Low Molecular Weight Products Research Articles

Effect of increased surface hydrophobicity via drug conjugation on the clearance of inhaled PEGylated polylysine dendrimers.

PEGylated polylysine dendrimers are attractive and well tolerated inhalable drug delivery platforms that have the potential to control the release, absorption kinetics and lung retention time of conjugated drugs. The clinical application of these systems though, would likely require partial substitution of surface PEG groups with drug molecules that are anticipated to alter their lung clearance kinetics and clearance pathways. In the current study, we therefore evaluated the impact of increased surface hydrophobicity via substitution of 50% surface PEG groups with a model hydrophobic drug (α-carboxyl OtButylated methotrexate) on the lung clearance of a Generation 5 PEGylated polylysine dendrimer in rats. PEG substitution with OtBu-methotrexate accelerated lung clearance of the dendrimer by increasing polylysine scaffold catabolism, improving systemic absorption of the intact dendrimer and low molecular weight products of scaffold catabolism, and enhancing mucociliary clearance. These results suggest that the conjugation of hydrophobic drug on the surface of a PEGylated dendrimer is likely to accelerate lung clearance when compared to a fully PEGylated dendrimer.

Sustainable Electrochemical Depolymerization of Lignin in Reusable Ionic Liquids

Lignin’s aromatic building blocks provide a chemical resource that is, in theory, ideal for substitution of aromatic petrochemicals. Moreover, degradation and valorization of lignin has the potential to generate many high-value chemicals for technical applications. In this study, electrochemical degradation of alkali and Organosolv lignin was performed using the ionic liquids 1-ethyl-3-methylimidazolium trifluoromethanesulfonate and triethylammonium methanesulfonate. The extensive degradation of the investigated lignins with simultaneous almost full recovery of the electrolyte materials provided a sustainable alternative to more common lignin degradation processes. We demonstrate here that both the presence (and the absence) of water during electrolysis and proton transport reactions had significant impact on the degradation efficiency. Hydrogen peroxide radical formation promoted certain electrochemical mechanisms in electrolyte systems “contaminated” with water and increased yields of low molecular weight products significantly. The proposed mechanisms were tentatively confirmed by determining product distributions using a combination of liquid chromatography-mass spectrometry and gas-chromatography-mass spectrometry, allowing measurement of both polar versus non-polar as well as volatile versus non-volatile components in the mixtures.

Optimization-based framework for resin selection strategies in biopharmaceutical purification process development.

This work addresses rapid resin selection for integrated chromatographic separations when conducted as part of a high‐throughput screening exercise during the early stages of purification process development. An optimization‐based decision support framework is proposed to process the data generated from microscale experiments to identify the best resins to maximize key performance metrics for a biopharmaceutical manufacturing process, such as yield and purity. A multiobjective mixed integer nonlinear programming model is developed and solved using the ε‐constraint method. Dinkelbach's algorithm is used to solve the resulting mixed integer linear fractional programming model. The proposed framework is successfully applied to an industrial case study of a process to purify recombinant Fc Fusion protein from low molecular weight and high molecular weight product related impurities, involving two chromatographic steps with eight and three candidate resins for each step, respectively. The computational results show the advantage of the proposed framework in terms of computational efficiency and flexibility. © 2017 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers Biotechnol. Prog., 33:1116–1126, 2017

Intact cell MALDI-TOF mass spectrometry on single bovine oocyte and follicular cells combined with top-down proteomics: A novel approach to characterise markers of oocyte maturation

Intact cell MALDI-TOF mass spectrometry (ICM-MS) was adapted to bovine follicular cells from individual ovarian follicles to obtain the protein/peptide signatures (<17kDa) of single oocytes, cumulus cells (CC) and granulosa cells (GC), which shared a total of 439 peaks. By comparing the ICM-MS profiles of single oocytes and CC before and after in vitro maturation (IVM), 71 different peaks were characterised, and their relative abundance was found to vary depending on the stage of oocyte meiotic maturation. To identify these endogenous biomolecules, top-down workflow using high resolution MS/MS (TD HR-MS) was performed on the protein extracts from oocytes, CC and GC. The TD HR-MS proteomic approach allowed for: (1) identification of 386 peptide/proteoforms encoded by 194 genes; and (2) characterisation of proteolysis products likely resulting from the action of kallikreins and caspases. In total, 136 peaks observed by ICM-MS were annotated by TD HR-MS (ProteomeXchange PXD004892). Among these, 16 markers of maturation were identified, including IGF2 binding protein 3 and hemoglobin B in the oocyte, thymosins beta-4 and beta-10, histone H2B and ubiquitin in CC. The combination of ICM-MS and TD HR-MS proved to be a suitable strategy to identify non-invasive markers of oocyte quality using limited biological samples. Biological significanceIntact cell MALDI-TOF mass spectrometry on single oocytes and their surrounding cumulus cells, coupled to an optimised top-down HR-MS proteomic approach on ovarian follicular cells, was used to identify specific markers of oocyte meiotic maturation represented by whole low molecular weight proteins or products of degradation by specific proteases.

Chemoselective Methylation of Phenolic Hydroxyl Group Prevents Quinone Methide Formation and Repolymerization During Lignin Depolymerization

Chemoselective blocking of the phenolic hydroxyl (Ar–OH) group by methylation was found to suppress secondary repolymerization and charring during lignin depolymerization. Methylation of Ar–OH prevents formation of reactive quinone methide intermediates, which are partly responsible for undesirable secondary repolymerization reactions. Instead, this structurally modified lignin produces more relatively low molecular weight products from lignin depolymerization compared to unmodified lignin. This result demonstrates that structural modification of lignin is desirable for production of low molecular weight phenolic products. This approach could be directed toward alteration of natural lignification processes to produce biomass that is more amenable to chemical depolymerization.

Formation of low molecular weight oligomers from chitin and chitosan stimulated by plasma-assisted processes

The controlled degradation of solid powders of chitin and chitosan stimulated by electron-beam plasma (EBP) was experimentally studied. Crab shell chitin and chitosan were used as original substances. The non-equilibrium low temperature EBP was generated by injecting an electron beam into a gaseous medium. Chitooligosaccharides with Mw=800–2000Da and polydispersion 1.5–2.5 were formed due to the EBP-treatment of chitin and chitosan. The β-1,4 glycosidic bounds in original polymers degrade under the action of active oxygen species produced in the EBP. Low molecular weight products of chitosan inhibited the growth of various yeast-like and filamentous fungi at minimum inhibitory concentration 500mcg/ml. By optimizing the treatment conditions and using special techniques of reaction volume formation the 95% yield of chitooligosaccharides was obtained after 2min whereas the conventional chemical hydrolysis usually takes several days. The EBP-stimulated hydrolysis is promising for effective polysaccharides degradation and can be competitive with traditional technologies.

The effect of Transfer Factor as Immunotherapy comparing with the effect of BCG in Mice challenged with Mycobacterium tuberculosis

Background: Transfer Factor (TF) is an immune modulator which stimulates the cellular arm of the immune system (killer lymphocytes), activates immune cytokine synthesis and regulates immune function (Lawrence, 1955).TF is very effective in those diseases in which CMI plays a relevant role in protection and control of the disease, such as intracellular bacterial diseases (tuberculosis). ( Estrada Parra, et al1955). TF are low molecular weight products from immune cells that are able to transmit the ability to express delayed-type hypersensitivity (DTH) and cell mediated immunity (CMI) from sensitized donors to non immune recipients (Kirkpatrick, 2000). Objectives: The aim of this experimental study is to determine the protective efficacy of transfer factor (TF) as immunotherapy for mice in comparison to BCG. Materials and methods: A total number of 102 mice were examined for their immunopotency and protective efficacy of Transfer factor (TF) comparing to the protective efficacy of BCG single and second repeated dose against challenge dose of M. tuberculosis (107 CFU) . A number of 20 mice were immunize with the attenuated strain of M. bovis, Bacillus Calmette-Guerin (BCG). After 21 days of BCG spleens of 10 tuberculous mice were removed aseptically for the preparation of TF. To evaluate the effect of TF 3 groups of inbred BALB/c male mice were injected with TF and challenged with virulent M. tuberculosis, followed by another 3 groups of inbred BALB/c male mice which were immunized with BCG single and second repeated dose. All mice with BCG and TF were tested for tuberculin skin test (TST) so as to determine susceptibility and resistance against tuberculosis, susceptible groups of mice were challenged with virulent M. tuberculosis. Followed by study of humoral response by immunization of a group of mice with immune serum and challenged with M. tuberculosis H37Rv strain. Followed by an experiment of group A and B for the susceptibility and resistance of the strains of mice. A group of dead mice For histological study of the infected lungs were examined. Results:After three weeks of observations the mice of experiment(1) were tested for tuberculin skin test and the results were positive. Effectiveness determination of TF as protective efficacy was (83.3%). while effectiveness determination and protective efficacy of BCG first dose and boosting dose were (50%) and (70%) respectively. Humoral immunity response against M. tuberculosis showed negative reaction hence mortality rate was 100%, group B mice were resistant for BCG (Swiss white strain) and the results of histological study of the infected lungs showed lung bacilli that was M. tuberculosis. Conclusions: The results indicated that administration of murine transfer factor (mTF) extracted and prepared from spleen of animal model (mice) as immunotherapy for challenged mice of MTB (H37Rv) showed a better results enhanced immune response in respect to delayed type hypersensitivity , survival rate and mortality rate suggesting that efficacy of mTF as immunotherapy for tuberculosis. Repeat dose of BCG enhanced immune response in respect to delayed type hypersensitivity , survival rate (70%) and mortality rate (30%), suggesting that efficacy of BCG vaccine may improve and give better results if booster doses are given.

Solid base catalyzed depolymerization of lignin into low molecular weight products

We report the depolymerization of high molecular weight lignin (60 000 Da) over various recyclable solid base catalysts at 250 °C over 1 h.

Reduction in cardiometabolic risk factors by a multifunctional diet is mediated via several branches of metabolism as evidenced by nontargeted metabolite profiling approach.

Multifunctional diet (MFD), a diet based on multiple functional concepts and ingredients with anti-inflammatory activity, was previously shown to improve different cardiometabolic risk-associated markers in healthy subjects. Here, we assessed the impact of MFD on plasma metabolome and explored associations of the differential metabolites with clinical parameters, searching for metabolic determinants related to the effects of MFD. Forty-four overweight healthy volunteers completed a randomized crossover intervention comparing MFD with a control diet devoid of the active components of MFD. Fasting plasma samples were analyzed with nontargeted metabolite profiling at baseline and at the end (4 wk) of each diet period by LC coupled to quadrupole-TOF-MS system, revealing a vast impact of MFD on metabolic homeostasis. Main metabolite classes affected included acylcarnitines, furan fatty acids, phospholipids (plasmalogens, phosphatidylcholines, phosphatidylethanolamines), and various low-molecular weight products from the bioactivity of gut microbiota. Circulating levels of several of these metabolites correlated with changes in clinical blood lipid biomarkers. The metabolomics approach revealed that consumption of MFD affected different areas of metabolism, highlighting the impact of a healthy diet on plasma metabolome. This seems linked to reduced cardiometabolic risk and provides mechanistic insight into the effects of MFD.

СИНТЕЗ НАНОДИСПЕРСНЫХ ЙОДСОДЕРЖАЩИХ КОМПОЗИТОВ

The purpose of research is to develop techniques for chemical implementation of the obtained low molecular weight products with covalently bound iodine in the biodegradable matrix (glycyrrhizic acid) with obtaining nanosized composites, capable of metered cleavage of iodine in vivo. One of the vital trace elements is iodine. Adding iodine to food components is an advanced technology and it promotes replenishment of iodine deficiency in human organism. The most interesting compounds wherethe inorganic iodine are chemically bound to the organic matrix. The processes of formation of the complex &amp;#34;o-iodobenzoic acid-β-glycyrrhizic acid&amp;#34; and encapsulation mechanisms of 5-iodo-6-metiluratsila in nanoscale biodegradable matrix -β-glycyrrhizic acid by using physical and chemical methods of analysis – IR, UV and NMR spectroscopy. The evaluationof nano-sized ofsynthesized iodinebioorganic complexes by laser nanostructured analysis is carried out. The processes of deiodination o-iodobenzoic acid in vivo by high-performance liquid chromatography is examed. The conducted research showsthe bioavailability of synthesized nanostructured iodine organic-mineral complex.

Baricitinib for the treatment of rheumatoid arthritis

ABSTRACTIntroduction: Rheumatoid arthritis (RA) is characterized by systemic synovitis causing joint destruction. With the development of biological disease-modifying anti-rheumatic drugs (bDMARDs) and combination of conventional DMARDs, clinical remission is perceived as an appropriate and realistic goal in many patients. However, bDMARDs require intravenous or subcutaneous injection and some patients fail to respond to bDMARDs or lose their primary response. Under the circumstances, targeted synthetic DMARDs (tsDMARDs), which are orally available low-molecular weight products, have been emerging. Five phase 3 trials of Baricitinib, a JAK1 and JAK2 inhibitor, have been performed and showed high clinical efficacy in patients with active RA and naïve to sDMARDs or an inadequate response to sDMARDs, MTX or bDMARDs. There was a favorable response for clinical and functional parameters in studies with placebo, MTX and adalimumab as comparator. It is also reported that safety was tolerable within the limited study period.Areas covered: We here review the recent progress in the development of baricitinib and its potential for the treatment of RA.Expert commentary: Although baricitinib is only one of the highly effective DMARDs that has a new mode of action, it will bring new concepts for rheumatology in the future.

Problems in the evaluation of polyvinylpyrrolidone (PVP) elution from polysulfone membrane dialyzers sterilized by gamma-ray irradiation

Adverse reactions, such as anaphylactoid shock, have been reported to occur frequently with the use of polysulfone (PSf) membrane dialyzers. Polyvinylpyrrolidone (PVP) elution from the membrane may be a key factor in these reactions. In this paper, we discuss the problems in the evaluation of PVP elution from PSf membrane dialyzers sterilized by gamma-ray irradiation. PVP concentrations in the filling solutions in some wet-type PSf membrane dialyzers are measured by Müller’s method as a standard measurement method. The PVP concentrations in autoclave (AC)-sterilized dialyzers were one order of magnitude higher than those in the solutions in dialyzers sterilized by gamma-ray irradiation. Because it is difficult to determine the PVP concentrations in the filling solutions sterilized by gamma-ray irradiation by Müller’s method, single-fractionated-component PVP solutions with fractionated components of PVP (K90 or K30) were prepared and the PVP concentrations of the solutions before and after gamma-ray irradiation were determined. The results indicated that the PVP concentrations in the solutions could be determined by Müller’s method before irradiation, whereas PVP was undetectable in the solution after irradiation. For single-fractionated-component PVP solutions with K90 and K30, the changes in the structure of PVP before and after gamma-ray irradiation were analyzed by high-performance liquid chromatography (HPLC). The single-fractionated-component PVP solutions with K90 and K30 had a broad peak at retention times of 15 and 19 min, respectively, prior to the gamma-ray irradiation, whereas both solutions showed a similar sharp peak at a retention time of 23 min after the irradiation. Based on these results, it is surmised that PVP is degraded by irradiation to yield PVP degradation products of low molecular weight. Furthermore, nuclear magnetic resonance (NMR) spectroscopy for PVP K90 solution was performed to confirm the signals from the vinylpyrrolidone (VP) skeletal structures. Signals from the VP skeletal structures were detected before the gamma-ray irradiation but disappeared after the irradiation. Thus, it appears that the degradation products of PVP without VP skeletal structures cannot be detected by Müller’s method. The measurement of PVP concentrations by Müller’s method is inappropriate for the evaluation of PVP elution from PSf membrane dialyzers sterilized by gamma-ray irradiation.

Laser ablation coupled with DAPNe-NSI-MS applied to redacted documents

Laser ablation has been applied to redacted documents, where the text has been concealed by other ink. This technique strips the redacting ink revealing the text that was once redacted. Once removed, a nanomanipulation technique is used to extract the ink of the underlying text where mass spectrometry is then implemented to analyze its ink chemistry. In order to facilitate microscopy with direct analyte-probed nanoextraction coupled to nanospray ionization mass spectrometry (DAPNe-NSI-MS), laser ablation must be executed prior to ink extraction. Laser ablation has a nondestructive approach of stripping the ink used to redact the document. Not only does this reveal the text, it clears an area for DAPNe to directly extract ink, in miniscule amounts, from the document without inducing destruction. The redacting ink was concluded to affect the aging process of the concealed handwritten ink more than the printed text. The redacted handwritten sample obtained higher relative peak area (%) values than the control samples (text that was not redacted) and the control for the printed text produced higher amounts of low molecular weight products than the sample. Implementing laser ablation on these samples could also affect the chemical properties of the underlying ink due to the additional UV radiation and plasma heating. Results indicate by using laser ablation to remove the redacting ink, the relative peak area of the underlying ink deviates by 1.25%. The thermal degradation of binding agents such as polymethylene, polyethylene glycol, and diethylene glycol was monitored by calculating the relative peak area for five days which, in turn, tracks the oxidation process. The relative peak area values were also used to determine the chemical kinetics of polyethylene glycol, where degradation and polymerization occur.

Pyrolysis of Polyacrylonitrile/Technical Hydrolytic Lignin Composites

&lt;p&gt;One important problem is utilization of technical hydrolytic lignin (the waste formed paper-and-pulp and hydrolysis industry). For a practical implementation, the essential task of transforming insoluble hydrolytic lignin into low molecular weight products with high degree of functionalization should be performed. In prospect, these products can serve as raw materials for synthesis of various organic compounds demanded in chemical industry. Among other things, activation and fragmentation of hydrolytic lignin yields low molecular weight compounds which may be used for modifying synthetic polymers (polymer-analogous transformations). In the present work, the search for the optimal solvents (activators) for technical hydrolytic lignin has been conducted; the dimethyl sulfoxide/water binary mixture proved to be the best solvent. Methods of thermal analysis (thermogravimetric analysis, TGA; differential thermal analysis, DTA; differential scanning calorimetry, DSC; thermal volumetric analysis, TVA) combined with pyrolysis-gas chromatography/mass spectrometry (GC-MS) were used to determine the grades of technical hydrolytic lignin most suitable for activation and fragmentation. The necessary conditions for thermal treatment of lignin samples and concentrations of initial compounds (lignin and polyacrylonitrile, PAN) in the binary solvent mixture (dimethyl sulfoxide/water) facilitating maximum THL fragmentation and its successful interaction with PAN were found. When using the dimethylsulfoxide-water binary mixture (70:30 mass ratio) as a solvent, homogeneous forming solution of initial components (THL-PAN) was prepared. With the use of syringe method, form-stable fibers with a maximum lignin content of 80% and strength of about 50 MPa were obtained. Analytical pyrolysis of composites (products of THL-PAN interaction in the binary solvent) allowed us to suggest a mechanism for THL fragmentation involving the binary solvent.&lt;/p&gt;

Stabilization of Empty Fruit Bunch derived Bio-oil using Solvents

The intention of this research was to select the ideal condition for accelerated aging of bio-oil and the consequences of additive in stabilizing the bio-oil. The bio-oil was produced from the catalytic pyrolysis of empty fruit bunch. The optimum reaction conditions applied to obtain the utmost bio-oil yield were 5 wt% of H-Y catalyst at reaction temperature of 500 °C and nitrogen flow rate of 100 ml/min. A 10 wt% of solvents including acetone, ethanol, and ethyl acetate were used to study the bio-oil’s stability. All the test samples were subjected to accelerated aging at temperature of 80 °C for 7 days. The properties of samples used as the indicator of aging were viscosity and water content. The effectiveness of solvents increased in the following order: acetone, ethyl acetate, and 95 vol% ethanol. Based on the result of Gas Chromatography-Mass Spectrometry (GC-MS), it could impede the chain of polymerization by converting the active units in the oligomer chain to inactive units. The solvent reacted to form low molecular weight products which resulted in lower viscosity and lessen the water content in bio-oil. Addition of 95 vol% ethanol also inhibited phase separation.

From top-down to bottom-up: Time-dependent monitoring of proteolytic protein degradation by LC-MS.

The understanding of proteolytic processes includes manifold aspects, ranging from the characterization of proteases and their corresponding substrates to the localization of cleavage sites. The analysis of protease-catalyzed reactions at a single time-point in many cases excludes the identification of intermediate cleavage products of potential biological function. To overcome this problem, proteolysis has to be monitored over time. For that purpose, we established a straight-forward two-step approach. First, Tricine-SDS-PAGE separation of the proteolytic products is applied to survey the proteolytic reaction. In the second step, the reaction mixture is analyzed by an LC-MS set-up. An optimized chromatographic separation coupled to electrospray Orbitrap mass spectrometry allowed the simultaneous monitoring of intact substrates, intermediates and cleavage products of lower molecular weight. The applicability of the strategy was shown on the example of the gastric protease pepsin and its physiologically relevant substrate hen egg white lysozyme, one of the major egg allergens. While lysozyme-derived cysteine-free peptides were cleaved comparatively fast, disulfide bonds protected connected peptides from rapid peptic proteolysis. Two previously identified potential IgE-binding motifs were observed as disulfide-linked cleavage products. In summary, the presented approach is not only ideally suited for the simulation of gastro-intestinal digestion, which is of high interest in food research, but can be transferred to any protease-substrate pair of interest. Furthermore the strategy can be exploited to deduce the effect of post-translational modifications on proteolysis.

Morin and Its Role in Chronic Diseases.

Chronic diseases can be referred to the long-term medical conditions which are mostly progressive in nature, i.e., it deteriorates over time. Diabetes, arthritis, heart disease, stroke, cancer, and chronic respiratory problems (e.g., COPD) are not a few examples of chronic diseases and chronic diseases are the leading causes of death and disability all over the world. Chronic diseases and conditions are among the most common, costly, and preventable of all health problems. Affordable cost, presence mostly in the consumables, and minimal side effects make the naturally occurring compounds interesting and attractive for pharmacological study in recent years. Plants produce diverse types of low molecular weight products mainly for the defense purpose. Among them, the group of secondary metabolites related to a polyphenolic group has been named flavonoids and are of great interest due to their incredible pharmacological properties. In these regard, due to its potent anti-inflammatory, anti-apoptotic and many important pharmacological properties (relevant to chronic diseases, e.g., urate transporter inhibitor related to gout, modulator of immunosystem related to chronic hypersensitivity, etc.), morin [morin hydrate:2-(2,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-1-benzopy ran-4-one; 3,5,7,20,40 pentahydroxyflavone], widely found among the Moraceae family, considered as one of the most important key bioflavonols. However, little is known about the molecular mechanisms of its action on such conditions. In this chapter, we have summarized most of the findings, if not all, available till date.

Iron-catalyzed depolymerizations of end-of-life silicones with fatty alcohols

During the last decades, polymers became one of the major materials in our society and a future without polymers is hardly imaginable. However, as negative issue of this success enormous amount of end-of-life materials are accumulated, which are mainly treated by landfill storage, thermal recycling or down-cycling. On the other hand, feedstock recycling can be an interesting option to convert end-of-life polymers to highquality polymers, via depolymerization reactions to low-molecular weight building blocks and subsequent transformation via polymerization reactions. In this regard, we present herein the depolymerization of polysiloxanes (silicones) applying fatty alcohols as depolymerization reagents. In more detail, in the presence of catalytic amounts of simple iron salts, low-molecular weight products with the motif R(OSiMe2)mOR (R = alkyl,m = 1–2) were attained. Remarkably, the reaction of R(OSiMe2)mOR with water showed the formation of new cyclic siloxanes, which are useful starting materials for long-chain silicones, and the corresponding fatty alcohol as side product, which can be directly reused in subsequent depolymerization reactions. Importantly, a recycling of the silicones and a straightforward recycling of the depolymerization reagent are feasible.

Iron-catalyzed depolymerizations of end-of-life silicones with fatty alcohols

Abstract During the last decades, polymers became one of the major materials in our society and a future without polymers is hardly imaginable. However, as negative issue of this success enormous amount of end-of-life materials are accumulated, which are mainly treated by landfill storage, thermal recycling or down-cycling. On the other hand, feedstock recycling can be an interesting option to convert end-of-life polymers to high quality polymers, via depolymerization reactions to low-molecular weight building blocks and subsequent transformation via polymerization reactions. In this regard, we present herein the depolymerization of polysiloxanes (silicones) applying fatty alcohols as depolymerization reagents. In more detail, in the presence of catalytic amounts of simple iron salts, low-molecular weight products with the motif R(OSiMe 2 ) m OR (R = alkyl, m = 1–2) were attained. Remarkably, the reaction of R(OSiMe 2 ) m OR with water showed the formation of new cyclic siloxanes, which are useful starting materials for long-chain silicones, and the corresponding fatty alcohol as side product, which can be directly reused in subsequent depolymerization reactions. Importantly, a recycling of the silicones and a straightforward recycling of the depolymerization reagent are feasible.

Hydrothermal microwave valorization of eucalyptus using acidic ionic liquid as catalyst toward a green biorefinery scenario

The application of the acidic ionic liquid (IL), 1-butyl-3-methylimidazolium hydrogensulfate ([bmim]HSO4), as a catalyst in the hydrothermal microwave treatment (HMT) and green upgradation of eucalyptus biomass has been investigated. The process was carried out in a microwave reactor system at different temperatures (140–200°C) and evaluated for severities. The xylooligosaccharides (XOS, refers to a DP of 2–6) yield up to 5.04% (w/w) of the initial biomass and 26.72% (w/w) of xylan were achieved. Higher temperature resulted in lower molecular weight product, and enhanced the concentration of monosaccharides and byproducts. The morphology and structure of the solid residues were performed using an array of techniques, such as SEM, XRD, FTIR, BET surface area, and CP/MAS 13C NMR, by which the increase of crystallinity, the destruction of surface structure, and the changes in functional groups and compositions were studied after the pretreatment, thus significantly enhancing the enzymatic hydrolysis.