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Both sugars and lipids are important biomolecular building blocks with exceptional conformational flexibility and adaptability to their environment. Glycolipids bring together these two molecular components in the same assembly and combine the complexity of their conformational landscapes. In the present study, we have used selective double resonance vibrational spectroscopy, in combination with a computational approach, to explore the conformational preferences of two glycolipid models (3-0-acyl catechol and guaiacol α-D-glucopyranosides), either fully isolated in the gas phase or controlled interaction with a single water molecule. We could identify the preferred conformation and structures of the isolated and micro-hydrated species and evidence of the presence of a strong water pocket, which may influence the conformational flexibility of such systems, even in less controlled environments. [ABSTRACT FROM AUTHOR]

Selective hydrogenation of guaiacol to 2-methoxycyclohexanone was investigated with various Pd catalysts. This reaction is much more difficult than the hydrogenation of phenol to cyclohexanone, namely in terms of the low reactivity of guaiacol and the reduced selectivity of 2-methoxycyclohexanone due to the demethoxylation reaction. Pd/TiO2 catalysts were found to be superior to other supported Pd catalysts in terms of activity and selectivity to 2-methoxycyclohexanone. The Pd dispersion did not affect the selectivity of Pd/TiO2 catalysts. Meanwhile, the increase of Pd dispersion decreased the turnover frequency, and the optimum Pd dispersion was about 25%. The presence of residual chloride ions had a negative effect on the selectivity to 2-methoxycyclohexanone. The optimal Pd/TiO2 catalyst gave 65% yield of 2-methoxycyclohexanone. The catalyst was reusable after washing with toluene solvent to extract residual organic species from the catalyst surface. The catalyst was capable of hydrogenating various phenolic compounds, namely methoxyphenols, into the corresponding cyclohexanone derivatives. [ABSTRACT FROM AUTHOR]

The sustainable development of energy has always been a concern. Upgrading biomass catalysis into hydrocarbon liquid fuels is one of the effective methods. In order to upgrade biomass derivative guaiacol by Hydrodeoxygenation (HDO) catalysis, this article report a three‐dimensional honeycomb structure biochar loaded with Ni nanoparticles and phosphomolybdic acid demonstrating excellent catalytic performance in a short period of time. This is due to the porous structure of biochar, which allows Ni metal nanoparticles to be highly uniformly dispersed on the support, which enhances the catalytic hydrogenation of guaiacol in terms of both rate and efficiency. Furthermore, it was observed that the added phosphomolybdic acid dissolved within the temperature range of 78–90 °C, functioning as a homogeneous catalyst in the process. This proves advantageous, as the phosphomolybdic acid becomes accessible at any location within the porous Ni/C catalyst. The detailed characterization data revealed that the carbon support prepared in this study has a high specific surface area of up to 1375.61 m2/g. Additionally, the phosphomolybdic acid exhibited rich acidity, with Brønsted and Lewis acid contents of 2.55 μmol/g and 21.45 μmol/g, respectively. Reaction data demonstrated that at 240 °C for 180 min, 100 % conversion and 97.9 % cyclohexane selectivity were achieved. This study introduces a bifunctional catalyst with an unique catalyst's structure, facilitating a heterogeneous‐homogeneous catalytic reaction and delivering an efficient catalytic effect. [ABSTRACT FROM AUTHOR]

The primary aim of this study is to break down the methoxy (-OCH3) and hydroxyl(-OH) oxygenates present in lignin, a component of biomass. This degradation was performed on a lignin-derived model compound, guaiacol, using a highly effective Ni-loaded SBA-15 catalyst. SBA-15 was synthesized via a hydrothermal method, and varying amounts of NiO (5, 10, 15, 20, 25 wt%) were incorporated into SBA-15 through wet impregnation. The catalysts were characterized by using techniques such as XRD, DRS-UV, FT-IR, TPR, BET, SEM, and HR-TEM. Their catalytic performance was evaluated through the hydrodeoxygenation of guaiacol in a vapor phase reactor under controlled atmospheric pressure conditions. Notably, at 200 °C with a hydrogen flow rate of 50 ml/h, the 10 wt% NiO/SBA-15 catalyst demonstrated superior catalytic activity, achieving high guaiacol conversion and aimed product selectivity. [ABSTRACT FROM AUTHOR]

Methyl halides are crucial trace greenhouse gases in the atmosphere, playing a significant role in global climate change and the atmospheric environment. This study investigated the photochemical production of methyl halides in an artificial seawater system using guaiacol as a precursor through laboratory simulation experiments. The influences of various environmental factors, including illumination time, radiation wavebands, illumination intensity, concentrations of guaiacol and halide ions (X−), Fe3+, salinity, dissolved oxygen (DO), and pH value on the photochemical production of methyl halides were examined. We demonstrated that increased illumination intensity and duration promote the photochemical production of methyl halides, with a notable enhancement under UV-B radiation. Guaiacol and halide ions were identified as key precursors, and their high concentrations facilitated the formation of methyl halides. Additionally, different types of halide ions exhibited a competitive relationship in producing methyl halides. The study found that an increase in pH inhibited the photochemical formation of CH3I due to the reaction between OH− and ·CH3. Dissolved oxygen was found to inhibit the photochemical formation of CH3I while promoting the formation of CH3Cl. Conversely, an appropriate concentration of Fe3+ enhanced the photochemical production of methyl halides. Field observations indicated a high photochemical production of methyl halides in the natural waters near Qingdao's coastal area, likely due to the high concentration of dissolved organic matter (DOM), which supports photochemical reactions. Furthermore, the photochemical production of methyl halides in natural seawater was significantly higher than in dark conditions, underscoring the importance of illumination in promoting these photochemical processes in seawater. [ABSTRACT FROM AUTHOR]

Bio‐oil formaldehyde resole (BFR) can be used as adhesive in plywood industry. However, the BFR has a lower thermal stability, and the reason is still unclear. Herein, the reactivities of four representative phenolic compounds in bio‐oil, including two ortho phenols (2‐methylphenol, 2‐methoxyphenol) and two para phenols (4‐methylphenol and 4‐methoxyphenol), as well as the thermal stabilities of the prepared resoles are investigated. The results show that the reactivity of an ortho phenol is higher than that of a para phenol. The resole prepared from a para phenol has a higher thermal stability than that of an ortho phenol. The resole of an ortho phenol decomposes even when heated at the low temperature of 100 °C. The resole of a methylphenol generally has a higher thermal stability than that of a methoxyphenol. Based on the results, the reason for the low reactivity of bio‐oil and the low thermal stability of BFR are speculated. [ABSTRACT FROM AUTHOR]

Gamma-aminobutyric acid (GABA) is considered an important stress metabolite with regulatory functions in plants. Exogenous GABA can enhance the tolerance of different plant species to drought and salt stress. However, its effects on the functioning of stress-protective systems in triticale, an intergeneric wheat-rye hybrid with specific adaptation strategies to abiotic stresses, remain completely understudied. We examined the effects of exogenous GABA (0.5 mM) on the growth, antioxidant, and osmoprotective systems of triticale seedlings (cv. 'Rarytet') under simulated drought (15% PEG 6000), salt stress (100 mM NaCl), or a combination of these two factors. GABA mitigated the growth-inhibitory effects of drought by approximately 15% and salt stress by approximately 23%. However, GABA's most noticeable impact was seen on biomass accumulation under combined stress: it decreased the biomass accumulation inhibition caused by a drought-salt stress combination by 67%; GABA also increased the water content in seedling tissues when subjected to each stressor separately and to the combination of the two. GABA considerably reduced drought- and salt-triggered enhancement of ROS generation and lipid peroxidation. GABA increased the activities of antioxidant enzymes, such as superoxide dismutase, catalase, and guaiacol peroxidase, under physiologically normal conditions under the influence of PEG 6000 or NaCl. Subjected to a drought-salt stress combination, GABA prevented a reduction in the activities of these enzymes. Under normal and stressful conditions, exogenous GABA also modulated the contents of proline, sugars, phenolic compounds, and anthocyanins in the seedlings. We concluded that the stress-protective systems of triticale were highly susceptible to GABA and that it was possible to use GABA to enhance the tolerance of this species to osmotic stresses, especially under a combined impact of drought and salinity. [ABSTRACT FROM AUTHOR]

Biomass conversion to value added chemicals to be used as industrial platform molecules for further synthesis of commodity chemicals has opened new window for scientists. Biomass is a lignocellulosic compound and it requires technological development since biomass is a complex molecule of linear, cyclic and aromatic hydrocarbons. Lignin being aromatic in nature can beneficial for the production of phenolic hydrocarbons. In this work conversion of Guaiacol, a model lignin compound to different aromatic hydrocarbon is performed over pure silica and alumina silica catalysts e.g. SBA-15and ZSM-5 in a fixed bed catalytic reactor. SBA-15 material was synthesized at different aging time leading to improvement in surface area and pore diameter whereas ZSM-5 was pre-treated with H3PO4 and KOH to modify their acidic strength. Maximum Guaiacol conversion in absence of catalyst was obtained aa 90.1 % at 550oC, 97.33 % at 550 °c in presence of SBA-15 (C) and 95.33 % in presence of P/ZSM-5, indicating the catalyst helps in enhancing the conversion, however depends on the type of catalysts and its properties like surface area, pore diameter and Lews/Bronsted acid strength. Similarly the selectivity of catechol was observed to be maximum with SBA-15 (C) as compared to other catalyst owing to its high surface area and large pore diameter. The GCMS analysis of the liquid product obtained includes Dimethyl phenol, 2-dimethoxy benzene, 2-ethyl,5-methyl phenol, catechol, Ethynylanisole and O-cresol

Abstract Background Lignin is a highly abundant but strongly underutilized natural resource that could serve as a sustainable feedstock for producing chemicals by microbial cell factories. Because of the heterogeneous nature of the lignin feedstocks, the biological upgrading of lignin relying on the metabolic routes of aerobic bacteria is currently considered as the most promising approach. However, the limited substrate range and the inefficient catabolism of the production hosts hinder the upgrading of lignin-related aromatics. Particularly, the aerobic O-demethylation of the methoxyl groups in aromatic substrates is energy-limited, inhibits growth, and results in carbon loss in the form of CO2. Results In this study, we present a novel approach for carbon-wise utilization of lignin-related aromatics by the integration of anaerobic and aerobic metabolisms. In practice, we employed an acetogenic bacterium Acetobacterium woodii for anaerobic O-demethylation of aromatic compounds, which distinctively differs from the aerobic O-demethylation; in the process, the carbon from the methoxyl groups is fixed together with CO2 to form acetate, while the aromatic ring remains unchanged. These accessible end-metabolites were then utilized by an aerobic bacterium Acinetobacter baylyi ADP1. By utilizing this cocultivation approach, we demonstrated an upgrading of guaiacol, an abundant but inaccessible substrate to most microbes, into a plastic precursor muconate, with a nearly equimolar yields (0.9 mol/mol in a small-scale cultivation and 1.0 mol/mol in a one-pot bioreactor cultivation). The process required only a minor genetic engineering, namely a single gene knock-out. Noticeably, by employing a metabolic integration of the two bacteria, it was possible to produce biomass and muconate by utilizing only CO2 and guaiacol as carbon sources. Conclusions By the novel approach, we were able to overcome the issues related to aerobic O-demethylation of methoxylated aromatic substrates and demonstrated carbon-wise conversion of lignin-related aromatics to products with yields unattainable by aerobic processes. This study highlights the power of synergistic integration of distinctive metabolic features of bacteria, thus unlocking new opportunities for harnessing microbial cocultures in upgrading challenging feedstocks.

Copyright of Mycosystema is the property of Mycosystema Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in New & Renewable Energy is the property of Editorial Office of Advances in New & Renewable Energy and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

P2O5 has been widely used as an acid‐base catalyst for the O‐methylation of catechol to guaiacol due to its suitable acid strength; however, its stability, which is a significant concern for industrial applications, has not seen significant breakthroughs. Herein, we developed a facile impregnation strategy to synthesize Ce promote P2O5 supported on mesoporous silica (CeP/SBA). The CeP/SBA‐500 carbonized at 500 °C exhibited the highest catalytic activity with a catechol conversion of 71.5 %. The high activity stems from the addition of Ce, forming CePO4, which exhibits improved surface acidity compared to P2O5. Importantly, chemisorption and in situ infrared studies revealed that CePO4 shows stronger adsorption of catechol, which then rapidly converts to guaiacol. The CeP/SBA‐500 exhibits excellent stability with no activity decrease after 10 h of continuous flow reaction, attributed to the absence of a decrease in CePO4 surface acidity. [ABSTRACT FROM AUTHOR]

The potential for grapes and wine to be tainted following vineyard exposure to wildfire smoke is well established, with recent studies suggesting hops and apples (and thus beer and cider) can be similarly affected. However, the susceptibility of other crops to 'smoke taint' has not yet been investigated. Smoke was applied to a selection of fruits and vegetables, as well as potted lavender plants, and their volatile phenol composition determined by gas chromatography–mass spectrometry to evaluate their susceptibility to contamination by smoke. Volatile phenols were observed in control (unsmoked) capsicum, cherry, lavender, lemon, spinach and tomato samples, typically at ≤18 µg/kg, but 52 µg/kg of guaiacol and 83–416 µg/kg of o- and m-cresol and 4-methylsyringol were detected in tomato and lavender samples, respectively. However, significant increases in volatile phenol concentrations were observed as a consequence of smoke exposure; with the highest volatile phenol levels occurring in smoke-exposed strawberry and lavender samples. Variation in the uptake of volatile phenols by different crops was attributed to differences in their physical properties, i.e., their surface area, texture and/or cuticle composition, while the peel of banana, lemon, and to a lesser extent apple samples, mitigated the permeation of smoke-derived volatile phenols into pulp. Results provide valuable insight into the susceptibility of different crops to smoke contamination. [ABSTRACT FROM AUTHOR]

Cigarette butts (CBs) are small residues with mixed composition. Produced in large amounts, their accumulation in the environment has become alarming. It is possible to classify more than 7000 chemical components generated either in the burning process or when distilled from the tobacco. The aim of this work was to describe the rate of release of phenolic compounds from CBs, to determine the content of these compounds in freshly smoked CBs and to monitor the release of phenols from CBs into fresh natural waters. The kinetics of release of selected phenolic compounds (hydroquinone, resorcinol, pyrocatechol, phenol, guaiacol, o-cresol, m-cresol, p-cresol) into water was monitored for 48 h. More than 90% of the content was extracted within 10 h for all analytes. The phenolic content was determined in the CBs of five different brands. The total content of phenols determined for each sample of freshly smoked CB was 215–861 µg/CB. For all CBs analysed, phenol, pyrocatechol and hydroquinone were the most abundant analytes, accounting for up to 75% of the content of all phenols determined. Phenol was the most abundant analyte (64.6–267.8 µg/CB) in all analysed samples. The content of pyrocatechol, the second most abundant analyte, was 45.6–221.2 µg/CB and the third most abundant analyte was hydroquinone (41.71–157.5 µg/CB). Monitoring the release of phenols from CBs into fresh natural waters (river, stream, pond) under steady and slight moving conditions showed that the kinetics of release is not influenced by the type of water. On the contrary, the process of decomposition of the released compounds is influenced by the type of water. The maximum concentrations of individual phenols in CBs extracts were comparable to those determined via laboratory extraction, thus indicating that within 72 h, most of the phenolic compounds are released from CBs into natural water. This research provides missing information on the phenolic content in CBs and the rate of release into water. It thus complements previously published information on CBs as a source of environmental contamination. [ABSTRACT FROM AUTHOR]

Background: Lignin is a highly abundant but strongly underutilized natural resource that could serve as a sustainable feedstock for producing chemicals by microbial cell factories. Because of the heterogeneous nature of the lignin feedstocks, the biological upgrading of lignin relying on the metabolic routes of aerobic bacteria is currently considered as the most promising approach. However, the limited substrate range and the inefficient catabolism of the production hosts hinder the upgrading of lignin-related aromatics. Particularly, the aerobic O-demethylation of the methoxyl groups in aromatic substrates is energy-limited, inhibits growth, and results in carbon loss in the form of CO2. Results: In this study, we present a novel approach for carbon-wise utilization of lignin-related aromatics by the integration of anaerobic and aerobic metabolisms. In practice, we employed an acetogenic bacterium Acetobacterium woodii for anaerobic O-demethylation of aromatic compounds, which distinctively differs from the aerobic O-demethylation; in the process, the carbon from the methoxyl groups is fixed together with CO2 to form acetate, while the aromatic ring remains unchanged. These accessible end-metabolites were then utilized by an aerobic bacterium Acinetobacter baylyi ADP1. By utilizing this cocultivation approach, we demonstrated an upgrading of guaiacol, an abundant but inaccessible substrate to most microbes, into a plastic precursor muconate, with a nearly equimolar yields (0.9 mol/mol in a small-scale cultivation and 1.0 mol/mol in a one-pot bioreactor cultivation). The process required only a minor genetic engineering, namely a single gene knock-out. Noticeably, by employing a metabolic integration of the two bacteria, it was possible to produce biomass and muconate by utilizing only CO2 and guaiacol as carbon sources. Conclusions: By the novel approach, we were able to overcome the issues related to aerobic O-demethylation of methoxylated aromatic substrates and demonstrated carbon-wise conversion of lignin-related aromatics to products with yields unattainable by aerobic processes. This study highlights the power of synergistic integration of distinctive metabolic features of bacteria, thus unlocking new opportunities for harnessing microbial cocultures in upgrading challenging feedstocks. [ABSTRACT FROM AUTHOR]

Expanded polystyrene foam (EPS) contributes to environmental problems due to its inability to decompose in nature within a short period. In addition, petroleum as a core source for EPS is now depleting and new biological and environmentally friendly approaches are encouraged. As an alternative to EPS, mycelium-based biofoam (MBF) is a new foam technology formed of agricultural biomass and mycelium as a binding matrix is introduced. However, based on previous literature, the fungal strains used are mainly highlighted as one of the main factors which affect the final properties of MBF. Thus, this study aims to evaluate the most potential fungus used for MBF application using OPEFB, biomass from the palm oil industry as novel substrate using rapid screening. Twelve local fungi isolated from a local forest in Selangor, Malaysia were cultivated on Potato Dextrose Agar and OPEFB plate before being screened on agar containing four different types of dye indicators, which are methylene blue, guaiacol, Remazol Brilliant Blue R and azure B. As a result, Phanerochaete concrescens isolate LYN-UPM S1 and Perenniporia subtephropora isolate LYN-UPM S9 have shown the ability to produce ligninolytic enzymes and high content of chitin, which will be useful for the fabrication of mycelium-based biofoam. [ABSTRACT FROM AUTHOR]

Water shortage induces physiological, biochemical, and molecular alterations in plant leaves that play an essential role in plant adaptive response. The effects of drought and post-drought rewatering on the activity of antioxidant enzymes and levels of H2O2, phenolic compounds, ascorbic acid, and proline were studied in six local tomato (Solanum lycopersicum L.) varieties. The contents of H2O2 and ascorbic acid increased in all drought-exposed tomato plants and then decreased upon rewatering. The level of phenolic compounds also decreased in response to water shortage and then recovered upon rehydration, although the extent of this response was different in different varieties. The activities of ascorbate peroxidase (APX) and guaiacol peroxidase (POX) and the content of proline significantly increased in the drought-stressed plants and then decreased when the plants were rewatered. The activities of 8 constitutive APX isoforms and 2 constitutive POX isoforms varied upon exposure to drought and were observed after rewatering in all studied varieties. The information on the response of tomato plants to drought and subsequent rewatering is of great importance for screening and selection of drought-tolerant varieties, as well as for development of strategies for increasing plant productivity under adverse environmental conditions. [ABSTRACT FROM AUTHOR]

Lactobionic acid (LBA) has diverse number of applications in pharmaceutical, food, chemical and nanotechnology fields. Bioproduction of LBA by bi-enzymatic cellobiose dehydrogenase (CDH)/laccase (LAC) is a system where CDH catalyses oxidation of lactose to LBA, whilst LAC has, at the same time, ability to regenerate the redox mediator as electron acceptor for CDH. In this study, CDH mutants derived from Phanerochaete chrysosporium produced in Pichia pastoris were used to determine LBA production rate with varying number of redox mediators. The highest specific productivity was observed for triple mutant CDH (tmCDH) for all redox mediators used in this study. The notable redox mediator was hydroquinone where specific productivity was 29.14 g L−1 kU−1 for tmCDH while specific productivity with DCIP was 27.2 g L−1 kU−1, with ABTS showed 19.1 g L−1 kU−1. Lactobionic acid production using bi-enzymatic system, CDH/LAC. Regeneration of different redox mediators. Recombinant mutants used in reaction system. [ABSTRACT FROM AUTHOR]

In order to contribute to the shift from petro-based chemistry to biobased chemistry, necessary to minimize the environmental impacts of the chemical industry, 2-methoxy-4-vinylphenol (4-vinyl guaiacol, 4VG) was used to synthesize a platform of biobased monomers. Thus, nine biobased monomers were successfully prepared. The synthesis procedures were investigated through the green metrics calculations in order to quantify the sustainability of our approaches. Their radical homopolymerization in toluene solution initiated by 2,2′-azobis(2-methylpropionitrile) (AIBN) was studied and the effect of residual 4VG as a radical inhibitor on the kinetics of polymerization was also explored. The new homopolymers were characterized by proton nuclear magnetic resonance (1H-NMR) spectroscopy, size exclusion chromatography and thermal analyses (dynamical scanning calorimetry DSC, thermal gravimetric analysis TGA). By varying the length of the alkyl ester or ether group of the 4VG derivatives, homopolymers with Tg ranging from 117 °C down to 5 °C were obtained. These new biobased monomers could be implemented in radical copolymerization as substitutes to petro-based monomers to decrease the carbon footprint of the resulting copolymers for various applications. [ABSTRACT FROM AUTHOR]

The hydrogenation reaction of guaiacol in the gas phase at 300 °C and atmospheric pressure of hydrogen was investigated over Ni-based catalysts supported on niobium oxide (Nb2O5) and exfoliated potassium hexaniobate (Nb-exf). The catalysts were prepared by two different methods: photodeposition (pd) and incipient wetness impregnation (im) and were characterized by N2 adsorption–desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and temperature-programmed desorption of ammonia (NH3-TPD) analyses. XRD analysis showed that all catalysts exhibited approximately the same crystallite size of the metallic nickel (15 nm). Regarding the catalytic tests, guaiacol was mainly converted to catechol (59.5–80.6%) and phenol (4.4–14.2%) regardless of the catalyst. Small amounts of benzene were only observed over Ni(im)/Nb2O5. The catalytic experiments showed that the main reaction pathway is the conversion of guaiacol through demethylation reaction producing catechol followed by phenol formation via dehydroxylation reaction. Ni(im)/Nb2O5 was tested for catalytic upgrading of pyrolysis vapor of different biomasses (lignin, microalgae, and malt residue), and it was able to reduce the yield of oxygenated products. The catalytic upgrading of pyrolysis vapor of microalgae using a catalyst-to-biomass weight ratio (C:B) of 3:1 showed the highest selectivity of hydrocarbons (57.44%). The catalyst concentration and the biomass used in the test showed a high influence on the product distribution. [ABSTRACT FROM AUTHOR]

Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In a bushfire burning of plant material generates volatile phenolics that may be absorbed by berries and leaves of grapes in nearby vineyards. In grapes these phenolics form glycoconjugates and the undesirable sensory attributes of smoke-exposed grapes only develop post-fermentation in the wine making process, when the free phenolics are released. To reduce the financial losses from producing smoke-tainted wines, phenolic glycosides associated with smoke-taint in grapes are currently monitored in analytical laboratories. Here, we performed LC-MS analysis on extracts of diverse grape varieties of various geographic sites and with varying levels of smoke taint exposure. Discovery of smoke-taint biomarkers, based on untargeted analysis led to the identification of additional phenolic compounds that could contribute significantly to the smoke-tainted flavour of wine. A total of 73 differentially expressed metabolites were detected and LCMSMS analysis resulted in the structural assignment of 15 compounds, including guaiacol and syringol derivatives and novel glycoconguate intermediaries.

Bio-crude oil is known to be sustainable, eco-environmentally, and an alternative energy source produced by biomass pyrolysis. However, its quality remains relatively low due to a higher oxygen concentration compared to liquid fuels from fossils. Therefore, an upgrading process is necessary through the catalytic hydrodeoxygenation (HDO) process. This work synthesized pillared bentonite using Al and Ti metals as the pillaring agent to produce Al-PILC and Ti-PILC as catalyst support for sulfided NiMo. Their catalytic activity in HDO reaction using guaiacol as a model compound of bio-crude oil were also evaluated. Characterization of the bentonite-pillared materials, including Al-PILC, Mo/Al-PILC, NiMo/Al-PILC, Ti-PILC, Mo/Ti-PILC, and NiMo/Ti-PILC, was performed using Surface Area Analyzer, X-ray Diffractometer (XRD), Temperature-Programmed Desorption of ammonia (NH3-TPD), X-Ray Fluorescence (XRF), and Scanning Electron Microscope (SEM) techniques. The characterization results confirm the pillarization process of bentonite using Al and Ti metals as the pillaring agent, and the preparation of the NiMo catalyst using the stepwise impregnation method was successfully prepared. The NiMo/Ti-PILC catalyst performs a superior conversion value on the HDO guaiacol reaction than other catalysts. A well dispersion of Mo and Ni metals on the surface support (NiMo/Ti-PILC), thus creating numerous active sites of the catalyst after the sulfidation. Variations in time and temperature during the HDO guaiacol reaction significantly affected the conversion.

Vanillin (4-hydroxy-3-methoxybenzaldehyde) is an important platform chemical compound that is invariably produced from pyrolysis of various categories of biomass. Hydrodeoxygenation (HDO) of vanillin has been a thematic topic in catalysis with the underlying aim to devise processes and reactions for catalytic upgrading of bio-oil and in the production of value-added products. Herein, we investigate the HDO of an evaporated stream of vanillin over a 4 % load of palladium supported on ceria; a Pd/CeO2 catalyst. The synthesized catalyst was characterized by various techniques including XRD, XPS, EDX-SEM, HR-TEM, and TPR. The HDO reaction (carried out at temperatures from 100 °C to 300 °C at 10 °C/min ramp rate with a 5 % H2 feed ratio) resulted in a 95 % conversion of vanillin with an 85 % yield of guaiacol (2-methoxyphenol). Minute loads of alkylbenzene compounds (mainly xylene and ethylbenzene) also emerged. DFT computations elucidate pathways for the observed formation of guaiacol where synergistic effects of both Pd and vacant oxygen sites are highlighted. Overall, we presented a viable HDO route for an oxygenated biomass model compound at mild operational conditions (intermediate temperatures, ambient pressure, and moderate H2/Feed ratio).

The various mechanisms of primary antioxidant action of a series of 2‐Methoxyphenols are investigated in the present work. The electronic properties have just been studied in a joint article, so that we focus here on Hydrogen Atom Transfer (HAT), Single Electron Transfer–Proton Transfer (SET–PT) and Sequential Proton‐Loss Electron‐Transfer (SPLET) mechanisms. The two computational approaches used in the previous study of the structure and reactivity of these compounds [Computational and Theoretical Chemistry 1229 (2023) 114287] provide identical mechanisms trends in gas phase. In gas media, hydrogen atom transfer (HAT) is more favored. On the contrary, the solvent polarity has a significant effect on the mechanism of the antioxidant activity, since the polarity of the solvent increases the contribution of the SPLET mechanism. [ABSTRACT FROM AUTHOR]

Highly efficient and low-cost bio-oil upgrading process is critical for the realization of renewable biomass as the substitution for fossil oil in the production of biofuel. In this study, a highly dispersed Co/SiO2–Al2O3 catalysts were prepared by simple wet impregnation, and its catalytical activity in the hydrodeoxygenation of guaiacol, one of the most key reactions of bio-oil upgrading, was evaluated. The as-prepared catalyst could provide a full conversion of guaiacol (100%) and 96.8% selectivity of cyclohexane under relatively mild conditions (250 °C, 2-MPa H2, 1 h). The characterizations of the as-prepared Co/SiO2–Al2O3 catalyst confirmed a highly dispersed Co particle with the SiO2–Al2O3 support, which favored the selectivity of cyclohexane. In addition, both the synergy of Co0 and Coδ+ species and the medium-strength acidic sites contributed to the high catalytical performance of the catalyst. According to the distribution of the products, the reaction path from guaiacol to cyclohexane was speculated. Furthermore, the Co/SiO2–Al2O3 catalyst also possessed high stability and versatility. The above properties together with the easy preparation method entitled the Co/SiO2–Al2O3 catalyst great potential as a non-noble metal catalyst for the scale-up applications in bio-oil upgrading process. [ABSTRACT FROM AUTHOR]

Lignin, an abundant aromatic polymer in nature, has received significant attention for its potential in the production of bio-oils and chemicals owing to increased resource availability and environmental issues. The hydrodeoxygenation of guaiacol, a lignin-derived monomer, can produce cyclohexanol, a nylon precursor, in a carbon-negative and environmentally friendly manner. This study explored the porous properties and the effects of activation methods on the Ru-based catalyst supported by environmentally friendly and cost-effective hydrochar. Highly selective cleavage of Caryl-O bonds was achieved under mild conditions (160 °C, 0.2 MPa H2, and 4 h), and alkali activation further improved the catalytic activity. Various characterization methods revealed that hydrothermal treatment and alkali activation relatively contributed to the excellent performance of the catalysts and influenced their porous structure and Ru dispersion. X-ray photoelectron spectroscopy results revealed an increased formation of metallic ruthenium, indicating the effective regulation of interaction between active sites and supports. This synergistic approach used in this study, involving the valorization of cellulose-derived hydrochar and the selective production of nylon precursors from lignin-derived guaiacol, indicated the comprehensive and sustainable utilization of biomass resources. [ABSTRACT FROM AUTHOR]

The objective of this work was the isolation and characterization of Alicyclobacillus acidoterrestris strains from orange juice. In all, 72 isolates were recovered from commercial orange juice bought from the Greek market. The isolates were subjected to polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) to discriminate them at strain level and A. acidoterrestris types I and II. The restriction patterns of 16S rRNA gene revealed that isolates were categorized in different groups depending on the restriction endonucleases. Moreover, the digestion of the part of vdc operon gene with Hph I restriction enzyme successfully differentiated between A. acidoterrestris types I and II. In conclusion, RFLP succeeded in differentiating A. acidoterrestris isolates at strain and type levels. [ABSTRACT FROM AUTHOR]

A new type of benzoxazine resin has been synthesized using a natural phenol source, guaiacol, and a biomass amines, furfuramine. The synthesis conditions were optimized; when the reaction molar ratio of guaiacol, furfuramine, and polyformaldehyde was 1:1:4, the highest synthetic yield was reached. The product was characterized via testing using transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), mass spectrogram (MS), and nuclear magnetic resonance (1H-NMR) to confirm its molecular structure. A differential scanning calorimetry (DSC) test was conducted to analyze the thermodynamic properties of the product, and the results showed that the product decomposed and evaporated at around 180 °C, making it impossible to achieve self-curing. However, the prepared guaiacol-furfuramine benzoxazine resin (GFZ) can be blended and cured in certain proportions with bisphenol A-aniline oxazine resin (BAZ) as a GFZ/BAZ binary system (5:95, 10:90, 20:80, and 40:60). Dynamic mechanical analysis (DMA) test results showed that when the content of GFZ was 10%, the storage modulus of the copolymer resin was greatly improved. After conducting impact strength tests on the copolymer resin, it was found that the toughness of the copolymer resin had improved, and the maximum impact strength had increased by nearly three times. This indicates that the flexible long-chain structure in GFZ can effectively improve the toughness of the cured copolymer system. The reaction of active groups on benzoxazine molecules with other resins can not only improve the mechanical properties of their cured products, but also has important significance in the preparation of low-cost and environmentally friendly sustainable composite materials with excellent comprehensive performance. [ABSTRACT FROM AUTHOR]

To replace the noble metals used in hydrodeoxygenation (HDO) catalysts, guaiacol HDO was conducted using various transition metal-loaded catalysts. Co/TiO2 was highly active for guaiacol HDO, enabling a more economic removal of the methoxy groups compared to the Ru/TiO2 catalyst, resulting in superior cyclohexanol selectivity. When a WO3 promoter was added to the Co catalyst to enhance its oxygen removal ability, the conversion of guaiacol was severely reduced because the co-impregnated WOx species decreased the number of exposed Co sites. To avoid this phenomenon, Co and WO3 were isolated by physically mixing Co/TiO2 and WO3/TiO2, where 100% conversion and oxygen removal could be achieved under 10 bar H2 at 250 °C. The cause of the catalyst deactivation was systematically investigated by magnetic separation of the physical mixture of the catalysts after the reaction, followed by a series of characterization studies. Temperature-programmed-oxidation mass spectroscopy and Raman spectroscopy revealed that the deposition of carbonaceous species was the main contributor to the deactivation of WO3/TiO2, and the catalytic activity could be successfully recovered by simple calcination at 400 °C. This study provides insights into the development of economical and efficient physically mixed HDO catalysts using transition metals, and contributes to the understanding of the deactivation and regeneration of physically mixed HDO catalysts. [ABSTRACT FROM AUTHOR]

Salicylic acid (SA) is a phytohormone and phenolic antioxidant that plays a role in various physiological and protective responses to biotic and abiotic stresses, including salinity. In this study, we analyzed the influence of 50 μM SA on wheat plants (Triticum aestivum L.) under 100 mM NaCl in a controlled growing experiment. Seed priming resulted in an increased activation of phenylalanine ammonia-lyase (PAL), tyrosine ammonia-lyase (TAL), and guaiacol peroxidase (GPX), as well as the accumulation of endogenous SA and lignin. It is likely that the accumulation of SA is responsible for the growth-stimulating effect of the phytohormone. SA priming led to the accumulation of reduced (GSH) and oxidized glutathione (GSSG) in a balanced manner, without altering the GSH/GSSG ratio, as well as the accumulation of ascorbic acid (ASA), hydrogen peroxide (H2O2), and the activation of glutathione reductase (GR) and ascorbate peroxidase (APX). In addition, these plants also exhibit a slight accumulation of carotenoids (Car) and proline. Under SA treatment, there is a decrease in stress-induced SA accumulation, along with additional lignin accumulation compared to the stress levels. This is accompanied by a decrease in stress-induced activation of PAL, TAL, and GPX. Strengthening the barrier properties of cell walls reduced the damaging effects of salinity on plants. This is evidenced by indicators such as the GSH/GSSG ratio, ASA and H2O2 content, Car levels, and the activation of APX and GR enzymes. Additionally, the state of membrane structures (MDA content and electrolyte leakage) and growth indicators also support this finding. The obtained data conclusively point to the realization that physiological and protective effects of SA are attributed to its ability to regulate its endogenous content, modify cell wall state, and reduce the damaging effects of stress on the state of the ascorbate-glutathione complex in wheat plants. [ABSTRACT FROM AUTHOR]

To improve and develop our monotherapeutic approach for Helicobacter pylori infection, some Schiff base compounds containing eugenol and guaiacol were synthesized and their antioxidant capacities, urease enzyme inhibition, and Anti-Helicobacter pylori effect were investigated and compared with azo analogs in the literature. All Schiff base compounds have been found to have both stronger urease enzyme inhibitory and more effective Anti-Helicobacter pylori properties than its azo analogs. In particular, the antimicrobial effect of Schiff bases containing eugenol increased dramatically when compared to their azo analogs. [ABSTRACT FROM AUTHOR]

Aim. The present study evaluated the therapeutic effects of luteolin in alleviating pulpitis of dental pulp- (DP-) derived microvesicles (MVs) via the inhibition of protein kinase R- (PKR-) mediated inflammation. Methodology. Proteomic analysis of immortalized human dental pulp (DP-1) cell-derived MVs was performed to identify PKR-associated molecules. The effect of luteolin on PKR phosphorylation in DP-1 cells and the expression of tumor necrosis factor-α (TNF-α) in THP-1 macrophage-like cells were validated. The effect of luteolin on cell proliferation was compared with that of chemical PKR inhibitors (C16 and 2-AP) and the unique commercially available sedative guaiacol-parachlorophenol. In the dog experimental pulpitis model, the pulps were treated with (1) saline, (2) guaiacol-parachlorophenol, and (3) luteolin. Sixteen teeth from four dogs were extracted, and the pulp tissues were analyzed using hematoxylin and eosin staining. Immunohistochemical staining was performed to analyze the expression of phosphorylated PKR (pPKR), myeloperoxidase (MPO), and CD68. Experimental endodontic-periodontal complex lesions were established in mouse molar through a silk ligature and simultaneous MV injection. MVs were prepared from DP-1 cells with or without pretreatment with 2-AP or luteolin. A three-dimensional microcomputed tomography analysis was performed on day 7 (n = 6). Periodontal bone resorption volumes were calculated for each group (nonligated–ligated), and the ratio of bone volume to tissue volume was measured. Results. Proteomic analysis identified an endogenous PKR activator, and a protein activator of interferon-induced PKR, also known as PACT, was included in MVs. Luteolin inhibited the expressions of pPKR in DP-1 cells and TNF-α in THP-1 cells with the lowest suppression of cell proliferation. In the dog model of experimental pulpitis, luteolin treatment suppressed the expression of pPKR-, MPO-, and CD68-positive cells in pulp tissues, whereas guaiacol-parachlorophenol treatment caused coagulative necrosis and disruption. In a mouse model of endodontic-periodontal complex lesions, luteolin treatment significantly decreased MV-induced alveolar bone resorption. Conclusion. Luteolin is an effective and safe compound that inhibits PKR activation in DP-derived MVs, enabling pulp preservation. [ABSTRACT FROM AUTHOR]

Dependences of the components of the complex dielectric permittivity and specific electrical conductivity in the frequency range 10−2–107 Hz at temperatures of 213–433 K of guaiacol, a model compound of lignin, one of the most common biopolymers, are analyzed. Three groups of relaxation oscillators are identified. Their characteristics (relaxation time and activation energy) are determined. The activation energy is shown to change depending on the aggregate state. The results indicate that the dielectric relaxation and conductivity of lignin polymer and its model compounds are similar in an alternating electric field. [ABSTRACT FROM AUTHOR]

The local isolate TY10 was derived from a soil sample that was polluted with oil in a previous investigation. The study focused on evaluating the isolate's capacity to manufacture the laccase enzyme. The Bacillus cereus isolate was identified based on the findings of morphological and biochemical testing, as well as the VITEK-2 tests. The synthesis of laccase by the Bacillus cereus TY10 isolate was assessed using qualitative and quantitative methods, with guaiacol serving as a substrate indicator. The qualitative investigation revealed that the local isolate TY10 exhibited a strong capacity for laccase enzyme production in the solid medium. Simultaneously, it was shown that the indigenous strain Bacillus cereus TY10 exhibited an enzyme activity of 0.98 units/ml when the broth of the indigenous strain was utilised in quantitative measurements for enzyme synthesis. The impact of different durations of incubation, pH values, and the current research focused on examining temperatures and their impact on the ability of a local entity Bacillus cereus TY10 Extract laccase enzyme by isolation. The study discovered that laccase production reached its peak of 1.61 Unit/ml occurred after 48 hours of incubation at 35°C, using a growth medium with a pH of 7. The crude laccase enzyme underwent a purification procedure consisting of three sequential steps: Ammonium sulphate precipitation and two gel filtration steps using Sephadex G-25 and G-100. This process resulted in a 6.52 times purification of the laccase enzyme, with a recovery rate of 90.65% and a specific activity of 39.98 unit/mg protein. All purification steps contributed to this outcome. [ABSTRACT FROM AUTHOR]

Fifteen transgenic shoot clones (TS A-TS O) regenerated from Hypericum perforatum hairy roots were evaluated for growth characteristics, phenylpropanoid, and naphthodianthrone production, as well as non-enzymatic and enzymatic antioxidant status. Transgenic shoots displayed higher biomass production and non-altered phenotypes compared to control shoots. Phenylpropanoid production in TS was not related to phenylalanine ammonia lyase activity indicating that alternative enzymes could be involved in the regulation of phenylpropanoid/flavonoid biosynthesis. The positive correlation between phenylpropanoids (phenolic acids, flavonoids, flavan-3-ols, tannins) and non-enzymatic antioxidant assays suggested that these compounds are the main contributors to the redox state and radical scavenging properties of TS clones. More importantly, enhanced naphthodianthrone production (hypericin, pseudohypericin and protopseudohypericin) in TS was associated with the number of leaf dark glands. Concerning the enzymatic antioxidant status of TS, guaiacol peroxidase was shown as the main enzyme that turns down H2O2 levels, while the upregulation of superoxide dismutase coincided with decreased O2•− production. The efficiency of antioxidant enzymes for O2•− and H2O2 neutralization decreased the level of MDA and consequently delayed lipid peroxidation in TS clones. Altogether, H. perforatum transgenic shoots could be proposed as a prospective biotechnological system for scale-up production of naphthodianthrones and phenylpropanoids with antioxidant properties. [ABSTRACT FROM AUTHOR]

The mechanism behind the hydrodeoxygenation (HDO) of guaiacol on Co(0001), Ni(111), Cu(111), Pd(111), and Pt(111) was investigated by constructing a first‐principles microkinetic model from density functional theory (DFT) models for 68 possible intermediates over each surface. We report that the most energetically favorable pathway for this process is the demethylation of guaiacol to catechol over Ni(111), which exhibits highly desirable deoxygenation and hydrogenation kinetics at industrial temperatures. Guaiacol readily undergoes hydrogenation over Pt(111) and Pd(111), but the products exhibit slow desorption from the surfaces at standard operation temperatures. Furthermore, the deoxygenation pathway is hindered by the high energy barrier associated with the scission of the Calkyl−O bond. [ABSTRACT FROM AUTHOR]

Metarhizium robertsii microsclerotia are fungal aggregates composed of compacted, pigmented hyphae. As they are highly tolerant to desiccation and produce infective conidia, they are promising candidates to be formulated as bioinsecticides. Despite this potential, the nature of the pigments within these structures remains unclear. In this study, routine culture media used for the differentiation of M. robertsii microsclerotia were supplemented with four melanin inhibitors, and the resulting propagules were characterized. Inhibitors of the 1,8-dihydroxynaphthalene (DHN)-melanin biosynthetic pathway such as tricyclazole and guaiacol induced significant phenotypic and molecular modifications in the obtained M. robertsii propagules, which exhibited a more spherical shape, reduced size, and increased susceptibility to desiccation, heat, and oxidative stress than microsclerotia obtained without inhibitors. Additionally, genes encoding for a polyketide synthase (Mrpks2) and a putative 1,3,6,8-tetrahydroxynaphthalene reductase (Mrthnr), potentially involved in the DHN-melanin biosynthetic pathway, were upregulated in fungi grown in the inhibitor-added media. In conclusion, M. robertsii microsclerotia contain melanins of type DHN that might play a role in both microsclerotia differentiation and environmental stress tolerance. [ABSTRACT FROM AUTHOR]

The culture liquid of lactic-acid bacteria (LABs) and bifidobacteria contained secondary metabolites fulfilling signal functions, such as guaiacol and γ-butyrolactone. In addition, 4-hexylresorcinol was detected in the cell extract of Bifidobacterium bifidum 791. No homoserine lactones were produced by the tested microorganisms. The presence of metabolites with signal functions in conjunction with the available data on the synthesis of neuroactive amines, amino acids, and prebiotics by LABs and bifidobacteria indicates that these bacteria can strongly influence the functioning of the whole human symbiotic microbiota as well as the human host's health state. [ABSTRACT FROM AUTHOR]

Bifunctional catalysts are a major type of heterogeneous catalytic systems that have been widely investigated for biomass upgrading. In this work, Ru-catalysts based on sulfonated porous aromatic frameworks (PAFs) were used in the hydrodeoxygenation (HDO) of lignin-derived compounds: guaiacol, veratrole, and catechol. The relationship between the activity of metal nanoparticles and the content of acid sites in synthesized catalysts was studied. Herein, their synergy was demonstrated in the Ru-PAF-30-SO3H/5-COD catalyst. The results revealed that this catalytic system promoted partial hydrogenation of lignin-based compounds to ketones without any further transformations. The design of the Ru-PAF-30-SO3H/5-COD catalytic system opens a promising route to the selective conversion of lignin model compounds to cyclohexanone. [ABSTRACT FROM AUTHOR]

Background: The article aim was biosynthesis of zinc nanoparticles by the fruit and stem of Capparis Spinosa plant extract and the investigation of growth factors and some physiological properties of the M. Oleifera plant. Methods: Four levels of zinc nanoparticles (0, 125, 250, and 500) ppm were considered as treatments. Water extract of the Capparis Spinosa plant were obtained using 10 grams of stem and fruit were separately dried. Some properties like below information were measured: Ultraviolet-visible spectroscopic analysis, Infrared spectroscopy, Measurement of chlorophyll a and b and carotenoids, total phenol, antioxidant activity, total protein and antioxidant enzymes. The data of this research were factorially conducted in the form of completely randomized blocks with three replications. Results: The effect of zinc nanoparticles on growth parameters shows that the length and weight of the shoot and root are significant at the five percent probability level. Also, the length and dry weight of shoots and roots are significant at the five percent probability level. The effect of zinc nanoparticles on the concentration of chlorophyll a, chlorophyll b and carbohydrates is significant at the five percent probability level. The main effect of zinc nanoparticles on the amount of total phenol, flavonoid, and DPPH of the M. Oleifera medicinal plant was significant. The effect of stem and fruit extract of zinc nanoparticles on the amount of ascorbate peroxidase, catalase, and guaiacol oxidase enzymes. Conclusion: The results showed that nano made from fruit and stem significantly increases root length, protein content and total phenol content, and activity of catalase and ascorbate peroxidase enzymes. [ABSTRACT FROM AUTHOR]

The depolymerisation of softwood kraft lignin was investigated, under hydrothermal conditions at 290 °C and 250 bar, with guaiacol in the reactor feed to evaluate its impact on the formation of char and on the molecular weights of the products. The effect of residence time was investigated in the time span 1–12 min. Lignin is depolymerised during the process and guaiacol is both formed and consumed during the reaction, with clearly noticeable changes as early as in the first minute of reaction. Although the addition of guaiacol in the reactor feed causes a reduction in the weight average molecular weight of the products, the yield of char increases. Longer residence times result in repolymerisation of the reaction products as well as a further increase in the yield of monoaromatic components and char. [ABSTRACT FROM AUTHOR]

A series of six composites was prepared from the reaction of lignin-derived guaiacol, fatty acids, and sulfur. In this preparation, the organic comonomers undergo C–S bond-forming reactions to establish a highly crosslinked network material in which some non-covalently incorporated sulfur species are also entrapped. Both monounsaturated oleic acid and diunsaturated linoleic acid were used as fatty acid components to assess the influence of their unsaturation levels on composite properties. The ratio of organics and the proportion of sulfur (70 or 80 wt%) was also varied to assess the effect on thermal, morphological, and mechanical properties. Thermogravimetric analysis showed that composites exhibited good thermal stability up to ~220 °C. Differential scanning calorimetry revealed that the materials generally exhibit melting features for entrapped cyclo-S8, cold crystallization features for some materials, and a composition-dependent glass transition temperature. The flexural and compressive strengths of the composites revealed that some of the composites exhibit strengths significantly higher than those required of Portland cements used in residential housing fabrication and may be more sustainable structural materials. The thermal and mechanical properties could be tailored by changing the degree of unsaturation of the fatty acid comonomer or by altering the percentage of fatty acid in the monomer feed. The highest mechanical strength was achieved with greater amounts of monounsaturated oleic acid comonomer. [ABSTRACT FROM AUTHOR]

Fungi are producers of lignolytic extracellular enzymes which are used in industries like textile, detergents, biorefineries, and paper pulping. This study assessed for the production, purification, and characterization of novel p-diphenol oxidase (PDO; laccase) enzyme from lignolytic white-rot fungal isolate. Fungi samples collected from different areas of Pakistan were initially screened using guaiacol plate method. The maximum PDO producing fungal isolate was identified on the basis of ITS (internal transcribed spacer sequence of DNA of ribosomal RNA) sequencing. To get optimum enzyme yield, various growth and fermentation conditions were optimized. Later PDO was purified using ammonium sulfate precipitation, size exclusion, and anion exchange chromatography and characterized. It was observed that the maximum PDO producing fungal isolate was Schizophyllum commune (MF-O5). Characterization results showed that the purified PDO was a monomeric protein with a molecular mass of 68 kDa and showed stability at lower temperature (30 °C) for 1 h. The Km and Vmax values of the purified PDO recorded were 2.48 mM and 6.20 U/min. Thermal stability results showed that at 30 °C PDO had 119.17 kJ/K/mol Ea value and 33.64 min half-life. The PDO activity was stimulated by Cu2+ ion at 1.0 mM showing enhanced activity up to 111.04%. Strong inhibition effect was noted for Fe2+ ions at 1 mM showing 12.04% activity. The enzyme showed stability against 10 mM concentration oxidizing reducing agents like DMSO, EDTA, H2O2, NaOCl, and urea and retained more than 75% of relative activity. The characterization of purified PDO enzyme confirmed its tolerance against salt, metal ions, organic solvents, and surfactants indicating its ability to be used in the versatile commercial applications. [ABSTRACT FROM AUTHOR]

The study provides valuable insights for the potential of coconut shell as a renewable energy source for bio-oil production using parabolic solar pyrolysis The primary objectives of this study were to assess the efficacy of parabolic solar pyrolysis in bio-oil production, analyze coconut shells and biochar, conduct pyrolysis experiments, identify parameters influencing pyrolysis, carry out performance tests, and analyze the composition of bio-oil compounds. The research methods used include energy analysis, optimization of parabolic solar pyrolysis systems, performance calculations, analysis of GC/MS of bio-oil compounds, and the assessment of biochar. The proximate analysis of the coconut shells revealed that they consisted of 47.37% fixed carbon, 1.89% ash, 11.32% moisture content, and 77.8% volatile matter. The heating rate during the process was in the range of 5-150°C/min. The factors affecting the performance of parabolic solar pyrolysis include the light radiation intensity, parabolic area, receiver, and reactor material. The temperature generated by the solar pyrolysis concentrator was in the range of 300-650°C. The study found varied bio-oil, biochar, and gas yields influenced by the particle size and pyrolysis temperature. The main compounds in the bio-oil were phenol, furfural, cresol, creosol, syrigol, guaiacol, pentadecanoic acid, and carbonyl compounds. [ABSTRACT FROM AUTHOR]

A series of six composites was prepared from the reaction of lignin-derived guaiacol, fatty acids, and sulfur. In this preparation, the organic comonomers undergo C–S bond-forming reactions to establish a highly crosslinked network material in which some non-covalently incorporated sulfur species are also entrapped. Both monounsaturated oleic acid and diunsaturated linoleic acid were used as fatty acid components to assess the influence of their unsaturation levels on composite properties. The ratio of organics and the proportion of sulfur (70 or 80 wt%) was also varied to assess the effect on thermal, morphological, and mechanical properties. Thermogravimetric analysis showed that composites exhibited good thermal stability up to ~220 °C. Differential scanning calorimetry revealed that the materials generally exhibit melting features for entrapped cyclo-S8, cold crystallization features for some materials, and a composition-dependent glass transition temperature. The flexural and compressive strengths of the composites revealed that some of the composites exhibit strengths significantly higher than those required of Portland cements used in residential housing fabrication and may be more sustainable structural materials. The thermal and mechanical properties could be tailored by changing the degree of unsaturation of the fatty acid comonomer or by altering the percentage of fatty acid in the monomer feed. The highest mechanical strength was achieved with greater amounts of monounsaturated oleic acid comonomer.