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1.
J Agric Food Chem ; 72(25): 14152-14164, 2024 Jun 26.
Article in English | MEDLINE | ID: mdl-38869049

ABSTRACT

Golden apple snail (Pomacea canaliculata), a major alien invasive organism in China, affects food production and poses a threat to human health. Metaldehyde is a highly effective, commonly used snail killer with low toxicity. Virulence determination, tissue section, iTRAQ and RNA interference were used to systematically study the toxicity of metaldehyde on P. canaliculata. The molluscicidal activity tests showed that metaldehyde exhibits strong toxicity against P. canaliculata. Physiological and biochemical data indicate that metaldehyde can cause damage to the gills, liver, pancreas, and kidneys of snails, also reduce the oxygen consumption rate and ammonia excretion rate of golden apple snails, and cause neurological diseases. The proteome of the gill region of the golden apple snail after exposure to metaldehyde was analyzed by using iTRAQ technology. A total of 360 differential proteins were identified, and four target proteins were screened, namely, alpha-protein kinase 1 (ALPK1), cubilin (CUBN), sodium- and chloride-dependent GABA transporter 2 (GAT2), and acetylcholinesterase (AChE). RNAi was used to target the four proteins. After the ALPK1 and CUBN protein genes were interfered with by metaldehyde treatment, it was found that the mortality rate of the golden apple snail significantly increased. However, interference of GAT2 and AChE protein genes by metaldehyde led to no significant change in the mortality rates of the snails. The histopathological observation of the gill showed that the rate of cilia shedding in the gill decreased after the interference of ALPK1 and CUBN protein genes.


Subject(s)
Molluscacides , Snails , Animals , Snails/genetics , Snails/metabolism , Molluscacides/metabolism , Acetaldehyde/analogs & derivatives , Acetaldehyde/metabolism , Acetaldehyde/toxicity , Gills/metabolism , Gills/drug effects , Acetylcholinesterase/metabolism , Acetylcholinesterase/genetics , China
2.
Anal Methods ; 16(26): 4322-4332, 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38888243

ABSTRACT

Microdialysis is an important technique for in vivo sampling of tissue's biochemical composition. Understanding the factors that affect the performance of the microdialysis probes and developing methods for sample analysis are crucial for obtaining reliable results. In this work, we used experimental and numerical procedures to study the performance of microdialysis probes having different configurations, membrane materials and dimensions. For alcohol research, it is important to understand the dynamics of ethanol metabolism, particularly in the brain and in other organs, and to simultaneously measure the concentrations of ethanol and its metabolites - acetaldehyde and acetate. Our work provides a comprehensive characterization of three microdialysis probes, in terms of recovery rates and backpressure, allowing for interpretation and optimization of experimental procedures. In vivo experiments were performed to measure the time course concentration of ethanol, acetaldehyde, and acetate in the rat brain dialysate. Additionally, the combination of in vitro experimental results with numerical simulations enabled us to calculate diffusion coefficients of molecules in the microdialysis membranes and study the extent of the depletion effect caused by continuous microdialysis sampling, thus providing additional insights for probe selection and data interpretation.


Subject(s)
Brain , Ethanol , Microdialysis , Microdialysis/methods , Ethanol/metabolism , Ethanol/analysis , Ethanol/pharmacokinetics , Animals , Rats , Brain/metabolism , Acetaldehyde/analysis , Acetaldehyde/metabolism , Male , Acetates/metabolism , Acetates/pharmacokinetics
3.
Molecules ; 29(12)2024 Jun 19.
Article in English | MEDLINE | ID: mdl-38930972

ABSTRACT

Copper (II), a vital fungicide in organic viticulture, also acts as a wine oxidation catalyst. However, limited data are currently available on the impact that maximum allowed copper (II) ion doses in wine grapes at harvest can have on aged wine quality. This was the focus of the present study. We investigated the copper (II) effects by producing both white and red wines from musts containing three initial metal concentrations according to the limits set for organic farming. In detail, the influence of copper (II) on fermentation evolution, chromatic characteristics, and phenolic compounds was evaluated. Interestingly, the white wine obtained with the highest permitted copper (II) dose initially exceeded the concentration of 1.0 mg/L at fermentation completion. However, after one year of storage, the copper (II) content fell below 0.2 ± 0.01 mg/L. Conversely, red wines showed copper (II) levels below 1.0 mg/L at the end of fermentation, but the initial copper (II) level in musts significantly affected total native anthocyanins, color intensity, hue, and acetaldehyde concentration. After 12-month aging, significant differences were observed in polymeric pigments, thus suggesting a potential long-term effect of copper (II) on red wine color stability.


Subject(s)
Acetaldehyde , Copper , Fermentation , Phenols , Vitis , Wine , Wine/analysis , Copper/analysis , Acetaldehyde/analysis , Phenols/analysis , Phenols/chemistry , Vitis/chemistry , Color , Anthocyanins/analysis , Anthocyanins/chemistry
4.
Environ Geochem Health ; 46(7): 248, 2024 Jun 14.
Article in English | MEDLINE | ID: mdl-38874631

ABSTRACT

All pests can be eliminated with the help of pesticides, which can be either natural or synthetic. Because of the excessive use of pesticides, it is harmful to both ecology and people's health. Pesticides are categorised according to several criteria: their chemical composition, method of action, effects, timing of use, source of manufacture, and formulations. Many aquatic animals, birds, and critters live in danger owing to hazardous pesticides. Metaldehyde is available in various forms and causes significant impact even when small amounts are ingested. Metaldehyde can harm wildlife, including dogs, cats, and birds. This review discusses pesticides, their types and potential environmental issues, and metaldehyde's long-term effects. In addition, it examines ways to eliminate metaldehyde from the aquatic ecosystem before concluding by anticipating how pesticides may affect society. The metal-organic framework and other biosorbents have been appropriately synthesized and subsequently represent the amazing removal of pesticides from effluent as an enhanced adsorbent, such as magnetic nano adsorbents. A revision of the risk assessment for metaldehyde residuals in aqueous sources is also attempted.


Subject(s)
Acetaldehyde , Pesticides , Water Pollutants, Chemical , Acetaldehyde/analogs & derivatives , Animals , Risk Assessment , Humans , Adsorption , Metal-Organic Frameworks/chemistry
5.
J Am Soc Mass Spectrom ; 35(6): 1261-1271, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38780179

ABSTRACT

We investigated the applicability of proton transfer reaction-time-of-flight mass spectrometry (PTR-TOF-MS) for quantitative analysis of mixtures comprising glycerin, acetol, glycidol, acetaldehyde, acetone, and propylene glycol. While PTR-TOF-MS offers real-time simultaneous determination, the method selectivity is limited when analyzing compounds with identical elemental compositions or when labile compounds present in the mixture produce fragments that generate overlapping ions with other matrix components. In this study, we observed significant fragmentation of glycerin, acetol, glycidol, and propylene glycol during protonation via hydronium ions (H3O+). Nevertheless, specific ions generated by glycerin (m/z 93.055) and propylene glycol (m/z 77.060) enabled their selective detection. To thoroughly investigate the selectivity of the method, various mixtures containing both isotope-labeled and unlabeled compounds were utilized. The experimental findings demonstrated that when samples contained high levels of glycerin, it was not feasible to perform time-resolved analysis in H3O+ mode for acetaldehyde, acetol, and glycidol. To overcome the observed selectivity limitations associated with the H3O+ reagent ions, alternative ionization modes were investigated. The ammonium ion mode proved appropriate for analyzing propylene glycol (m/z 94.086) and acetone (m/z 76.076) mixtures. Concerning the nitric oxide mode, specific m/z were identified for acetaldehyde (m/z 43.018), acetone (m/z 88.039), glycidol (m/z 73.028), and propylene glycol (m/z 75.044). It was concluded that considering the presence of multiple product ions and the potential influence of other compounds, it is crucial to conduct a thorough selectivity assessment when employing PTR-TOF-MS as the sole method for analyzing compounds in complex matrices of unknown composition.


Subject(s)
Electronic Nicotine Delivery Systems , Mass Spectrometry , Nicotiana , Volatile Organic Compounds , Mass Spectrometry/methods , Volatile Organic Compounds/analysis , Volatile Organic Compounds/chemistry , Nicotiana/chemistry , Propylene Glycol/analysis , Propylene Glycol/chemistry , Acetaldehyde/analysis , Acetaldehyde/chemistry , Acetone/analysis , Acetone/chemistry , Acetone/analogs & derivatives , Glycerol/analysis , Glycerol/chemistry , Hot Temperature , Epoxy Compounds/chemistry , Epoxy Compounds/analysis , Propanols/chemistry , Propanols/analysis
6.
Spectrochim Acta A Mol Biomol Spectrosc ; 318: 124515, 2024 Oct 05.
Article in English | MEDLINE | ID: mdl-38810435

ABSTRACT

Mirabegron (MRB) is a ß3-adrenoceptor agonist used for managing overactive bladder syndrome. A cost-effective, environmentally friendly, and highly sensitive spectrofluorimetric method was suggested to serve the purpose of quantifying MRB in its pure state, pharmaceutical tablets, spiked human plasma and urine, and testing content uniformity. In the present study, ninhydrin and phenylacetaldehyde react with the amino group moiety of MRB in Teorell-Stenhagen buffer (pH 7.5) to generate a strongly fluorescent diaryl pyrrolone compound that emits fluorescence at a wavelength of 477 nm upon excitation at 385 nm. The obtained calibration curve showed a linear relationship with a high correlation coefficient (r = 0.9997) in the concentration range of 0.25 to 5.0 µg mL-1. Limits of detection (LOD) and quantitation (LOQ) were 0.082 and 0.248 µg mL-1 respectively. The procedure was verified in accordance with the ICH guidelines. The suggested approach could be utilized for the selective analysis of MRB in its pharmaceuticals, either containing a single drug or co-formulated with solifenacin succinate. The greenness of the suggested method was confirmed using different green analytical metrics.


Subject(s)
Acetanilides , Limit of Detection , Ninhydrin , Spectrometry, Fluorescence , Thiazoles , Humans , Ninhydrin/chemistry , Spectrometry, Fluorescence/methods , Acetanilides/urine , Acetanilides/blood , Acetanilides/chemistry , Thiazoles/chemistry , Thiazoles/urine , Thiazoles/blood , Pyrroles/chemistry , Fluorescent Dyes/chemistry , Fluorescent Dyes/chemical synthesis , Tablets , Acetaldehyde/analogs & derivatives
8.
Astrobiology ; 24(5): 489-497, 2024 May.
Article in English | MEDLINE | ID: mdl-38696654

ABSTRACT

Ribose is the defining sugar in ribonucleic acid (RNA), which is often proposed to have carried the genetic information and catalyzed the biological reactions of the first life on Earth. Thus, abiological processes that yield ribose under prebiotic conditions have been studied for decades. However, aqueous environments required for the formation of ribose from materials available in quantity under geologically reasonable models, where the ribose formed is not immediately destroyed, remain unclear. This is due in large part to the challenge of analysis of carbohydrates formed under a wide range of aqueous conditions. Thus, the formation of ribose on prebiotic Earth has sometimes been questioned. We investigated the quantitative effects of pH, temperature, cation, and the concentrations of formaldehyde and glycolaldehyde on the synthesis of diverse sugars, including ribose. The results suggest a range of conditions that produce ribose and that ribose could have formed in constrained aquifers on prebiotic Earth.


Subject(s)
Formaldehyde , Ribose , Temperature , Water , Ribose/chemistry , Hydrogen-Ion Concentration , Water/chemistry , Formaldehyde/chemistry , Acetaldehyde/chemistry , Acetaldehyde/analogs & derivatives , Earth, Planet , Origin of Life
9.
Plant J ; 119(1): 84-99, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38578218

ABSTRACT

Tuta absoluta ("leafminer"), is a major pest of tomato crops worldwide. Controlling this insect is difficult due to its efficient infestation, rapid proliferation, and resilience to changing weather conditions. Furthermore, chemical pesticides have only a short-term effect due to rapid development of T. absoluta strains. Here, we show that a variety of tomato cultivars, treated with external phenylalanine solutions exhibit high resistance to T. absoluta, under both greenhouse and open field conditions, at different locations. A large-scale metabolomic study revealed that tomato leaves absorb and metabolize externally given Phe efficiently, resulting in a change in their volatile profile, and repellence of T. absoluta moths. The change in the volatile profile is due to an increase in three phenylalanine-derived benzenoid phenylpropanoid volatiles (BPVs), benzaldehyde, phenylacetaldehyde, and 2-phenylethanol. This treatment had no effect on terpenes and green leaf volatiles, known to contribute to the fight against insects. Phe-treated plants also increased the resistance of neighboring non-treated plants. RNAseq analysis of the neighboring non-treated plants revealed an exclusive upregulation of genes, with enrichment of genes related to the plant immune response system. Exposure of tomato plants to either benzaldehyde, phenylacetaldehyde, or 2-phenylethanol, resulted in induction of genes related to the plant immune system that were also induced due to neighboring Phe-treated plants. We suggest a novel role of phenylalanine-derived BPVs as mediators of plant-insect interactions, acting as inducers of the plant defense mechanisms.


Subject(s)
Phenylalanine , Plant Leaves , Solanum lycopersicum , Volatile Organic Compounds , Solanum lycopersicum/genetics , Solanum lycopersicum/metabolism , Solanum lycopersicum/parasitology , Phenylalanine/metabolism , Volatile Organic Compounds/metabolism , Animals , Plant Leaves/metabolism , Plant Leaves/drug effects , Plant Leaves/parasitology , Benzaldehydes/metabolism , Benzaldehydes/pharmacology , Acetaldehyde/analogs & derivatives , Acetaldehyde/metabolism , Acetaldehyde/pharmacology , Moths/physiology , Moths/drug effects , Plant Diseases/parasitology , Plant Diseases/immunology , Manduca/physiology
10.
Cell Cycle ; 23(4): 369-384, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38571319

ABSTRACT

Acetaldehyde, a chemical that can cause DNA damage and contribute to cancer, is prevalently present in our environment, e.g. in alcohol, tobacco, and food. Although aldehyde potentially promotes crosslinking reactions among biological substances including DNA, RNA, and protein, it remains unclear what types of DNA damage are caused by acetaldehyde and how they are repaired. In this study, we explored mechanisms involved in the repair of acetaldehyde-induced DNA damage by examining the cellular sensitivity to acetaldehyde in the collection of human TK6 mutant deficient in each genome maintenance system. Among the mutants, mismatch repair mutants did not show hypersensitivity to acetaldehyde, while mutants deficient in base and nucleotide excision repair pathways or homologous recombination (HR) exhibited higher sensitivity to acetaldehyde than did wild-type cells. We found that acetaldehyde-induced RAD51 foci representing HR intermediates were prolonged in HR-deficient cells. These results indicate a pivotal role of HR in the repair of acetaldehyde-induced DNA damage. These results suggest that acetaldehyde causes complex DNA damages that require various types of repair pathways. Mutants deficient in the removal of protein adducts from DNA ends such as TDP1-/- and TDP2-/- cells exhibited hypersensitivity to acetaldehyde. Strikingly, the double mutant deficient in both TDP1 and RAD54 showed similar sensitivity to each single mutant. This epistatic relationship between TDP1-/- and RAD54-/- suggests that the protein-DNA adducts generated by acetaldehyde need to be removed for efficient repair by HR. Our study would help understand the molecular mechanism of the genotoxic and mutagenic effects of acetaldehyde.


Subject(s)
Acetaldehyde , DNA Damage , DNA Repair , Homologous Recombination , Acetaldehyde/toxicity , Humans , Homologous Recombination/drug effects , Homologous Recombination/genetics , DNA Repair/drug effects , Rad51 Recombinase/metabolism , Rad51 Recombinase/genetics , Mutation/genetics , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/genetics , Cell Line
11.
Environ Pollut ; 350: 123971, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38641033

ABSTRACT

Haloacetaldehyde disinfection by-products (HAL-DBPs) are among the top three unregulated DBPs found in drinking water. The cytotoxicity and genotoxicity of HALs are much higher than that of the regulated trihalomethanes and haloacetic acids. Previous studies have mainly focused on the toxic effects of single HAL, with few examining the toxic effects of mixed exposures to HALs. The study aimed to observe the effects of mixed exposures of 1∼1000X the realistic level of HALs on the hepatotoxicity and lipid metabolism of C57BL/6J mice, based on the component and concentration of HALs detected in the finished water of Shanghai. Exposure to realistic levels of HALs led to a significant increase in phosphorated acetyl CoA carboxylase 1 (p-ACC1) in the hepatic de novo lipogenesis (DNL) pathway. Additionally, exposure to 100X realistic levels of HALs resulted in significant alterations to key enzymes of DNL pathway, including ACC1, fatty acid synthase (FAS), and diacylglycerol acyltransferase 2 (DGAT2), as well as key proteins of lipid disposal such as carnitine palmitoyltransferase 1 (CPT-1) and peroxisome proliferator activated receptor α (PPARα). Exposure to 1000X realistic levels of HALs significantly increased hepatic and serum triglyceride levels, as well as total cholesterol, low-density lipoprotein, alanine aminotransferase, aspartate transaminase, alkaline phosphatase, and lactate dehydrogenase levels, significantly decreased high-density lipoprotein. Meanwhile, histopathological analysis demonstrated that HALs exacerbated tissue vacuolization and inflammatory cell infiltration in mice livers, which showed the typical phenotypes of non-alcoholic fatty liver disease (NAFLD). These results suggested that the HALs mixture is a critical risk factor for NAFLD and is significantly highly toxic to C57BL/6J mice.


Subject(s)
Acetaldehyde , Lipid Metabolism , Liver , Mice, Inbred C57BL , Animals , Mice , Liver/drug effects , Liver/metabolism , Acetaldehyde/toxicity , Acetaldehyde/analogs & derivatives , Lipid Metabolism/drug effects , Male , Disinfection , Water Pollutants, Chemical/toxicity , Acetyl-CoA Carboxylase/metabolism , PPAR alpha/metabolism , Diacylglycerol O-Acyltransferase/metabolism , Diacylglycerol O-Acyltransferase/genetics , Carnitine O-Palmitoyltransferase/metabolism , Carnitine O-Palmitoyltransferase/genetics , Lipogenesis/drug effects , Disinfectants/toxicity , Fatty Acid Synthases/metabolism , China , Drinking Water/chemistry
12.
Medicine (Baltimore) ; 103(16): e37820, 2024 Apr 19.
Article in English | MEDLINE | ID: mdl-38640328

ABSTRACT

Aldehyde dehydrogenase 2 (ALDH2) plays a critical role in safeguarding cells against acetaldehyde toxicity and is closely linked to human metabolism. Nevertheless, the involvement of ALDH2 in cancer remains enigmatic. This investigation seeks to comprehensively assess ALDH2's significance in pan-cancer. We conducted an all-encompassing analysis of pan-cancer utilizing multiple databases, including TCGA, linkedomicshs, UALCAN, and Kaplan-Meier plotter. We employed diverse algorithms such as EPIC, MCPCOUNTER, TIDTIMER, xCell, MCP-counter, CIBERSORT, quanTIseq, and EPIC to examine the connection between ALDH2 expression and immune cell infiltration. Single-cell sequencing analysis furnished insights into ALDH2's functional status in pan-cancer. Immunohistochemical staining was performed to validate ALDH2 expression in cancer tissues. In a comprehensive assessment, we observed that tumor tissues demonstrated diminished ALDH2 expression levels compared to normal tissues across 16 different cancer types. ALDH2 expression exhibited a significant positive correlation with the infiltration of immune cells, including CD4 + T cells, CD8 + T cells, neutrophils, B cells, and macrophages, in various tumor types. Moreover, this study explored the association between ALDH2 and patient survival, examined the methylation patterns of ALDH2 in normal and primary tumor tissues, and delved into genetic variations and mutations of ALDH2 in tumors. The findings suggest that ALDH2 could serve as a valuable prognostic biomarker in pan-cancer, closely linked to the tumor's immune microenvironment.


Subject(s)
Acetaldehyde , Aldehyde Dehydrogenase, Mitochondrial , Neoplasms , Humans , Aldehyde Dehydrogenase, Mitochondrial/genetics , Aldehyde Dehydrogenase, Mitochondrial/immunology , Aldehyde Dehydrogenase, Mitochondrial/metabolism , Algorithms , Biomarkers , Neoplasms/genetics , Prognosis , Tumor Microenvironment/immunology
13.
Sci Total Environ ; 929: 172629, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38649057

ABSTRACT

In the context of the increasing global use of ethanol biofuel, this work investigates the concentrations of ethanol, methanol, and acetaldehyde, in both the gaseous phase and rainwater, across six diverse urban regions and biomes in Brazil, a country where ethanol accounts for nearly half the light-duty vehicular fuel consumption. Atmospheric ethanol median concentrations in São Paulo (SP) (12.3 ± 12.1 ppbv) and Ribeirão Preto (RP) (12.1 ± 10.9 ppbv) were remarkably close, despite the SP vehicular fleet being ∼13 times larger. Likewise, the rainwater VWM ethanol concentration in SP (4.64 ± 0.38 µmol L-1) was only 26 % higher than in RP (3.42 ± 0.13 µmol L-1). This work demonstrated the importance of evaporative emissions, together with biomass burning, as sources of the compounds studied. The importance of biogenic emissions of methanol during forest flooding was identified in campaigns in the Amazon and Atlantic forests. Marine air masses arriving at a coastal site led to the lowest concentrations of ethanol measured in this work. Besides vehicular and biomass burning emissions, secondary formation of acetaldehyde by photochemical reactions may be relevant in urban and non-urban regions. The combined deposition flux of ethanol and methanol was 6.2 kg ha-1 year-1, avoiding oxidation to the corresponding and more toxic aldehydes. Considering the species determined here, the ozone formation potential (OFP) in RP was around two-fold higher than in SP, further evidencing the importance of emissions from regional distilleries and biomass burning, in addition to vehicles. At the forest and coastal sites, the OFP was approximately 5 times lower than at the urban sites. Our work evidenced that transition from gasoline to ethanol or ethanol blends brings the associated risk of increasing the concentrations of highly toxic aldehydes and ozone, potentially impacting the atmosphere and threatening air quality and human health in urban areas.


Subject(s)
Acetaldehyde , Air Pollutants , Environmental Monitoring , Ethanol , Methanol , Rain , Brazil , Acetaldehyde/analysis , Ethanol/analysis , Methanol/analysis , Air Pollutants/analysis , Cities
14.
Food Chem ; 449: 138944, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-38613993

ABSTRACT

Sulfite addition is a common tool for ensuring wines' oxidative stability via the activity of its free and weakly bound molecular fraction. As a nucleophile, bisulfite forms covalent adducts with wine's most relevant electrophiles, such as carbonyls, polyphenols, and thiols. The equilibrium in these reactions is often represented as dissociation rather than formation. Recent studies from our laboratory demonstrate, first, the acetaldehyde sulfonate dissociation, and second, the chemical stability of cysteine and epicatechin sulfonates under wine aging conditions. Thus, the objective of this study was to monitor by 1H NMR the binding specificity of known carbonyl-derived SO2 binders (acetaldehyde and pyruvic acid) in the presence of S-containing compounds (cysteine and glutathione). We report that during simulated wine aging, the sulfur dioxide that is rapidly bound to carbonyl compounds will be released and will bind to cysteine and glutathione, demonstrating the long-term sulfur dioxide binding potential of S-containing compounds. These results are meant to serve as a complement to existing literature reviews focused on molecular markers related to wines' oxidative stability and emphasize once more the importance of S-containing compounds in wine aging chemical mechanisms.


Subject(s)
Sulfhydryl Compounds , Wine , Wine/analysis , Kinetics , Sulfhydryl Compounds/chemistry , Oxidation-Reduction , Sulfur Dioxide/chemistry , Cysteine/chemistry , Cysteine/metabolism , Acetaldehyde/chemistry , Sulfites/chemistry , Proton Magnetic Resonance Spectroscopy , Magnetic Resonance Spectroscopy , Glutathione/chemistry , Glutathione/metabolism
15.
Chemosphere ; 358: 142118, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38677616

ABSTRACT

A comprehensive kinetic model has been developed to address the factors and processes governing the photocatalytic removal of gaseous ethanol by using ZnO loaded in a prototype air purifier. This model simultaneously tracks the concentrations of ethanol and acetaldehyde (as its primary oxidation product) in both gas phase and on the catalyst surface. It accounts for reversible adsorption of both compounds to assign kinetic reaction parameters for different degradation pathways. The effects of oxygen vacancies on the catalyst have been validated through the comparative assessment on the catalytic performance of commercial ZnO before and after the reduction pre-treatment (10% H2/Ar gas at 500 °C). The influence of humidity has also been assessed by partitioning the concentrations of water molecules across the gas phase and catalyst surface interface. Given the significant impact of adsorption on photocatalytic processes, the beginning phases of all experiments (15 min in the dark) are integrated into the model. Results showcase a notable decrease in the adsorption removal of ethanol and acetaldehyde with an increase in relative humidity from 5% to 75%. The estimated number of active sites, as determined by the model, increases from 7.34 10-6 in commercial ZnO to 8.86 10-6 mol gcat-1 in reduced ZnO. Furthermore, the model predicts that the reaction occurs predominantly on the catalyst surface while only 14% in the gas phase. By using quantum yield calculations, the optimal humidity level for photocatalytic degradation is identified as 25% with the highest quantum yield of 6.98 10-3 (commercial ZnO) and 10.41 10-3 molecules photon-1 (reduced ZnO) catalysts.


Subject(s)
Acetaldehyde , Ethanol , Humidity , Oxygen , Zinc Oxide , Zinc Oxide/chemistry , Acetaldehyde/chemistry , Kinetics , Ethanol/chemistry , Catalysis , Oxygen/chemistry , Adsorption , Air Pollutants/chemistry , Oxidation-Reduction , Models, Chemical
16.
Chem Biol Interact ; 394: 110992, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38579923

ABSTRACT

Histidine residues 44 and 48 in yeast alcohol dehydrogenase (ADH) bind to the coenzymes NAD(H) and contribute to catalysis. The individual H44R and H48Q substitutions alter the kinetics and pH dependencies, and now the roles of other ionizable groups in the enzyme were studied in the doubly substituted H44R/H48Q ADH. The substitutions make the enzyme more resistant to inactivation by diethyl pyrocarbonate, modestly improve affinity for coenzymes, and substantially decrease catalytic efficiencies for ethanol oxidation and acetaldehyde reduction. The pH dependencies for several kinetic parameters are shifted from pK values for wild-type ADH of 7.3-8.1 to values for H44R/H48Q ADH of 8.0-9.6, and are assigned to the water or alcohol bound to the catalytic zinc. It appears that the rate of binding of NAD+ is electrostatically favored with zinc-hydroxide whereas binding of NADH is faster with neutral zinc-water. The pH dependencies of catalytic efficiencies (V/EtKm) for ethanol oxidation and acetaldehyde reduction are similarly controlled by deprotonation and protonation, respectively. The substitutions make an enzyme that resembles the homologous horse liver H51Q ADH, which has Arg-47 and Gln-51 and exhibits similar pK values. In the wild-type ADHs, it appears that His-48 (or His-51) in the proton relay systems linked to the catalytic zinc ligands modulate catalytic efficiencies.


Subject(s)
Alcohol Dehydrogenase , Catalytic Domain , Histidine , Saccharomyces cerevisiae , Acetaldehyde/metabolism , Acetaldehyde/chemistry , Alcohol Dehydrogenase/metabolism , Alcohol Dehydrogenase/genetics , Alcohol Dehydrogenase/chemistry , Amino Acid Substitution , Diethyl Pyrocarbonate/chemistry , Diethyl Pyrocarbonate/pharmacology , Ethanol/metabolism , Histidine/metabolism , Histidine/chemistry , Hydrogen-Ion Concentration , Kinetics , NAD/metabolism , Oxidation-Reduction , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae/enzymology , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae Proteins/chemistry , Saccharomyces cerevisiae Proteins/genetics , Zinc/metabolism , Zinc/chemistry
17.
Methods Enzymol ; 696: 179-199, 2024.
Article in English | MEDLINE | ID: mdl-38658079

ABSTRACT

ß-Hydroxy-α-amino acids (ßHAAs) are an essential class of building blocks of therapeutically important compounds and complex natural products. They contain two chiral centers at Cα and Cß positions, resulting in four possible diastereoisomers. Many innovative asymmetric syntheses have been developed to access structurally diverse ßHAAs. The main challenge, however, is the control of the relative and absolute stereochemistry of the asymmetric carbons in a sustainable way. In this respect, there has been considerable attention focused on the chemoenzymatic synthesis of ßHAAs via a one-step process. Nature has evolved different enzymatic routes to produce these valuable ßHAAs. Among these naturally occurring transformations, L-threonine transaldolases present potential biocatalysts to generate ßHAAs in situ. 4-Fluorothreonine transaldolase from Streptomyces sp. MA37 (FTaseMA) catalyzes the cross-over transaldolation reaction between L-Thr and fluoroacetaldehyde to give 4-fluorothreonine and acetaldehyde (Ad). It has been demonstrated that FTaseMA displays considerable substrate plasticity toward structurally diverse aldehyde acceptors, leading to the production of various ßHAAs. In this chapter, we describe methods for the preparation of FTaseMA, and the chemoenzymatic synthesis of ßHAAs from various aldehydes and L-Thr using FTaseMA.


Subject(s)
Streptomyces , Transaldolase , Streptomyces/enzymology , Transaldolase/metabolism , Transaldolase/chemistry , Transaldolase/genetics , Threonine/analogs & derivatives , Threonine/chemistry , Threonine/metabolism , Biocatalysis , Amino Acids/chemistry , Amino Acids/metabolism , Substrate Specificity , Acetaldehyde/analogs & derivatives , Acetaldehyde/metabolism , Acetaldehyde/chemistry , Bacterial Proteins/metabolism , Bacterial Proteins/chemistry , Enzyme Assays/methods , Stereoisomerism
18.
ACS Infect Dis ; 10(4): 1312-1326, 2024 04 12.
Article in English | MEDLINE | ID: mdl-38513073

ABSTRACT

New antimicrobial strategies are needed to address pathogen resistance to currently used antibiotics. Bacterial central metabolism is a promising target space for the development of agents that selectively target bacterial pathogens. 1-Deoxy-d-xylulose 5-phosphate synthase (DXPS) converts pyruvate and d-glyceraldehyde 3-phosphate (d-GAP) to DXP, which is required for synthesis of essential vitamins and isoprenoids in bacterial pathogens. Thus, DXPS is a promising antimicrobial target. Toward this goal, our lab has demonstrated selective inhibition of Escherichia coli DXPS by alkyl acetylphosphonate (alkylAP)-based bisubstrate analogs that exploit the requirement for ternary complex formation in the DXPS mechanism. Here, we present the first DXPS structure with a bisubstrate analog bound in the active site. Insights gained from this cocrystal structure guided structure-activity relationship studies of the bisubstrate scaffold. A low nanomolar inhibitor (compound 8) bearing a gem-dibenzyl glycine moiety conjugated to the acetylphosphonate pyruvate mimic via a triazole-based linker emerged from this study. Compound 8 was found to exhibit slow, tight-binding inhibition, with contacts to E. coli DXPS residues R99 and R478 demonstrated to be important for this behavior. This work has discovered the most potent DXPS inhibitor to date and highlights a new role of R99 that can be exploited in future inhibitor designs toward the development of a novel class of antimicrobial agents.


Subject(s)
Acetaldehyde/analogs & derivatives , Bacteria , Escherichia coli , Transferases , Anti-Bacterial Agents/chemistry , Pyruvates/metabolism
19.
Food Chem ; 447: 139029, 2024 Jul 30.
Article in English | MEDLINE | ID: mdl-38513480

ABSTRACT

Hydrocolloids synthesized by gallic acid (GA) and ferulic acid (FA) grafting onto chitosan (CS) were characterized, and their effects on PhIP formation in pan-fried golden pompano were investigated. Spectrograms including nuclear magnetic resonance, Fourier transform infrared spectroscopy and ultraviolet-visible confirmed that GA and FA were successfully grafted onto CS via covalent bonds, with grafting degree of 97.06 ± 2.56 mg GA/g and 93.56 ± 2.76 mg FA/g, respectively. The CS-g-GA and CS-g-FA exerted better solubility and antioxidant activities than CS. For the 8-min pan-fried golden pompano fillets, CS-g-GA and CS-g-FA (0.5 %, m/v) significantly reduced the PhIP formation by 61.71 % and 81.64 %, respectively. Chemical models revealed that CS-g-GA and CS-g-FA inhibited PhIP formation mainly by decreasing the phenylacetaldehyde contents from Maillard reaction and competing with creatinine to react with phenylacetaldehyde. Therefore, it was suggested that CS-g-phenolic acids emerge as novel coating for aquatic products during processing and inhibit heterocyclic amines generation.


Subject(s)
Acetaldehyde/analogs & derivatives , Chitosan , Imidazoles , Chitosan/chemistry , Polyphenols , Antioxidants/chemistry , Gallic Acid/chemistry
20.
Pest Manag Sci ; 80(7): 3650-3664, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38456499

ABSTRACT

BACKGROUND: Metaldehyde is a molluscicide commonly used to control Pomacea canaliculate. Its efficacy is significantly impacted by water temperature, although the underlying mechanisms have not been fully explored. RESULTS: In this study, we systematically investigated the temperature effect and molecular mechanisms of metaldehyde on P. canaliculata. The molluscicidal effect at various temperatures indicated that metaldehyde's molluscicidal activity significantly decreases with a drop in temperature. The LC50 value was only 458.8176 mg/L at 10 °C, while it surged to a high of 0.8249 mg/L at 25 °C. The impact of low temperature (10 °C) on metaldehyde's molluscicidal activity was analyzed via transcriptomics. The results revealed that the effect of low temperature primarily influences immunity, lipid synthesis, and oxidative stress. The expression of stress and immune-related genes, such as MANF, HSP70, Cldf7, HSP60, and PclaieFc, significantly increased. Furthermore, we studied the function of five target genes using RNA interference (RNAi) and discovered that Cldf7 and HSP70 could notably affect metaldehyde's molluscicidal effect. The mortality of P. canaliculata increased by 36.17% (72 h) after Cldf7 interference and by 48.90% (72 h) after HSP70 interference. CONCLUSION: Our findings demonstrate that low temperature can induce the extensive expression of the Cldf7 and HSP70 genes, resulting in a substantial reduction in metaldehyde's molluscicidal activity. © 2024 Society of Chemical Industry.


Subject(s)
Cold Temperature , Molluscacides , Animals , Molluscacides/pharmacology , Gastropoda/drug effects , Gastropoda/genetics , Acetaldehyde/analogs & derivatives , Acetaldehyde/pharmacology
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