to targets, inhibiting cell growth and blocking immune system inhibitors, etc. Monoclonal antibodies are also one of the important successful treatment strategies especially against HER2 but they have not been explored much for other types of breast cancers especially in triple negative breast cancers. Monoclonal antibodies impact the feasibility of antigen specificity, bispecific and trispecific mAbs have opened new doors for more targeted specific efficacy. Monoclonal antibodies can be used diversly and with efficacy as compared to other methods of treatment thus maining it a suitable candidate for breast cancer treatment. However, mAbs treatment also causes various side effects such as fever, trembling, fatigue, headache and muscle pain, nausea/vomiting, difficulty in breathing, rashes and bleeding. Understanding the pros and cons of this strategy, we have explored in this review, the current and future potential capabilities of monoclonal antibodies with respect to diagnosis and treatment of breast cancer. DATA AVAILABILITY: Not applicable.

Carbon-Based Nanocatalysts (CnCs) for Biomass Valorization and Hazardous Organics Remediation.

The continuous increase of the demand in merchandise and fuels augments the need of modern approaches for the mass-production of renewable chemicals derived from abundant feedstocks, like biomass, as well as for the water and soil remediation pollution resulting from the anthropogenic discharge of organic compounds. Towards these directions and within the concept of circular (bio)economy, the development of efficient and sustainable catalytic processes is of paramount importance. Within this context, the design of novel catalysts play a key role, with carbon-based nanocatalysts (CnCs) representing one of the most promising class of materials. In this review, a wide range of CnCs utilized for biomass valorization towards valuable chemicals production, and for environmental remediation applications are summarized and discussed. Emphasis is given in particular on the catalytic production of 5-hydroxymethylfurfural (5-HMF) from cellulose or starch-rich food waste, the hydrogenolysis of lignin towards high bio-oil yields enriched predominately in alkyl and oxygenated phenolic monomers, the photocatalytic, sonocatalytic or sonophotocatalytic selective partial oxidation of 5-HMF to 2,5-diformylfuran (DFF) and the decomposition of organic pollutants in aqueous matrixes. The carbonaceous materials were utilized as stand-alone catalysts or as supports of (nano)metals are various types of activated micro/mesoporous carbons, graphene/graphite and the chemically modified counterparts like graphite oxide and reduced graphite oxide, carbon nanotubes, carbon quantum dots, graphitic carbon nitride, and fullerenes.

Fire Propagation Behavior of Some Biobased Furanic Compounds with a Focus on the Polymer PEF.

Avantium is in the process of building a flagship plant for the production of furandicarboxylic acid (FDCA) and the derived polyester polyethylene furanoate (PEF) using their YXY process. Because of the status of this development of monomer production, next to storage and shipping, polymer production, application development, and polymer recycling, the understanding of the safety aspects of the YXY process is key for a successful deployment of the technology. In this paper, the focus is on fire propagation-related issues for both monomeric furanic compounds and for the polymer PEF and results are compared with relevant reference materials. The current assessment addresses the fire initiation and propagation behavior of FDCA and PEF for the very first time. From the fire safety viewpoint, it can be concluded that of the furanics tested, FDCA has a better safety margin both in terms of a lower thermal and chemical threat, as fires resulting from FDCA are not easily shifting toward underventilated fire scenarios. The obtained results with the PEF polymer are useful in understanding the nature and behavior of PEF under real fire conditions. PEF seems slightly better in terms of the total energy released from the combustion process than the bulk polyester PET. In addition, PEF fires result in lesser CO and soot yields compared to PET, which is proof for a better completeness of combustion.

Evaluation of the Free Radical Scavenging Activities of Ellagic Acid and Ellagic Acid Peracetate by EPR Spectrometry.

The purpose of this study was to examine the free radical scavenging and antioxidant activities of ellagic acid (EA) and ellagic acid peracetate (EAPA) by measuring their reactions with the radicals, 2,2-diphenyl-1-picrylhydrazyl and galvinoxyl using EPR spectroscopy. We have also evaluated the influence of EA and EAPA on the ROS production in L-6 myoblasts and rat liver microsomal lipid peroxidation catalyzed by NADPH. The results obtained clearly indicated that EA has tremendous ability to scavenge free radicals, even at concentration of 1 µM. Interestingly even in the absence of esterase, EAPA, the acetylated product of EA, was also found to be a good scavenger but at a relatively slower rate. Kinetic studies revealed that both EA and EAPA have ability to scavenge free radicals at the concentrations of 1 µM over extended periods of time. In cellular systems, EA and EAPA were found to have similar potentials for the inhibition of ROS production in L-6 myoblasts and NADPH-dependent catalyzed microsomal lipid peroxidation.

DFT, Monte Carlo and molecular dynamics simulations for the prediction of corrosion inhibition efficiency of novel pyrazolylnucleosides on Cu(111) surface in acidic media.

Five novel pyrazolylnucleosides have been evaluated theoretically for their corrosion inhibition efficiency on the Cu(111) surface in acidic media. DFT calculations were carried out to exhibit the intrinsic properties such as lowest unoccupied (ELUMO) and highest occupied (EHOMO) molecular orbital energies, as well as energy gap (∆E), chemical hardness (η), chemical softness (σ), electronegativity (χ), electrophilicity (ω) and nucleophilicity (ε). The theoretical FT-IR spectra were recorded to indicate the presence of the specific bonds in the studied molecules. The surface interactions between the inhibitor molecules and the metal surface were investigated using molecular dynamics simulations and Monte Carlo (MC) simulations. As a result, we have found that the inhibitor pyrazolylnucleosides 5a-e have strong interactions with Cu(111) surface, and therefore have excellent predictive inhibition power against copper corrosion.

Innovative Protocols in the Catalytic Oxidation of 5-Hydroxymethylfurfural.

5-Hydroxymethylfurfural (HMF) has been identified as one of the most promising biomass-based multi-purpose platform molecules. Innovative protocols, namely electrocatalysis, photocatalysis, and microwave (MW)-assisted chemistry, as well as continuous-flow systems, add a new dimension and another promising toolbox for the oxidation of HMF in recent years. This Minireview deals with recent progress in the catalytic oxidation of HMF to 2,5-furandicarboxylic acid (FDCA) and other intermediates using noble, non-noble, and metal-free systems deploying emerging protocols. Selective HMF downstream oxidation products could be obtained not only via common catalyst modifications, namely nature of the metal, preparative method, and the property of deployed support, but also by using innovative processes.

A review on high catalytic efficiency of solid acid catalysts for lignin valorization.

It is imminent to develop renewable resources to replace fossil-derived energies as fossil resources are on the brink of exhaustion. Lignin is one of the major components of lignocellulosic biomass, which is a natural amorphous three-dimensional polymer with abundant C-O bonds and aromatic structure. Hence, valorization of lignin into high value-added liquid fuels and chemicals is regarded as a promising strategy to mitigate fossil resource shortages. Solid acid catalysts are extensively studied due to environmentally friendly in terms of the ease of separation, recovery and reduced amount of wastes. Hence, this review focuses on summarizing the recent progress of catalytic valorization of lignin over different kinds of solid acid catalysts including zeolites, heteropolyacids, metal oxides, amorphous SiO2-Al2O3, metal phosphates, and Lewis acid. Based on reviewing of current progress of lignin conversion, the challenges and future prospects are emphasized.

Synthetic, Structural, and Anticancer Activity Evaluation Studies on Novel Pyrazolylnucleosides.

The synthesis of novel pyrazolylnucleosides 3a-e, 4a-e, 5a-e, and 6a-e are described. The structures of the regioisomers were elucidated by using extensive NMR studies. The pyrazolylnucleosides 5a-e and 6a-e were screened for anticancer activities on sixty human tumor cell lines. The compound 6e showed good activity against 39 cancer cell lines. In particular, it showed significant inhibition against the lung cancer cell line Hop-92 (GI50 9.3 µM) and breast cancer cell line HS 578T (GI50 3.0 µM).

A Novel Strategy for Selective O-Methylation of Glycerol in Subcritical Methanol.

A new regioselective approach has been elaborated for the selective conversion of bio-based glycerol into the monomethyl derivative using sub/supercritical methanol. The reaction was realized in a batch process using three reactive components, namely, glycerol, methanol, and potassium carbonate to selectively produce the 3-methoxypropan-1,2-diol in mild yields; the mechanism of the O-methylation has been delineated using labeled methanol and GC-MS experiments.

One-Pot FDCA Diester Synthesis from Mucic Acid and Their Solvent-Free Regioselective Polytransesterification for Production of Glycerol-Based Furanic Polyesters.

A one pot-two step procedure for the synthesis of diethyl furan-2,5-dicarboxylate (DEFDC) starting from mucic acid without isolation of the intermediate furan dicarboxylic acid (FDCA) was studied. Then, the production of three different kinds of furan-based polyesters- polyethylene-2,5-furan dicarboxylate (PEF), polyhydropropyl-2,5-furan dicarboxylate(PHPF) and polydiglycerol-2,5-furandicarboxylate (PDGF)-was realized through a Co(Ac)2·4H2O catalyzed polytransesterification performed at 160 °C between DEFDC and a defined diol furan-based prepolymer or pure diglycerol. In parallel to polymerization process, an unattended regioselective 1-OH acylation of glycerol by direct microwave-heated FDCA diester transesterification led to the formation of a symmetric prepolymer ready for further polymerization and clearly identified by 2D NMR sequences. Furthermore, the synthesis of a more soluble and hydrophilic diglycerol-based furanic polyester was also achieved. The resulting biobased polymers were characterized by NMR, FT-IR spectroscopy, DSC, TGA and XRD. The morphologies of the resulted polymers were observed by FE-SEM and the purity of the material by EDX.

Development of Sulfonic-Acid-Functionalized Mesoporous Materials: Synthesis and Catalytic Applications.

Sulfonic acid based mesostructures (SAMs) have been developed in recent years and have important catalytic applications. The primary applications of these materials are in various organic synthesis reactions, such as multicomponent reactions, carbon-carbon bond couplings, protection reactions, and Fries and Beckman rearrangements. This review aims to provide an overview of the recent developments in the field of SAMs with a particular emphasis on the reaction scope and advantages of heterogeneous solid acid catalysts.

Recent Advances in the Microwave-Assisted Production of Hydroxymethylfurfural by Hydrolysis of Cellulose Derivatives-A Review.

The concepts of sustainable development, bioeconomy, and circular economy are being increasingly applied for the synthesis of molecules of industrial interest. Among these molecules, hydroxymethylfurfural as a platform molecule is the subject of various research approaches to improve its synthesis and productivity, and extend its potential uses. Accordingly, this review paper aims essentially at outlining recent breakthroughs obtained in the field of hydroxymethylfurfural production from sugars and polysaccharide feedstocks under microwave-assisted technology. The review discusses advances obtained via microwave activation in major production pathways recently explored, split into the following categories: (i) use of various homogeneous catalysts like mineral or organic acids, metal salts, or ionic liquids; (ii) feedstock dehydration making use of various solid acid catalysts; and (iii) non-catalytic routes.

Hydrolysis of Hemicellulose and Derivatives-A Review of Recent Advances in the Production of Furfural.

Biobased production of furfural has been known for decades. Nevertheless, bioeconomy and circular economy concepts is much more recent and has motivated a regain of interest of dedicated research to improve production modes and expand potential uses. Accordingly, this review paper aims essentially at outlining recent breakthroughs obtained in the field of furfural production from sugars and polysaccharides feedstocks. The review discusses advances obtained in major production pathways recently explored splitting in the following categories: (i) non-catalytic routes like use of critical solvents or hot water pretreatment, (ii) use of various homogeneous catalysts like mineral or organic acids, metal salts or ionic liquids, (iii) feedstock dehydration making use of various solid acid catalysts; (iv) feedstock dehydration making use of supported catalysts, (v) other heterogeneous catalytic routes. The paper also briefly overviews current understanding of furfural chemical synthesis and its underpinning mechanism as well as safety issues pertaining to the substance. Eventually, some remaining research topics are put in perspective for further optimization of biobased furfural production.