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1.
J Colloid Interface Sci ; 605: 354-363, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34332409

RESUMO

HYPOTHESIS: Organic co-solvents, which are universally employed in adsorption studies of hydrophobic organic chemicals (HOCs), can inhibit HOC adsorption by competing for active sites on the adsorbent. The adsorbent structure can influence co-solvent interference of HOC adsorption; however, this effect remains unclear, leading to an incomplete understanding of the adsorption mechanism. EXPERIMENTS: In this study, dioctyl phthalate (DOP) was used to investigate competitive adsorption on functionalized graphene sheet in a water-methanol co-solvent system through molecular dynamics simulations and quantum chemical calculations. FINDINGS: The simulations showed that the functional groups in the graphene defects had a strong adsorption affinity for methanol. The adsorbed methanol occupied a large number of active sites at the graphene center, thereby weakening DOP adsorption. However, the methanol adsorbed at the graphene edges could not compete with DOP for the active sites. -COOH had the strongest binding affinity for methanol among the functional groups and thus predominantly controlled the interaction between graphene and methanol. This study makes an innovative contribution toward understanding the competitive adsorption of methanol and DOP on functionalized graphene sheet, especially in visualizing the competition for active sites, and provides theoretical guidance for the removal of HOCs and practical application of graphene.


Assuntos
Dietilexilftalato , Grafite , Adsorção , Metanol , Simulação de Dinâmica Molecular , Solventes
2.
J Environ Manage ; 301: 113927, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34638043

RESUMO

The study demonstrates a two-stage integrated process for bio-methanol production using Methylosinus trichosporium NCIMB 11131, coupled with sequestration of methane and carbon dioxide. The first stage involved generation of methanotrophic biomass via sequestration of methane; which was used as biocatalyst to reduce carbon dioxide into methanol in the second stage. Maximum biomass titer of 3.39 g L-1 and productivity of 0.60 g L-1 d-1 were achieved in semi-batch stirred tank reactor with methane concentration in the inlet gas mixture of 2.5% v/v and gas flow rate of 0.5 vvm. Methane fixation rate was estimated to be 0.32 g L-1 d-1. Maximum methanol titer of 0.58 g L-1 was achieved at headspace carbon dioxide concentration of 50% v/v and liquid to headspace volume ratio 10:90. Subsequently, a kinetic model was developed to predict and understand the system behaviour in terms of dynamic profile of growth, methanol formation, concentration of dissolved methane or carbon dioxide in the aqueous phase and headspace carbon dioxide concentration, in response to varying process parameters. The model can serve as a tool for estimation of process parameters and aid in overall production optimization.


Assuntos
Metano , Methylosinus trichosporium , Biomassa , Dióxido de Carbono , Metanol
3.
Food Chem ; 372: 131272, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34628121

RESUMO

Bioactive compounds from strawberries have been associated with multiple healthy benefits. The present study aimed to assess chemical characterization of a methanolic extract of the Romina strawberry variety in terms of antioxidant capacity, polyphenols profile and chemical elements content. Additionally, potential toxicity, the effect on amyloid-ß production and oxidative stress of the extract was in vivo evaluated in the experimental model Caenorhabditis elegans. Results revealed an important content in phenolic compounds (mainly ellagic acid and pelargonidin-3-glucoside) and minerals (K, Mg, P and Ca). The treatment with 100, 500 or 1000 µg/mL of strawberry extract did not show toxicity. On the contrary, the extract was able to delay amyloid ß-protein induced paralysis, reduced amyloid-ß aggregation and prevented oxidative stress. The potential molecular mechanisms present behind the observed results explored by RNAi technology revealed that DAF-16/FOXO and SKN-1/NRF2 signaling pathways were, at least partially, involved.


Assuntos
Doença de Alzheimer , Proteínas de Caenorhabditis elegans , Fragaria , Peptídeos beta-Amiloides/genética , Animais , Antioxidantes , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Fragaria/genética , Fragaria/metabolismo , Metanol , Estresse Oxidativo , Extratos Vegetais , Fatores de Transcrição/metabolismo
4.
Sci Total Environ ; 804: 150236, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34520913

RESUMO

Renewable energy sources for harnessing biofuels are the viable solution to substitute fossil fuels and reduce production cost. In this study, waste cooking oil was converted into biodiesel via a customized solar reactor. The solar reactor was customized using copper tubes and black surface to trap solar energy for conversion of waste cooking oil into biodiesel. The main experimental parameters studied are temperature (30 to 50 °C), stirring speed (100 to 500 rpm), catalyst loading (0.25 to 1.25 wt%), flow rate (3 to 15 LPH), and methanol to oil ratio (3:1 to 15:1), respectively. The uppermost conversion of 82% was achieved at catalyst load of 0.75 wt%, stirring speed of 300 rpm, flow rate of 3 LPH and methanol/oil ratio of 12:1. Performance of biodiesel blend (D80 + BD20) in CI engine showed a decrease in ignition delay (10.5 deg. CA) and brake thermal efficiency (32.7%) at maximum load (100%). Smoke emission was also decreased with an increase in biodiesel blend at lower brake power, but an increase in brake power increased the smoke emission.


Assuntos
Biocombustíveis , Culinária , Biocombustíveis/análise , Catálise , Metanol , Óleos Vegetais , Emissões de Veículos
5.
J Sci Food Agric ; 102(1): 425-433, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34143901

RESUMO

BACKGROUND: Apple wine is a popular alcoholic beverage for its nutrition and fresh taste. However, the methanol existing in apple wine restricts its quality. Unfortunately, there are no methods to reduce the methanol content in fruit wine. To this end, bentonite (B), calcium chloride (CC) and their combination (B&CC) were added into apple juice in this study. The treated juice (0) and supernatant obtained by standing the juice at 25 °C for 24 h were fermented at 25 °C and 10 °C, respectively. RESULTS: Bentonite was an excellent methanol interrupter, a pectin retainer and a wine quality defender both at 25 and 10 °C. The lowest methanol content of 1.41 mg L-1 and higher pectin content of 84.74 mg L-1 were reached in the finished wine by B0 at 10 °C. Calcium chloride decreased pectin content, elevated methanol content and changed the profile of individual organic acids. In fact, the wine by B&CC0 at 25 °C showed dramatic changes in individual organic acids. The content of l-malic acid and succinic acid was only 2.22% and 6.29% of the control, respectively, while the lactic acid content was 17.72 times that of the control. CONCLUSIONS: It is suggested that B0 and fermented at 10 °C was the most effective way to decrease methanol content, retain pectin content and defend wine quality. © 2021 Society of Chemical Industry.


Assuntos
Bebidas Alcoólicas/análise , Bentonita/química , Cloreto de Cálcio/química , Manipulação de Alimentos/métodos , Malus/química , Fermentação , Manipulação de Alimentos/instrumentação , Frutas/química , Metanol/química , Pectinas/química
6.
Talanta ; 237: 122888, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34736708

RESUMO

In this work, based on the dual catalytic properties of copper (Cu) particles for methanol oxidation and persulfate initiated radical polymerization, a temperature-controlled catalytic electrode, defined the PNIPAM-Cu@CP, was constructed by electrodepositing Cu particles on a carbon paper electrode and triggering the polymerization of the temperature-sensitive polymer N-isopropylacrylamide (PNIPAM) on the surface of the electrode, which is expected to be applicated in the micro-direct methanol fuel cell (DMAC) for detection of methanol crossover and also has temperature recognition and high-temperature self-protection functions. Cu particles and PNIPAM were characterized by X-ray diffraction (XRD), fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) for their specific structure and morphology. The cyclic voltammetry (CV) results showed the proposed electrode as a temperature-controlled switch-like methanol sensor, has a wide linear range (1-300 mM and 300-1200 mM), excellent sensitivity (72.8 µA cm-2 mM-1 and 11.5 µA cm-2 mM-1) and a low detection limit of 0.3 mM for methanol. In addition, the sensor also has excellent selectivity and temperature-triggered switchable electrocatalytic activity. The efficient and simple preparation method of the electrode is expected to be used in the development of a methanol sensor for real-time methanol detection in micro-DMAC.


Assuntos
Cobre , Metanol , Catálise , Técnicas Eletroquímicas , Eletrodos , Limite de Detecção , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
7.
Braz J Biol ; 83: e243332, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34730611

RESUMO

The present study was aimed to manifest the antibacterial and antifungal activity of methanolic extracts of Salix alba L. against seven Gram-positive and Gram-negative bacterial pathogens e.g. Streptococcus pyogenes, Staphylococcus aureus (1), S. aureus (2), Shigella sonnei, Escherichia coli (1), E. coli (2) and Neisseria gonorrhoeae and three fungal isolates from the air such as Aspergillus terreus, A. ornatus, and Rhizopus stolonifer. Two different serotypes of S. aureus and E. coli were used. The agar well-diffusion method results showed the dose-dependent response of plant extracts against bacterial and fungal strains while some organisms were found resistant e.g. E. coli (1), S. sonnei, A. terreus and R. stolonifer. The highest antibacterial activity was recorded at 17.000±1.732 mm from 100 mg/mL of leaves methanolic extracts against S. pyogenes while the activity of most of the pathogens decreased after 24 h of incubation. The highest antifungal activity was reported at 11.833±1.0 mm against A. ornatus at 50 mg/mL after 48 h of the incubation period. These experimental findings endorse the use of S. alba in ethnopharmacological formulations and suggest the use of methanolic extracts of the said plant to develop drugs to control the proliferation of resistant disease causing pathogenic microbes.


Assuntos
Antifúngicos , Salix , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Aspergillus , Escherichia coli , Metanol , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologia , Rhizopus , Staphylococcus aureus
8.
Appl Microbiol Biotechnol ; 105(23): 8761-8769, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34748038

RESUMO

Promoters play an important role in regulating gene expression, and construction of microbial cell factories requires multiple promoters for balancing the metabolic pathways. However, there are only a limited number of characterized promoters for gene expression in the methylotrophic yeast Ogataea polymorpha, which hampers the extensive harnessing of this important yeast toward a cell factory. Here we characterized the promoters of methanol utilization pathway, precursor supply pathway, and reactive oxygen species (ROS) defense system, by using a green fluorescence protein variant (GFPUV) as a quantification signal. Finally, the characterized promoters were used for tuning a fatty alcohol biosynthetic pathway in O. polymorpha and realized fatty alcohol production from methanol. This promoter box should be helpful for gene expression and pathway optimization in the methylotrophic yeast O. polymorpha. KEY POINTS : • 22 promoters related to methanol metabolism were characterized in O. polymorpha. • Promoter truncation resulted shorter and compact promoters. • Promoters with various strengths were used for regulating a fatty alcohol biosynthesis from methanol.


Assuntos
Engenharia Metabólica , Metanol , Pichia/genética , Regiões Promotoras Genéticas , Saccharomycetales
9.
Chin J Physiol ; 64(5): 232-243, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34708715

RESUMO

Macrophages are essential for host defense as they control foreign pathogens and induce acquired immune responses. Activated macrophages secrete pro-inflammatory reactive substances causing local cell and tissue inflammatory response, which helps an organism resist the invasion of foreign pathogens. Excessive or chronic inflammation can cause several diseases. Previous studies have reported that vinegar treatment decreases the levels of several inflammatory cytokines and biomarkers, including mitogen-activated protein kinases, cyclooxygenase-2, inducible nitric oxide synthase (iNOS), and nitric oxide (NO). However, the benefits of wood vinegar produced from Griffith's ash (Fraxinus formosana Hayata) in reducing inflammation have not been investigated yet. Thus, assuming that wood vinegar exerts anti-inflammatory effects in macrophages, in this study, we investigated the potential anti-inflammatory effects of the wood vinegar from Griffith's ash using a lipopolysaccharide (LPS)-induced inflammatory response model in RAW264.7 macrophages. We showed that the wood vinegar inhibited the production of iNOS, NO, and interleukin 6. In addition, we found that the wood vinegar reduced the phosphorylation levels of p38 and protein kinase C-α/δ in the LPS-stimulated RAW264.7 macrophages. Based on these results, we suggest that the produced wood vinegar can reduce inflammation in LPS-activated macrophages.


Assuntos
Ácido Acético , Anti-Inflamatórios , Macrófagos/efeitos dos fármacos , Ácido Acético/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Ciclo-Oxigenase 2 , Fraxinus , Inflamação/tratamento farmacológico , Mediadores da Inflamação , Lipopolissacarídeos , Metanol , Camundongos , NF-kappa B/metabolismo , Óxido Nítrico , Óxido Nítrico Sintase Tipo II , Células RAW 264.7
10.
J Chromatogr A ; 1657: 462583, 2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34624711

RESUMO

Counter-current chromatography (CCC) is a widely used liquid-liquid separation technique. Much work has been performed to improve the retention of stationary phases and throughput. In previous research, high aspect ratio rectangular horizontal (RH) tubing has been proven to be able to improve resolution and throughput in comparison with standard circular (SC) tubing. However, those modifications and improvements of tubing shapes have only been tested on analytical tubing thus far. This study aims to verify whether RH tubing could achieve similar high stationary phase retention (Sf) and throughput on a semi-preparative CCC apparatus. First, a lighter and larger volume semi-preparative bobbin with thin-wall RH tubing was successfully manufactured. Then the Sf of this bobbin was tested with n-hexane-ethyl acetate-methanol-water (HEMWat) and dichloromethane-methanol-water (DMW) solvent systems, and its maximum throughput was explored with the mixture of Magnolia officinalis Rehd. Et Wils. The results show that the thin-wall RH tubing bobbin can retain high Sf for these solvent systems, even at a relatively high mobile phase flow rate, which is consistent with the analytical bobbin results. The throughput test demonstrates that 2.12 × throughput can be obtained with the RH tubing column bobbin compared to the conventional SC tubing column bobbin without changing the outside dimensions of the bobbin. The present study is a necessary step for the application of the RH tubing bobbin from a laboratory analytical scale to preparative industrial scale.


Assuntos
Distribuição Contracorrente , Magnolia , Cromatografia Líquida de Alta Pressão , Metanol , Solventes , Água
11.
Phytomedicine ; 93: 153771, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34700271

RESUMO

BACKGROUND: Moringa oleifera Lam (MO) is native to India and is a cash crop widely cultivated in tropical and sub-tropical areas. The health improving properties of MO has been studied from a long time ago for the numerous phenolic compounds, including vitamins, flavonoids, phenolic acids, isothiocyanates, tannins and saponins, which are present in considerable amounts in the plant. A growing spectrum of therapeutic characteristics of MO leaves has been found and used in the remission or treatment of oxidative stress, liver disease, neurological disease, hyperglycemia and cancer. HYPOTHESIS: This review focused on researches applying MO or MO leaf extract as a functional food or cure against various disease and cellular injuries. We believed it would help the discovery of therapeutic application of MO and understanding of MO phytochemistry. METHODS: The data collected in this review were extracted from researches indexed in Web of Science, google scholar, PubMed, Science Direct and Scopus to find out health benefits and biological activities of MO leaves polyphenols. The studies reporting mechanistic route of phenolic compounds of MO leaves were also considered in the present study. RESULTS: It has been reported that polyphenols of MO leaf have protective characteristics against neurodegenerative disorders through reducing DNA damage, activation of AchE activity and inhibition of caspase-3 activity. It has been reported that, they protected the kidney from damage caused by melamine through suppressed the pro-inflammatory cytokine, metallopeptidase inhibitor 1 (TIMP-1), and kidney injury molecule 1 (KIM-1). Similarly, methanol extract of MO leaves has low hypoglycemic attributes and attenuate the risk of diabetes caused by alloxan by enhancing lipid metabolism and stimulating insulin release, glucose uptake, and glycogen synthesis. In addition, MO leaves are becoming the best phytomedicine to reduce hypertension, which are naturally known as angiotensin-1converting enzyme (ACE), acetylcholinesterase, arginase and phosphodiesterase 5 (PDE5) inhibitors. CONCLUSION: MO leaves extract as a health promoting food additives for human and animals due to its great protective effect against many diseases and the widely persistent environmental toxins which disrupted cellular metabolic function. More studies are required to use the phenolic compounds of MO leaves to develop and produce drugs for controlling and treatment of various diseases.


Assuntos
Moringa oleifera , Acetilcolinesterase , Animais , Antioxidantes/farmacologia , Humanos , Metanol , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Folhas de Planta
12.
J Chromatogr A ; 1657: 462586, 2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34689906

RESUMO

Coumarin is a phytotoxin found in the popular spice cinnamon, which is used to flavor many Asian curry dishes. In this work, we developed and compared the analytical performance of reversed-phase liquid chromatography (RP-LC) and sweeping-micellar electrokinetic chromatography (MEKC) methods for the determination of coumarin in complex curry (gravy) samples. Using a matrix matched sample (curry after solvent extraction with methanol and diluted with 100 mM phosphoric acid), the intra-day and inter-day repeatability of retention/migration time and (corrected) peak area for both methods were acceptable (%RSD (n=6) ≤ 5%). The linear range and limit of quantitation (LOQ) were an order of magnitude better in RP-LC (RP-LC linear range = 0.11-108 mg/kg, LOQ = 0.11 mg/kg) (Sweeping-MEKC linear range = 2.16-216 mg/kg, LOQ = 2.16 mg/kg). However, the limit of detection (S/N=3) and LOQ in sweeping-MEKC was 0.65 mg/kg and 2.16 mg/kg, which were sufficient to report the levels of coumarin ≥ the European limit of 2 mg/kg in foods. During the analysis of 25 curry samples, relatively similar results for sweeping-MEKC and RP-LC were obtained for 6 samples that contained coumarin >LOQ of sweeping-MEKC. Interferences in RP-LC lead to significant overestimation of coumarin levels in 3 samples. Coumarin levels above the EU limit was found in 6 curry samples using the more selective sweeping-MEKC. This work should also raise public awareness on the presence of potentially high levels of coumarin in some foods.


Assuntos
Cromatografia Capilar Eletrocinética Micelar , Cromatografia de Fase Reversa , Cumarínicos , Metanol , Micelas
13.
J Chromatogr A ; 1658: 462631, 2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34700137

RESUMO

A method to analyse short-chain bioactive peptides (MW < 800 Da) and their impurities was developed with a unified chromatography (UC) analysis, including a wide mobile phase gradient ranging from supercritical fluid to near-liquid conditions, with UV and electrospray ionization mass spectrometry detection (ESI-MS). Four stationary phases and three mobile phase compositions were examined. Ten model peptides were first selected to identify the best operating conditions, including five linear tripeptides and five cyclic pentapeptides, with log P values ranging from -5.9 to 3.6, and including isomeric species. Derringer desirability functions were designed to identify optimal operating conditions based on 7 criteria, namely the number of peaks detected (including all impurities resolved), the proportion of the chromatogram occupied by target peaks, the least favourable resolution observed between the main peptide and impurities, peak shape features (asymmetry and peak width at half height), and finally the signal-to-noise ratio observed both with UV (210 nm) and ESI-MS in positive ionization mode. The optimum conditions were obtained on Ascentis Express OH5 stationary phase, with a mobile phase composed of carbon dioxide and methanol, comprising 2% water and 20 mM ammonium hydroxide. The final gradient program ranged from 5 to 80% co-solvent in CO2, with a reversed flow rate gradient ranging from 3.0 to 1.5 mL/min. Back-pressure was set at 120 bar and the column oven temperature at 60°C. Optimal conditions were applied to a large set of 76 peptides (34 linear tripeptides and 42 cyclic pentapeptides) and provided adequate scattering of the peaks in the retention space, together with some separation of isomeric species, particularly for the cyclic peptides.


Assuntos
Cromatografia com Fluido Supercrítico , Espectrometria de Massas por Ionização por Electrospray , Metanol , Peptídeos , Solventes
14.
Toxicon ; 203: 40-50, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34610271

RESUMO

Moringa stenopetala (Baker f.) Cuf.and other Moringa species have traditionally been used to treat various diseases. The purpose of this study was to determine the cytotoxic and genotoxic effects of the methanolic extract of M. stenopetala leaf and its fractions on selected tumor cells. Cytotoxicity was determined by MTT assay. The comet assay was used toassess DNA damage, and gel electrophoresis was used to determine DNA fragmentation. Gene expression was analyzed by qPCR using two specific genes for each cancer cell line. Fractionation of the methanolic extract (E-1) on Diaion HP-20 yielded five fractions (Fr-2 to Fr-6); only Fr-4 and Fr-6 were cytotoxic to breast cancer cells (MCF-7; IC50 = 58.3 ± 0.93 and 35.8 ± 2.44 µg/mL, respectively), human hepatocellular carcinoma cells (HepG2; IC50 = 57.8 ± 1.57 and 39.3 ± 1.90 µg/mL, respectively), and Fr-4 was cytotoxic to human colon cancer cells (HCT-116; IC50 = 94.2 ± 4.9 µg/mL). In addition, exposure of the cancer cells to Fr-4 and Fr-6 resulted in a high level of DNA damage. Moreover, relative expression of MTAP and CDKN2A in MCF-7 were increased, whereas expression of p21 and p53 in HCT-116, and APC and TERT in HepG2 were decreased, similar to that of doxorubicin. LC-qTOF-MS was used to identify metabolites in E-1, the majority of which were enriched in Fr-4. Two terpenes (loliolide and dihydroactinidiolide), the majority of the flavonoids, and niazirin were about two fold enriched in Fr-4, whereas the majority of the lipids were 4-10 fold enriched. However, Fr-6 hardly showed compounds other than the two terpenes that were enriched 1.5 and 7 fold. The findings suggest that Fr-4 and Fr-6 are promising sources of compounds possessing cytotoxic and genotoxic properties.


Assuntos
Moringa , Dano ao DNA , Expressão Gênica , Humanos , Metaboloma , Metanol , Extratos Vegetais/farmacologia , Folhas de Planta
15.
Sensors (Basel) ; 21(18)2021 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-34577485

RESUMO

Handheld Raman and portable FT-IR spectroscopy devices were evaluated for fast and non-invasive determination of methanol and ethanol levels in Peruvian Pisco. Commercial Peruvian Pisco (n = 171) samples were kindly provided by the UNALM Alliance for Research in Alcohol and its Derivatives (Lima, Peru) and supplemented by purchases at grocery and online stores. Pisco spectra were collected on handheld Raman spectrometers equipped with either a 1064 nm or a 785 nm excitation laser and a portable infrared unit operating in transmission mode. The alcohol levels were determined by GC-MS. Calibration models used partial least-squares regression (PLSR) to develop prediction algorithms. GC-MS data revealed that 10% of Pisco samples had ethanol levels lower than 38%, indicating possible water dilution. Methanol levels ranged from 10 to 130 mg/100 mL, well below the maximum levels allowed for fruit brandies. Handheld Raman equipped with a 1064 nm excitation laser gave the best results for determining ethanol (SEP = 1.2%; RPre = 0.95) and methanol (SEP = 1.8 mg/100 mL; RPre = 0.93). Randomly selected Pisco samples were spiked with methanol (75 to 2800 mg/100 mL), and their Raman spectra were collected through their genuine commercial bottles. The prediction models gave an excellent performance (SEP = 98 mg/100 mL; RPre = 0.97), allowing for the non-destructive and non-contact determination of methanol and ethanol concentrations without opening the bottles.


Assuntos
Metanol , Vitis , Etanol , Espectroscopia de Infravermelho com Transformada de Fourier , Vibração
16.
Anal Chem ; 93(38): 12987-12994, 2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34520172

RESUMO

Process analysis of heterogeneous catalytic reactions such as lignin depolymerization is essential to understand the reaction mechanism at the molecular level, but it is always challenging due to harsh conditions. Herein, we report an operando process analysis strategy by combining a microbatch reactor with high-resolution mass spectrometry (MS) via a reactor-integrated electrospray ionization (R-ESI) technique. R-ESI-MS expands the applications of traditional in situ MS to a heterogeneous and high-pressure liquid-phase system. With this strategy, we present the evolution of a series of monomers, dimers, and oligomers during lignin depolymerization under operando conditions (methanol solvent, 260 °C, ∼8 MPa), which is the first experimental elucidation of a progressive depolymerization pathway and evidence of repolymerization of active monomers. The proposed R-ESI-MS is crucial in probing depolymerization intermediates of lignin; it also provides a flexible strategy for process analysis of heterogeneous catalytic reactions under operando conditions.


Assuntos
Lignina , Espectrometria de Massas por Ionização por Electrospray , Catálise , Metanol , Solventes
17.
Int J Mol Sci ; 22(17)2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34502095

RESUMO

Sphingosine-1-phosphate (S1P) synthesized by sphingosine kinase (SPHK) is a signaling molecule, involved in cell proliferation, growth, differentiation, and survival. Indeed, a sharp increase of S1P is linked to a pathological outcome with inflammation, cancer metastasis, or angiogenesis, etc. In this regard, SPHK/S1P axis regulation has been a specific issue in the anticancer strategy to turn accumulated sphingosine (SPN) into cytotoxic ceramides (Cers). For these purposes, there have been numerous chemicals synthesized for SPHK inhibition. In this study, we investigated the comparative efficiency of dansylated PF-543 (DPF-543) on the Cers synthesis along with PF-543. DPF-543 deserved attention in strong cytotoxicity, due to the cytotoxic Cers accumulation by ceramide synthase (CerSs). DPF-543 exhibited dual actions on Cers synthesis by enhancing serine palmitoyltransferase (SPT) activity, and by inhibiting SPHKs, which eventually induced an unusual environment with a high amount of 3-ketosphinganine and sphinganine (SPA). SPA in turn was consumed to synthesize Cers via de novo pathway. Interestingly, PF-543 increased only the SPN level, but not for SPA. In addition, DPF-543 mildly activates acid sphingomyelinase (aSMase), which contributes a partial increase in Cers. Collectively, a dansyl-modified DPF-543 relatively enhanced Cers accumulation via de novo pathway which was not observed in PF-543. Our results demonstrated that the structural modification on SPHK inhibitors is still an attractive anticancer strategy by regulating sphingolipid metabolism.


Assuntos
Ceramidas/biossíntese , Inibidores Enzimáticos/farmacologia , Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Pirrolidinas/química , Sulfonas/química , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Compostos de Dansil/química , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/toxicidade , Humanos , Metanol/química , Esfingosina/metabolismo , Especificidade por Substrato , Suínos
18.
Int J Mol Sci ; 22(18)2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34575954

RESUMO

The halogen elimination of 1,2-diiodoethane (C2H4I2) and 1,2-diiodotetrafluoroethane (C2F4I2) serves as a model reaction for investigating the influence of fluorination on reaction dynamics and solute-solvent interactions in solution-phase reactions. While the kinetics and reaction pathways of the halogen elimination reaction of C2H4I2 were reported to vary substantially depending on the solvent, the solvent effects on the photodissociation of C2F4I2 remain to be explored, as its reaction dynamics have only been studied in methanol. Here, to investigate the solvent dependence, we conducted a time-resolved X-ray liquidography (TRXL) experiment on C2F4I2 in cyclohexane. The data revealed that (ⅰ) the solvent dependence of the photoreaction of C2F4I2 is not as strong as that observed for C2H4I2, and (ⅱ) the nongeminate recombination leading to the formation of I2 is slower in cyclohexane than in methanol. We also show that the molecular structures of the relevant species determined from the structural analysis of TRXL data provide an excellent benchmark for DFT calculations, especially for investigating the relevance of exchange-correlation functionals used for the structural optimization of haloalkanes. This study demonstrates that TRXL is a powerful technique to study solvent dependence in the solution phase.


Assuntos
Cicloexanos/química , Hidrocarbonetos Halogenados/química , Soluções/química , Termodinâmica , Halogênios/química , Cinética , Metanol/química , Estrutura Molecular , Radiografia , Solventes/química , Difração de Raios X
19.
J Environ Manage ; 299: 113592, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34479149

RESUMO

Acid-base bifunctional heterogeneous solid catalysts, known as the active site with base-acid properties, exhibited relatively good performance on the transesterification for soybean oil for green fuel production. We investigated the use of niobium and three alkali metal oxides (Li, Na, and K) as MyNbOX (M = Li, Na, K) composite as acid-base catalysts for biodiesel production. MyNbOX catalysts were prepared using a simple solid-state reaction, mixing, and grinding niobium dioxide with alkali metal carbonates calcined at 800 °C in air for 4 h. XRD, BET, FE-SEM, TEM and TPD techniques were employed for catalysts characterization. The highest biodiesel yield (98.08%) was achieved under the transesterification condition of 65 °C, 6 h, 24 methanol/oil molar ratio and 2 wt% of LiNbO3 as the catalyst. The results showed that LiNbO3 could be efficiently reused at least 10 cycles with an insignificant reduction in the biodiesel yield. The physicochemical properties of the biodiesel were further studied and compared with the ASTM and the EN biodiesel specifications. The results showed that the properties of the biodiesel produced complied with the international standard specifications.


Assuntos
Biocombustíveis , Óleo de Soja , Catálise , Esterificação , Metanol
20.
Arch Microbiol ; 203(9): 5715-5721, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34476514

RESUMO

A novel methylotrophic bacterium, strain Zm11T, was isolated from reddish brown snow collected in a moor in Japan. Cells of the isolate were Gram-stain-negative, motile, and rod-shaped (0.6-0.7 × 1.2-2.7 µm). Growth was observed at 5-32 °C with an optimum growth temperature of 25-28 °C. The pH range for growth was 5.4-7.8 with an optimum pH of 6.8. The strain utilized only methanol as carbon and energy sources for aerobic growth. The major cellular fatty acids (> 40% of total) were summed feature 3 (C16:1ω7c and/or C16:1ω6c) and C16: 0. The predominant quinone was Q-8, and major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The complete genome of strain Zm11T is composed of a circular chromosome (2,800,413 bp), with G + C content of 46.4 mol%. Phylogenetic analyses were conducted based on the 16S rRNA gene sequence and conserved proteins encoded in the genome. The results of analyses indicate that strain Zm11T is a member of the family Methylophilaceae but does not belong to any existing genus. On the basis of its genomic and phenotypic properties, strain Zm11T (= DSM111909T = NBRC114766T) is proposed as the type strain of a new species in a new genus, Methyloradius palustris gen. nov., sp. nov.


Assuntos
Metanol , Neve , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/análise , Oxirredução , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona
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