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The Oxygenate-Mediated Conversion of CO to Hydrocarbons─On the Role of Zeolites in Tandem Catalysis.Chemical Reviews Oct 2023Decentralized chemical plants close to circular carbon sources will play an important role in shaping the postfossil society. This scenario calls for carbon technologies... (Review)
Review
Decentralized chemical plants close to circular carbon sources will play an important role in shaping the postfossil society. This scenario calls for carbon technologies which valorize CO and CO with renewable H and utilize process intensification approaches. The single-reactor tandem reaction approach to convert CO to hydrocarbons via oxygenate intermediates offers clear benefits in terms of improved thermodynamics and energy efficiency. Simultaneously, challenges and complexity in terms of catalyst material and mechanism, reactor, and process gaps have to be addressed. While the separate processes, namely methanol synthesis and methanol to hydrocarbons, are commercialized and extensively discussed, this review focuses on the zeolite/zeotype function in the oxygenate-mediated conversion of CO to hydrocarbons. Use of shape-selective zeolite/zeotype catalysts enables the selective production of fuel components as well as key intermediates for the chemical industry, such as BTX, gasoline, light olefins, and C alkanes. In contrast to the separate processes which use methanol as a platform, this review examines the potential of methanol, dimethyl ether, and ketene as possible oxygenate intermediates in separate chapters. We explore the connection between literature on the individual reactions for converting oxygenates and the tandem reaction, so as to identify transferable knowledge from the individual processes which could drive progress in the intensification of the tandem process. This encompasses a multiscale approach, from molecule (mechanism, oxygenate molecule), to catalyst, to reactor configuration, and finally to process level. Finally, we present our perspectives on related emerging technologies, outstanding challenges, and potential directions for future research.
PubMed: 37769023
DOI: 10.1021/acs.chemrev.3c00058 -
Molecules (Basel, Switzerland) Jul 2023Asphaltene extracted from heavy oil was oxidized by a mixture of propionic anhydride and hydrogen peroxide at a low temperature of 50 °C. Elemental analysis, infrared...
Asphaltene extracted from heavy oil was oxidized by a mixture of propionic anhydride and hydrogen peroxide at a low temperature of 50 °C. Elemental analysis, infrared analysis, proton nuclear magnetic resonance analysis, and gas chromatograph/mass spectrometer analysis results indicated that oxygen addition, side chain cleavage, and condensation reactions mainly occurred in the oxidation process. The oxidation products were divided into 28% methanol solubles and 72% methanol insolubles. There were mainly fatty acids and fatty acid esters in the methanol solubles. There were also small amounts of aromatic compounds with low condensation in the methanol solubles, and the alkyl side chains were mostly short ones. The degree of aromatic ring condensation in the methanol insolubles was slightly higher than that of the pristine asphaltene. There were still some long unbroken chains in the methanol insolubles after the low-temperature reaction. The molecular dynamics simulation results show that the distribution of propionic anhydride around the asphaltene molecules can promote the oxidation of asphaltene. This low-temperature oxidation technology can be used to process asphaltenes to improve the profitability of heavy-oil-processing enterprises.
PubMed: 37513237
DOI: 10.3390/molecules28145362 -
Molecules (Basel, Switzerland) Sep 2023Conventionally, methanol is the solvent of choice in the synthesis of gamma-cyclodextrin metal-organic frameworks (γ-CD-MOFs), but using ethanol as a replacement could...
Conventionally, methanol is the solvent of choice in the synthesis of gamma-cyclodextrin metal-organic frameworks (γ-CD-MOFs), but using ethanol as a replacement could allow for a more food-grade synthesis condition. Therefore, the aim of the study was to compare the γ-CD-MOFs synthesised with both methanol and ethanol. The γ-CD-MOFs were characterised by scanning electron microscopy (SEM), surface area and pore measurement, Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD). The encapsulation efficiency (EE) and loading capacity (LC) of the γ-CD-MOFs were also determined for curcumin, using methanol, ethanol and a mixture of the two as encapsulation solvent. It was found that γ-CD-MOFs synthesised by methanol and ethanol do not differ greatly, the most significant difference being the larger crystal size of γ-CD-MOFs crystallised from ethanol. However, the change in solvent significantly influenced the EE and LC of the crystals. The higher solubility of curcumin in ethanol reduced interactions with the γ-CD-MOFs and resulted in lowered EE and LC. This suggests that different solvents should be used to deliberately manipulate the EE and LC of target compounds for better use of γ-CD-MOFs as their encapsulating and delivery agents.
PubMed: 37836719
DOI: 10.3390/molecules28196876 -
Scientific Reports Jan 2024The COVID-19 pandemic has substantially affected people and healthcare systems. One of the main challenges was the reduction and change in the pattern of non-COVID-19...
The COVID-19 pandemic has substantially affected people and healthcare systems. One of the main challenges was the reduction and change in the pattern of non-COVID-19 diseases and conditions. Moreover, due to the mental burden of the pandemic, the trend of poisonings and abuses changed. In this study, we aimed to assess the trends of poisonings from different agents before and during the COVID-19 pandemic using the interrupted time series method. This study was conducted at one of the main Tehran referral centers for poisoning, Baharloo Hospital. Pre-COVID-19 period was defined as April 2018 to January 2020 while the COVID-19 time was from February 2020 to March 2022. The total number of monthly poisoning cases in addition to eight categories of drugs/substances/agents were identified, including drugs (such as psychiatric drugs, cardiovascular drugs, and analgesics), opioids, stimulants, methanol, ethanol, cannabis, pesticides, and carbon monoxide. Interrupted time series analysis was performed to compare the pre-pandemic trend of total monthly cases from each category in addition to the proportion (%) of each one. In total, 13,020 cases were poisoned during the study period, among which 6088 belonged to the pre-pandemic period and 6932 were admitted during the COVID-19 era. There was no significant difference in terms of demographic characteristics of patients before and during the pandemic (p-value > 0.05). At the beginning of the pandemic, there was a sudden fall in the number of poisoning patients (- 77.2 cases/month, p-value = 0.003), however, there was a significant increasing trend during the COVID time (3.9 cases/month, p-value = 0.006). Most of the categories had a sharp decrease at the beginning of the pandemic except for methanol and ethanol which had increases, although not significant. Cannabis also had a significant change in slope (- 0.6 cases/month, p-value = 0.016), in addition to the sudden decrease at the beginning of the pandemic (- 10 cases/month, p-value = 0.007). Regarding the proportion of each category from total monthly poisoning cases, methanol, and ethanol had immediate rises of 4.2% per month and 10.1% per month, respectively (both significant). The pandemic had significant effects on the pattern of poisonings from different agents in Iran, the most important of which were alcohol (ethanol and methanol). These differences had policy implications that can be helpful for policymakers and healthcare systems in combating similar situations in the future.
Topics: Humans; COVID-19; Methanol; Pandemics; Iran; Ethanol; Cannabis; Hallucinogens; Cannabinoid Receptor Agonists
PubMed: 38267612
DOI: 10.1038/s41598-024-52537-y -
Frontiers in Pharmacology 2023The bark of , a Dai medicine in China, has been listed in the Chinese Materia Medica as possessing hemostatic and analgesic properties. Ethnic medicine books record that...
The bark of , a Dai medicine in China, has been listed in the Chinese Materia Medica as possessing hemostatic and analgesic properties. Ethnic medicine books record that its bark or leaves for the treatment of mumps and lymphoma. However, according to the literature survey, anti-inflammatory and analgesic studies available for leaves and branches of have been seldom reported so far. The current study focuses on the metabolites of bark and leaves responsible for anti-inflammatory and analgesic effects on the basis of bioactive-included acetic acid writhing, hot-plate, and xylene-induced ear swelling. The secretion of inflammatory mediators, TNF-, IL-6, IL-1, IL-4, and IL-10, were evaluated for their anti-inflammatory by xylene-induced in mouse ear cells. Histological examination was used to assess the anti-inflammatory and analgesic effects of the branches and leaves of , and Western blot analysis determined the mechanism of the methanolic extract of branches and leaves. Different metabolites of significantly alleviated analgesic and anti-inflammatory effects, with no discernable differences among them. All metabolites decreased the levels of TNF-, IL-1, and IL-6 and increased the levels of IL-4 and IL-10. The analgesic and anti-inflammatory mechanism of the methanolic extract was related to the NF-B signaling pathway. These results not only would account for scientific knowledge for the traditional application of , but also provide a credible theoretical foundation for the further development of anti-inflammatory and analgesic agents.
PubMed: 37829300
DOI: 10.3389/fphar.2023.1249234 -
Journal of Ethnopharmacology Oct 2023Herb-induced liver injury is poorly described for African herbal remedies, such as Acokanthera oppositifolia. Although a commonly used treatment for pain, snake bites...
ETHNOPHARMACOLOGICAL RELEVANCE
Herb-induced liver injury is poorly described for African herbal remedies, such as Acokanthera oppositifolia. Although a commonly used treatment for pain, snake bites and anthrax, it is also a well-known arrow poison, thus toxicity is to be expected.
AIM OF THE STUDY
The cytotoxicity and preliminary mechanisms of toxicity in HepG2 hepatocarcinoma cells were assessed.
MATERIALS AND METHODS
The effect of hot water and methanol extracts were on cell density, oxidative status, mitochondrial membrane potential, fatty acids, caspase-3/7 activity, adenosine triphosphate levels, cell cycling and viability was assessed. Phytochemicals were tentatively identified using ultra-performance liquid chromatography.
RESULTS
The hot water extract displayed an IC of 24.26 μg/mL, and reduced proliferation (S- and G2/M-phase arrest) and viability (by 30.71%) as early as 24 h after incubation. The methanol extract had a comparable IC of 26.16 μg/mL, and arrested cells in the G2/M-phase (by 18.87%) and induced necrosis (by 13.21%). The hot water and methanol extracts depolarised the mitochondrial membrane (up to 0.84- and 0.74-fold), though did not generate reactive oxygen species. The hot water and methanol extracts decreased glutathione (0.42- and 0.62-fold) and adenosine triphosphate (0.08- and 0.26-fold) levels, while fatty acids (2.00- and 4.61-fold) and caspase-3/7 activity (1.98- and 5.82-fold) were increased.
CONCLUSION
Extracts were both cytostatic and cytotoxic in HepG2 cells. Mitochondrial toxicity was evident and contributed to reducing adenosine triphosphate production and fatty acid accumulation. Altered redox status perturbed proliferation and promoted necrosis. Extracts of A. oppositifolia may thus promote necrotic cell death, which poses a risk for inflammatory hepatotoxicity with associated steatosis.
Topics: Humans; Hep G2 Cells; Methanol; Cytostatic Agents; Caspase 3; Plant Extracts; Carcinoma, Hepatocellular; Antineoplastic Agents; Necrosis; Liver Neoplasms; Water; Apocynaceae; Adenosine Triphosphate; Apoptosis
PubMed: 37182674
DOI: 10.1016/j.jep.2023.116617 -
PloS One 2023Pomegranate (Punica granatum) peels have shown numerous health benefits such as antioxidant, anti-inflammatory, and antimicrobial activities. These health activities are...
Pomegranate (Punica granatum) peels have shown numerous health benefits such as antioxidant, anti-inflammatory, and antimicrobial activities. These health activities are owed to the unique phytochemical components present in pomegranate peels. Variations in the pomegranate cultivar, geographical region, and extraction methods significantly affect the phytochemical composition and concentrations of pomegranate fruits and their peels, hence their health outcomes. Therefore, this study aimed to examine the phytochemical contents of pomegranate peels of Jordanian origin and their antioxidant and antimicrobial activities. Among the 6 extracts of pomegranate peels tested, the ethanol extract exhibited the highest total phenolic content (TPC = 297.70 ± 1.73 mg GAE/g DW), highest total flavonoids content (TFC = 116.08 ± 3.46 mg RE/g DW), highest hydrolyzable tannins (HT) contents (688.50 ± 3.54 mg TE/g DW). Whereas the highest condensed tannins (CT) content was found in both the ethanol (13.87 ± 0.58 mg CE/g DW) and methanol (13.84 ± 0.55 mg CE/g DW) extracts. For the antioxidant activities, the water extract of pomegranate peels displayed the highest inhibitory effect on DPPH radicals (9.43 ± 0.06 μmole TE/g DW), while for the ABTS+ assay the methanol and ethanol extracts exhibited the highest activities of 11.09 ± 0.02 and 11.09 ± 0.06 μmole TE/g DW, respectively. For the FRAP assay, the aqueous methanol extract exhibited the highest reducing activity (1.60 ± 0.09 mmole Fe (II)/g DW). As for the antimicrobial activities of various extracts of pomegranate peels, the highest antimicrobial activity against Micrococcus luteus was achieved by the ethanol extract (MIC = 6.25 mg/mL), whereas the lowest antimicrobial activity was observed against Candida krusei using the methanol extract (MIC = 100 mg/mL). These results indicate that pomegranate peels of Jordanian origin are rich in phytochemical content and exhibited strong antioxidant and antimicrobial activities making these agroindustrial by-products potential candidates for various medical applications and possible safe sources for important bioactive components.
Topics: Antioxidants; Fruit; Pomegranate; Plant Extracts; Jordan; Methanol; Phytochemicals; Ethanol; Anti-Infective Agents
PubMed: 38032959
DOI: 10.1371/journal.pone.0295129 -
Biomedicine & Pharmacotherapy =... Dec 2023Mikania cordata (Burm. f.) B.L. Rob. has been traditionally used in tropical countries throughout Asia and Africa to treat gastric ulcers, dyspepsia, and dysentery....
Regulation of anti-inflammatory and antioxidant responses by methanol extract of Mikania cordata (Burm. f.) B. L. Rob. leaves via the inactivation of NF-κB and MAPK signaling pathways and activation of Nrf2 in LPS-induced RAW 264.7 macrophages.
Mikania cordata (Burm. f.) B.L. Rob. has been traditionally used in tropical countries throughout Asia and Africa to treat gastric ulcers, dyspepsia, and dysentery. However, the mechanisms responsible for its anti-inflammatory and antioxidant activities are not fully understood. Therefore, this study sought to investigate the anti-inflammatory and antioxidant effects of methanol extracts of M. cordata (MMC) on inflammation and oxidative stress in lipopolysaccharide (LPS)-stimulated murine RAW 264.7 macrophages and elucidate its underlying regulatory mechanism. MMC significantly suppressed the production of nitric oxide (NO) and prostaglandin E (PGE) in LPS-stimulated RAW 264.7 macrophages by downregulating the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) at both the mRNA and protein levels. Moreover, MMC effectively reduced the mRNA expression levels and production of pro-inflammatory cytokines, including interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α). These suppressive effects of MMC on pro-inflammatory mediators and cytokines were mediated through the inhibition of transforming growth factor beta-activated kinase 1 (TAK1), which subsequently blocked the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs). MMC also upregulated the nuclear factor erythroid-2-related factor 2 (Nrf2) by inducing the degradation of Kelch-like ECH-related protein 1 (Keap1), an Nrf2-specific E3 ligase. Accordingly, MMC enhanced Nrf2 target gene expression of anti-oxidative regulators such as heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO1). However, it had minimal effect on the DPPH radical scavenging capacity in vitro. Collectively, these findings demonstrate that MMC holds promise as a potential therapeutic agent for alleviating inflammation-related diseases and oxidative stress.
Topics: Animals; Mice; Anti-Inflammatory Agents; Antioxidants; Cytokines; Inflammation; Kelch-Like ECH-Associated Protein 1; Lipopolysaccharides; Macrophages; MAP Kinase Signaling System; Methanol; Mikania; NF-E2-Related Factor 2; NF-kappa B; Nitric Oxide Synthase Type II; RAW 264.7 Cells; RNA, Messenger
PubMed: 37864893
DOI: 10.1016/j.biopha.2023.115746 -
The Science of the Total Environment Nov 2023This study analyzes the technical performance, costs and life-cycle greenhouse gas (GHG) emissions of the production of various fuels using air-captured water and CO,...
This study analyzes the technical performance, costs and life-cycle greenhouse gas (GHG) emissions of the production of various fuels using air-captured water and CO, and concentrated solar energy as the source of high-temperature process heat. The solar thermochemical fuel production pathway utilizes a ceria-based redox cycle for splitting water and CO to syngas - a tailored mixture of H and CO - which in turn is further converted to liquid hydrocarbon fuels. The cycle is driven by concentrated solar heat and supplemented by a high-temperature thermal energy storage for round-the-clock continuous operation. The study examines three locations with high direct normal irradiation using a baseline heliostat field reflective area of 1 km for the production of six fuels, i.e. jet fuel and diesel via Fischer-Tropsch, methanol, gasoline via methanol, dimethyl ether, and hydrogen. Two scenarios are considered: near-term future by the year 2030 and long-term future beyond 2030. In the near-term future in Sierra Gorda (Chile), the minimum fuel selling price is estimated at around 76 €/GJ (2.5 €/L) for jet fuel and diesel, 65 €/GJ for methanol, gasoline (via methanol) and dimethyl ether (DME), and 42 €/GJ for hydrogen (excluding liquefaction). In the long-term future, with advancements in solar receiver, redox reactor, high-temperature heat recovery and direct air capture technologies, the industrial-scale plant could achieve a solar-to-fuel efficiency up to 13-19 %, depending on the target fuel, resulting in a minimum fuel selling price of 16-38 €/GJ (0.6-1.3 €/L) for jet fuel and diesel, and 14-32 €/GJ for methanol, gasoline, and DME, making these fuels synthesized from sunlight and air cost-competitive vis-à-vis e-fuels. To produce the same fuels in Tabernas (Spain) and Ouarzazate (Morocco) as in Sierra Gorda, the production cost would increase by 22-33 %. Greenhouse gas savings can be over 80 % already in the near-term future.
PubMed: 37541501
DOI: 10.1016/j.scitotenv.2023.166005 -
Molecular Pharmaceutics Nov 2023The antiparasitic drug niclosamide (NCL) is notable for its ability to crystallize in multiple 1:1 channel solvate forms, none of which are isostructural. Here, using a...
The antiparasitic drug niclosamide (NCL) is notable for its ability to crystallize in multiple 1:1 channel solvate forms, none of which are isostructural. Here, using a combination of time-resolved synchrotron powder X-ray diffraction and thermogravimetry, the process-induced desolvation mechanisms of methanol and acetonitrile solvates are investigated. Structural changes in both solvates follow a complicated molecular-level trajectory characterized by a sudden shift in lattice parameters several degrees below the temperature where the desolvated phase first appears. Model fitting of kinetic data obtained under isothermal heating conditions suggests that the desolvation is rate-limited by the nucleation of the solvent-free product. The desolvation pathways identified in these systems stand in contrast to previous investigations of the NCL channel hydrate, where water loss by diffusion initially yields an anhydrous isomorph that converts to the thermodynamic polymorph at significantly higher temperatures. Taking the view that each solvate lattice is a unique "pre-organized" precursor, a comparison of the pathways from different starting topologies to the same final product provides the opportunity to reevaluate assumptions of how various factors (e.g., solvent binding strength, density) influence solid-state desolvation processes.
Topics: Niclosamide; X-Ray Diffraction; Solvents; Water; Methanol
PubMed: 37850910
DOI: 10.1021/acs.molpharmaceut.3c00481