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Drug Testing and Analysis Jun 2022Although substances incorporated by ingestion are strongly bound to hair, their loss may occur if aggressive decontamination procedures are applied, especially in highly...
Although substances incorporated by ingestion are strongly bound to hair, their loss may occur if aggressive decontamination procedures are applied, especially in highly damaged/porous hair. Evaluation of cleaning procedures using hair samples with different porosity obtained from ethanol or drug users (cocaine, heroin, methamphetamine, methadone, fentanyl, tramadol, diazepam, buprenorphine, dihydrocodeine, citalopram and trazodone). The effect of washing time and multiple wash steps with water and methanol were evaluated. Hair samples (n = 16) were selected and evaluated according to (a) the drug pattern consumption, (b) available amount, and (c) hair porosity (c1 'cosmetic treatment', c2: storage time). Six of them were soaked with an aqueous deuterated analogue solution. The samples were cut in 1-cm segments and homogenized. All hair samples were then decontaminated one or six times with 1.5 ml of water or methanol during 1, 5, 15, 30, 60 and/or 90 min (n = 1 to 3/sample, depending on the available amount of hair). Hair extracts were then cleaned up via a solid-phase extraction (SPE) or liquid-liquid extraction (LLE), while the washes were evaporated to dryness. All were thereafter reconstituted and analysed with routine ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) methods. Although concentrations of parent drugs and/or metabolites presented a negative trend along the washing time with methanol (up to 80%), the compounds were relatively well retained in hair even after a 90 min wash (with methanol or water) in most samples, and their retention would depend mostly on the hair nature rather than their physicochemical properties (whether incorporated by ingestion and/or from external contamination). Moreover, parent drugs and/or metabolites were detected in the washes in most samples, and the ratio between hair and washes decreased along the washing time. More than 50% of the deuterated analogues soaked into hair were still present after the different washing steps. Losses were observed more frequently for long-term stored hair samples, after decontamination with methanol for more than 30 min. Therefore, prolonged or repeated cleaning with methanol should be avoided in general procedures.
Topics: Chromatography, Liquid; Decontamination; Hair; Methanol; Substance Abuse Detection; Tandem Mass Spectrometry; Water
PubMed: 35148467
DOI: 10.1002/dta.3237 -
Molecules (Basel, Switzerland) Oct 2022Biodiesel is generally produced from vegetable oils and methanol, which also generates glycerol as byproduct. To improve the overall economic performance of the process,...
Biodiesel is generally produced from vegetable oils and methanol, which also generates glycerol as byproduct. To improve the overall economic performance of the process, the selective formation of methanol from glycerol is important in biodiesel production. In the present study, a CaO modified HZSM-5 zeolite was prepared by an impregnation method and used for the conversion of glycerol to methanol. We found that the 10%CaO/HZSM-5 with Si/Al ratio of 38 exhibited highest selectivity to methanol of 70%, with a glycerol conversion of 100% under 340 ℃ and atmospheric pressure. The characterization results showed that the introduction of a small amount of CaO into the HZSM-5 did not affect the structure of zeolite. The incorporation of HZSM-5 as an acidic catalyst and CaO as a basic catalyst in a synergistic catalysis system led to higher conversion of glycerol and selectivity of methanol.
Topics: Zeolites; Methanol; Biofuels; Glycerol; Catalysis
PubMed: 36364049
DOI: 10.3390/molecules27217221 -
Analytical Chemistry Jan 2021Methanol poisoning outbreaks after consumption of adulterated alcohol frequently overwhelm health care facilities in developing countries. Here, we present how a...
Methanol poisoning outbreaks after consumption of adulterated alcohol frequently overwhelm health care facilities in developing countries. Here, we present how a recently developed low-cost and handheld breath detector can serve as a noninvasive and rapid diagnostic tool for methanol poisoning. The detector combines a separation column and a micromachined chemoresistive gas sensor fully integrated into a device that communicates wirelessly with a smartphone. The performance of the detector is validated with methanol-spiked breath of 20 volunteers (105 breath samples) after consumption of alcoholic beverages. Breath methanol concentrations were quantified accurately within 2 min in the full breath-relevant range (10-1000 ppm) in excellent agreement ( = 0.966) with benchtop mass spectrometry. Bland-Altman analysis revealed sufficient limits of agreement (95% confidence intervals), promising to indicate reliably the clinical need for antidote and hemodialysis treatment. This simple-in-use detector features high diagnostic capability for accurate measurement of methanol in spiked breath, promising for rapid screening of methanol poisoning and assessment of severity. It can be applied readily by first responders to distinguish methanol from ethanol poisoning and monitor in real time the subsequent hospital treatment.
Topics: Breath Tests; Humans; Methanol; Spectroscopy, Fourier Transform Infrared
PubMed: 33315383
DOI: 10.1021/acs.analchem.0c04230 -
Communications Biology May 2020Synthetic methylotrophy has recently been intensively studied to achieve methanol-based biomanufacturing of fuels and chemicals. However, attempts to engineer platform...
Synthetic methylotrophy has recently been intensively studied to achieve methanol-based biomanufacturing of fuels and chemicals. However, attempts to engineer platform microorganisms to utilize methanol mainly focus on enzyme and pathway engineering. Herein, we enhanced methanol bioconversion of synthetic methylotrophs by improving cellular tolerance to methanol. A previously engineered methanol-dependent Corynebacterium glutamicum is subjected to adaptive laboratory evolution with elevated methanol content. Unexpectedly, the evolved strain not only tolerates higher concentrations of methanol but also shows improved growth and methanol utilization. Transcriptome analysis suggests increased methanol concentrations rebalance methylotrophic metabolism by down-regulating glycolysis and up-regulating amino acid biosynthesis, oxidative phosphorylation, ribosome biosynthesis, and parts of TCA cycle. Mutations in the O-acetyl-L-homoserine sulfhydrylase Cgl0653 catalyzing formation of L-methionine analog from methanol and methanol-induced membrane-bound transporter Cgl0833 are proven crucial for methanol tolerance. This study demonstrates the importance of tolerance engineering in developing superior synthetic methylotrophs.
Topics: Corynebacterium glutamicum; Evolution, Molecular; Industrial Microbiology; Laboratories; Metabolic Engineering; Methanol
PubMed: 32382107
DOI: 10.1038/s42003-020-0954-9 -
Molecules (Basel, Switzerland) Aug 2022Dimethyl carbonate is a generally used chemical substance which is environmentally sustainable in nature and used in a range of industrial applications as intermediate.... (Review)
Review
Dimethyl carbonate is a generally used chemical substance which is environmentally sustainable in nature and used in a range of industrial applications as intermediate. Although various methods, including methanol phosgenation, transesterification and oxidative carbonylation of methanol, have been developed for large-scale industrial production of DMC, they are expensive, unsafe and use noxious raw materials. Green production of DMC from CO and methanol is the most appropriate and eco-friendly method. Numerous catalysts were studied and tested in this regard. The issues of low yield and difficulty in tests have not been resolved fundamentally, which is caused by the inherent problems of the synthetic pathway and limitations imposed by thermodynamics. Electron-assisted activation of CO and membrane reactors which can separate products in real-time giving a maximum yield of DMC are also being used in the quest to find more effective production method. In this review paper, we deeply addressed green production methods of DMC using Zr/Ce/Cu-based nanocomposites as catalysts. Moreover, the relationship between the structure and activity of catalysts, catalytic mechanisms, molecular activation and active sites identification of catalysts are also discussed.
Topics: Carbon Dioxide; Formates; Methanol; Oxides
PubMed: 36080185
DOI: 10.3390/molecules27175417 -
Acta Biochimica Et Biophysica Sinica Apr 2022Hyperglycemia in diabetic patients is associated with abnormally-elevated cellular glucose levels. It is hypothesized that increased cellular glucose will lead to...
Hyperglycemia in diabetic patients is associated with abnormally-elevated cellular glucose levels. It is hypothesized that increased cellular glucose will lead to increased formation of endogenous methanol and/or formaldehyde, both of which are then metabolically converted to formic acid. These one-carbon metabolites are known to be present naturally in humans, and their levels are increased under diabetic conditions. Mechanistically, while formaldehyde is a cross-linking agent capable of causing extensive cytotoxicity, formic acid is an inhibitor of mitochondrial cytochrome oxidase, capable of inducing histotoxic hypoxia, ATP deficiency and cytotoxicity. Chronic increase in the production and accumulation of these toxic one-carbon metabolites in diabetic patients can drive the pathogenesis of ocular as well as other diabetic complications. This hypothesis is supported by a large body of experimental and clinical observations scattered in the literature. For instance, methanol is known to have organ- and species-selective toxicities, including the characteristic ocular lesions commonly seen in humans and non-human primates, but not in rodents. Similarly, some of the diabetic complications (such as ocular lesions) also have a characteristic species-selective pattern, closely resembling methanol intoxication. Moreover, while alcohol consumption or combined use of folic acid plus vitamin B is beneficial for mitigating acute methanol toxicity in humans, their use also improves the outcomes of diabetic complications. In addition, there is also a large body of evidence from biochemical and cellular studies. Together, there is considerable experimental support for the proposed hypothesis that increased metabolic formation of toxic one-carbon metabolites in diabetic patients contributes importantly to the development of various clinical complications.
Topics: Animals; Carbon; Diabetes Mellitus; Diabetic Retinopathy; Formaldehyde; Formates; Glucose; Humans; Methanol
PubMed: 35607958
DOI: 10.3724/abbs.2022012 -
Analytical Chemistry Sep 2022A key element of successful lipidomics analysis is a sufficient extraction of lipid molecules typically by two-phase systems such as chloroform-based Bligh and Dyer...
A key element of successful lipidomics analysis is a sufficient extraction of lipid molecules typically by two-phase systems such as chloroform-based Bligh and Dyer (B&D). However, numerous metabolomics and lipidomics studies today apply easy to use one-phase extractions. In this work, quantitative flow injection analysis high-resolution mass spectrometry was applied to benchmark the lipid recovery of popular one-phase extraction methods for human plasma samples. The following organic solvents were investigated: methanol (MeOH), ethanol (EtOH), 2-propanol (IPA), 1-butanol (BuOH), acetonitrile (ACN) and the solvent mixtures BuOH/MeOH (3:1) and MeOH/ACN (1:1). The recovery of polar lysophospholipids was sufficient for all tested solvents. However, nonpolar lipid classes such as triglycerides (TG) and cholesteryl esters (CE) revealed extraction efficiencies less than 5% due to precipitation in polar solvents EtOH, MeOH, MeOH/ACN, and ACN. Sample pellets also contained a substantial amount of phospholipids, for example, more than 75% of total phosphatidylcholine and sphingomyelin for ACN. The loss of lipids by precipitation was directly related to the polarity of solvents and lipid classes. Although, lipid recovery increased with the volume of organic solvent, recovery in polar MeOH remains incomplete also for less polar lipid classes such as ceramides. Addition of stable isotope-labeled internal standards prior to lipid extraction could compensate for insufficient lipid recovery for polar lipid classes including lysolipids and phospholipids but not for nonpolar CE and TG. In summary, application of one-phase extractions should be limited to polar lipid classes unless sufficient recovery/solubility of nonpolar lipids has been demonstrated. The presented data reveal that appropriate lipid extraction efficiency is fundamental to achieve accurate lipid quantification.
Topics: Benchmarking; Humans; Lipidomics; Mass Spectrometry; Methanol; Phospholipids; Solvents; Triglycerides
PubMed: 36048752
DOI: 10.1021/acs.analchem.2c02117 -
Environmental Microbiology May 2023The ammonia monooxygenase (AMO) is a key enzyme in ammonia-oxidizing archaea, which are abundant and ubiquitous in soil environments. The AMO belongs to the...
The ammonia monooxygenase (AMO) is a key enzyme in ammonia-oxidizing archaea, which are abundant and ubiquitous in soil environments. The AMO belongs to the copper-containing membrane monooxygenase (CuMMO) enzyme superfamily, which also contains particulate methane monooxygenase (pMMO). Enzymes in the CuMMO superfamily are promiscuous, which results in co-oxidation of alternative substrates. The phylogenetic and structural similarity between the pMMO and the archaeal AMO is well-established, but there is surprisingly little information on the influence of methane and methanol on the archaeal AMO and terrestrial nitrification. The aim of this study was to examine the effects of methane and methanol on the soil ammonia-oxidizing archaeon 'Candidatus Nitrosocosmicus franklandus C13'. We demonstrate that both methane and methanol are competitive inhibitors of the archaeal AMO. The inhibition constants (K ) for methane and methanol were 2.2 and 20 μM, respectively, concentrations which are environmentally relevant and orders of magnitude lower than those previously reported for ammonia-oxidizing bacteria. Furthermore, we demonstrate that a specific suite of proteins is upregulated and downregulated in 'Ca. Nitrosocosmicus franklandus C13' in the presence of methane or methanol, which provides a foundation for future studies into metabolism of one-carbon (C1) compounds in ammonia-oxidizing archaea.
Topics: Archaea; Methanol; Ammonia; Methane; Phylogeny; Oxidation-Reduction; Soil
PubMed: 36598494
DOI: 10.1111/1462-2920.16316 -
Natural Product Research Jul 2022Reinvestigation of a methanol extract of afforded a new 3- hydroxyisoflavanone, 3,5,7,2',4'-pentahydroxyisoflavanone (), two new monoaryl glucosides,...
Reinvestigation of a methanol extract of afforded a new 3- hydroxyisoflavanone, 3,5,7,2',4'-pentahydroxyisoflavanone (), two new monoaryl glucosides, 3,4-dimethoxyphenyl 1--(6'--acetyl)--D-glucopyranoside ( and 3,4,5-trimethoxyphenyl 1--(6'--acetyl)--D-glucopyranoside (), in addition to three known compounds, 3'--methylorobol (), robusflavone B (), and apigenin (). The structural elucidation of these compounds was achieved by analyses of their spectroscopic data (HR-ESI-MS, 1 D- and 2 D-NMR) and acidic hydrolysis. The extracts and compounds - exhibited weak or no cytotoxic activity against KB, HepG2, Lu and MCF7 cell lines.
Topics: Fabaceae; Glucosides; Methanol; Phenols; Plant Extracts
PubMed: 33350349
DOI: 10.1080/14786419.2020.1860973 -
Microbiology (Reading, England) Jul 2020Methylotrophic yeasts of the genus are abundantly found in tree exudates. Their ability to utilize methanol as carbon and energy source relies on an assimilation... (Review)
Review
Methylotrophic yeasts of the genus are abundantly found in tree exudates. Their ability to utilize methanol as carbon and energy source relies on an assimilation pathway localized in largely expanded peroxisomes, and a cytosolic methanol dissimilation pathway. Other substrates like glucose or glycerol are readily utilized as well. yeasts usually grow as haploid cells and are secondary homothallic as they can switch mating type. Upon mating diploid cells sporulate readily, forming asci with four haploid spores. Their ability to secrete high amounts of heterologous proteins made them interesting for biotechnology, which expands today also to other products of primary and secondary metabolism.
Topics: Biotechnology; Fungal Proteins; Methanol; Phylogeny; Recombinant Proteins; Saccharomycetales
PubMed: 32720891
DOI: 10.1099/mic.0.000958