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1.
Food Res Int ; 186: 114397, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38729739

ABSTRACT

The formation mechanism behind the sophisticated aromas of sesame oil (SO) has not been elucidated. The interaction effects of the Maillard reaction (MR) and lipid oxidation on the aroma formation of fragrant sesame oil were investigated in model reaction systems made of l-lysine (Lys) and d-glucose (Glc) with or without fresh SO (FSO) or oxidized SO (OSO). The addition of OSO to the Lys-Glc model increased the MR browning at 294 nm and 420 nm and enhanced the DPPH radical scavenging activity greater than the addition of FSO (p < 0.05). The presence of lysine and glucose inhibited the oxidation of sesame oil, reduced the loss of γ-tocopherol, and facilitated the formation of sesamol (p < 0.05). The Maillard-lipid interaction led to the increased concentrations of some of the alkylpyrazines, alkylfurans, and MR-derived ketones and acids (p < 0.05) while reducing the concentrations of other pyrazines, lipid-derived furans, aliphatic aldehydes, ketones, alcohols, and acids (p < 0.05). The addition of FSO to the MR model enhanced the characteristic roasted, nutty, sweet, and fatty aromas in sesame oil (p < 0.05), while excessive lipid oxidation (OSO) brought about an unpleasant oxidized odor and reduced the characteristic aromas. This study helps to understand the sophisticated aroma formation mechanism in sesame oil and provides scientific instruction for precise flavor control in the production of sesame oil.


Subject(s)
Glucose , Lysine , Maillard Reaction , Odorants , Oxidation-Reduction , Sesame Oil , Sesame Oil/chemistry , Glucose/chemistry , Odorants/analysis , Lysine/chemistry , Phenols/chemistry , Benzodioxoles
2.
Food Res Int ; 183: 114183, 2024 May.
Article in English | MEDLINE | ID: mdl-38760123

ABSTRACT

A large number of volatile compounds are formed during the baking of foods by reactions such as caramelization and Maillard reactions. Elucidating the reaction mechanisms may be useful to predict and control food quality. Ten reaction volatile markers were extracted during baking of solid model cakes implemented with known amounts of precursors (glucose with or without leucine) and then quantified by Thermal desorption-Gas chromatography-Mass spectrometry. The kinetic data showed that the level of air convection in the oven had no significant influence on the reaction rates. In contrast, increasing baking temperatures had a nonlinear accelerating impact on the generation of newly formed volatile compounds with a bell-shaped kinetic curve found for most of the markers at 200 °C. The presence of leucine triggered the activation of the Maillard and Strecker routes with a specific and very rapid formation of 3-Methylbutanal and pyrazines. A dynamic model was developed, combining evaporation flow rate and kinetic formation and consumption of reaction markers. It can be used to describe, for two furanic compounds of different volatilities, the vapor concentrations in the oven from the concentrations measured in the model cakes.


Subject(s)
Cooking , Gas Chromatography-Mass Spectrometry , Glucose , Hot Temperature , Leucine , Maillard Reaction , Volatile Organic Compounds , Kinetics , Volatile Organic Compounds/analysis , Volatile Organic Compounds/chemistry , Cooking/methods , Glucose/chemistry , Glucose/analysis , Leucine/chemistry , Aldehydes/analysis , Aldehydes/chemistry , Pyrazines/analysis , Pyrazines/chemistry
3.
Molecules ; 29(9)2024 May 03.
Article in English | MEDLINE | ID: mdl-38731606

ABSTRACT

The polyphenol-Maillard reaction is considered one of the important pathways in the formation of humic-like substances (HLSs). Glucose serves as a microbial energy source that drives the humification process. However, the effects of changes in glucose, particularly its concentration, on abiotic pathways remain unclear. Given that the polyphenol-Maillard reaction requires high precursor concentrations and elevated temperatures (which are not present in soil), gibbsite was used as a catalyst to overcome energetic barriers. Catechol and glycine were introduced in fixed concentrations into a phosphate-buffered solution containing gibbsite using the liquid shake-flask incubation method, while the concentration of glucose was controlled in a sterile incubation system. The supernatant fluid and HLS components were dynamically extracted over a period of 360 h for analysis, thus revealing the influence of different glucose concentrations on abiotic humification pathways. The results showed the following: (1) The addition of glucose led to a higher degree of aromatic condensation in the supernatant fluid. In contrast, the supernatant fluid without glucose (Glu0) and the control group without any Maillard precursor (CK control group) exhibited lower degrees of aromatic condensation. Although the total organic C (TOC) content in the supernatant fluid decreased in all treatments during the incubation period, the addition of Maillard precursors effectively mitigated the decreasing trend of TOC content. (2) While the C content of humic-like acid (CHLA) and the CHLA/CFLA ratio (the ratio of humic-like acid to fulvic-like acid) showed varying increases after incubation, the addition of Maillard precursors resulted in a more noticeable increase in CHLA content and the CHLA/CFLA ratio compared to the CK control group. This indicated that more FLA was converted into HLA, which exhibited a higher degree of condensation and humification, thus improving the quality of HLS. The addition of glycine and catechol without glucose or with a glucose concentration of 0.06 mol/L was particularly beneficial in enhancing the degree of HLA humification. Furthermore, the presence of glycine and catechol, as well as higher concentrations of glucose, promoted the production of N-containing compounds in HLA. (3) The presence of Maillard precursors enhanced the stretching vibration of the hydroxyl group (-OH) of HLA. After the polyphenol-Maillard reaction of glycine and catechol with glucose concentrations of 0, 0.03, 0.06, 0.12, or 0.24 mol/L, the aromatic C structure in HLA products increased, while the carboxyl group decreased. The presence of Maillard precursors facilitated the accumulation of polysaccharides in HLA with higher glucose concentrations, ultimately promoting the formation of Al-O bonds. However, the quantities of phenolic groups and phenols in HLA decreased to varying extents.


Subject(s)
Glucose , Humic Substances , Maillard Reaction , Polyphenols , Humic Substances/analysis , Glucose/chemistry , Glucose/metabolism , Polyphenols/chemistry , Catechols/chemistry
4.
Biosens Bioelectron ; 258: 116336, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-38692222

ABSTRACT

As pure antipodes may differ in biological interactions, pharmacology, and toxicity, discrimination of enantiomers is important in the pharmaceutical and agrochemical industries. Two major challenges in enantiomer determination are transducing and amplifying the distinct chiral-recognition signals. In this study, a light-sensitive organic photoelectrochemical transistor (OPECT) with homochiral character is developed for enantiomer discrimination. Demonstrated with the discrimination of glucose enantiomers, the photoelectrochemically active gate electrode is prepared by integrating Au nanoparticles (AuNPs) and a chiral Cu(II)-metal-organic framework (c-CuMOF) onto TiO2 nanotube arrays (TNT). The captured glucose enantiomers are oxidized to hydrogen peroxide (H2O2) by the oxidase-mimicking AuNPs-loaded c-CuMOF. Based on the confinement effect of the mesopocket structure of the c-CuMOF and the remarkable charge transfer ability of the 1D nanotubular architecture, variations in H2O2 yield are translated into significant changes in OPECT drain currents (ID) by inducing a catalytic precipitation reaction. Variations in ID confer a sensitive discrimination of glucose enantiomers with a limit of detection (LOD) of 0.07 µM for L-Glu and 0.05 µM for D-Glu. This enantiomer-driven gate electrode response strategy not only provides a new route for enantiomer identification, but also helps to understand the origin of the high stereoselectivity in living systems.


Subject(s)
Biosensing Techniques , Electrochemical Techniques , Glucose , Gold , Hydrogen Peroxide , Limit of Detection , Metal Nanoparticles , Metal-Organic Frameworks , Metal-Organic Frameworks/chemistry , Biosensing Techniques/instrumentation , Gold/chemistry , Electrochemical Techniques/instrumentation , Stereoisomerism , Metal Nanoparticles/chemistry , Glucose/analysis , Glucose/chemistry , Glucose/isolation & purification , Hydrogen Peroxide/chemistry , Hydrogen Peroxide/analysis , Titanium/chemistry , Transistors, Electronic , Copper/chemistry , Light , Monosaccharides/analysis , Monosaccharides/chemistry , Nanotubes/chemistry
5.
J Phys Chem Lett ; 15(20): 5543-5548, 2024 May 23.
Article in English | MEDLINE | ID: mdl-38752860

ABSTRACT

Protein dynamics display distinct traits that are linked to their specific biological function. However, the interplay between intrinsic dynamics and the molecular environment on protein stability remains poorly understood. In this study, we investigate, by incoherent neutron scattering, the subnanosecond time scale dynamics of three model proteins: the mesophilic lysozyme, the thermophilic thermolysin, and the intrinsically disordered ß-casein. Moreover, we address the influence of water, glycerol, and glucose, which create progressively more viscous matrices around the protein surface. By comparing the protein thermal fluctuations, we find that the internal dynamics of thermolysin are less affected by the environment compared to lysozyme and ß-casein. We ascribe this behavior to the protein dynamic personality, i.e., to the stiffer dynamics of the thermophilic protein that contrasts the influence of the environment. Remarkably, lysozyme and thermolysin in all molecular environments reach a critical common flexibility when approaching the calorimetric melting temperature.


Subject(s)
Caseins , Muramidase , Thermolysin , Muramidase/chemistry , Muramidase/metabolism , Thermolysin/chemistry , Thermolysin/metabolism , Caseins/chemistry , Glycerol/chemistry , Water/chemistry , Glucose/chemistry , Neutron Diffraction , Molecular Dynamics Simulation
6.
Carbohydr Res ; 540: 109139, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38728964

ABSTRACT

The chemistry of N,N-diglycated amino acids remains unexplored due to their transient nature in the Maillard reaction. Their increased reactivity is attributed to the presence of high concentrations of open ring forms in at least one of their sugar moieties. The N,N-diglycated alanine derivatives were generated in situ via dissociation from their stable precursors the bis[N,N-diglycated alanine]iron(II) complexes, in the alanine/glucose/FeCl2 model system heated at 110 °C for 2 h. The thermal degradations of these complexes were followed in the reaction mixture, using isotope-labelled reactants, such as [13C-3] alanine and [13C-U] glucose, and ESI/qTOF/MS analysis. The N,N-diglycated amino acids exhibited a unique and characteristic chemical interaction between the neighbouring sugar moieties generating hitherto unknown heterocyclic moieties. The origin of these products was tracked by identifying ions incorporating one C-3 atom from alanine and between seven to 12 carbon atoms from the sugar moieties in the same structure. Temperature-dependent FTIR spectra of di-glycated alanine generated through ball milling provided further evidence for their reactivity.


Subject(s)
Alanine , Alanine/chemistry , Glycosylation , Maillard Reaction , Glucose/chemistry
7.
Int J Biol Macromol ; 268(Pt 2): 131724, 2024 May.
Article in English | MEDLINE | ID: mdl-38653427

ABSTRACT

The emergence of novel well-defined biological macromolecular architectures containing fluorine moieties displaying superior functionalities can satisfactorily address many biomedical challenges. In this research, ABA- and AB-type glucose-based biological macromolecules were synthesized using acryl-2,3,4,6-tetra-O-acetyl-D-glucopyranoside with pentafluorophenyl (FPM), pentafluorobenzyl (FBM), phenyl (PM) and benzyl (BM) methacrylate-based macro-RAFT agents following RAFT polymerization. The macro-RAFT agents and the corresponding copolymers were characterized by 19F, 1H, and 13C NMR and FTIR spectroscopic techniques to understand the chemical structure, molecular weight by size-exclusion chromatography, thermal analysis by TGA and DSC. Thermal stability (Td5%) of the FPM and FBM fluoro-based polymers was observed in the range of 219-267 °C, while the non-fluoro PM and BM polymers exhibited in the range of 216-264 °C. Among the macro-RAFT agents, PFPM (107 °C, ΔH: 0.613 J/g) and PPM (103 °C, ΔH: 0.455 J/g) showed higher Tm values, while among the block copolymers, PFBM-b-PG (123 °C, ΔH: 0.412 J/g) and PG-b-PFPM-b-PG (126 °C, ΔH: 0.525 J/g) exhibited higher Tm values. PFBMT and PPM macro-RAFT agents, PPM-b-PG and PG-b-PPM-b-PG copolymer spin-coated films showed the highest hydrophobicity (120°) among the synthesized polymers. The block copolymers exhibited self-assembled segregation by using relatively hydrophobic segments as the core and hydrophilic moieties as the corona. Synthesized biological macromolecules exhibit maximum antibacterial activity towards S. aureus than E. coli bacteria. Fluorophenyl (PFPM) and non-fluorobenzyl-based (PBMT) macro-RAFT agents exhibit low IC50 values, suggesting high cytotoxicity. All the triblock copolymers exhibit lesser cytotoxicity than the di-block polymers.


Subject(s)
Glucose , Macromolecular Substances , Glucose/chemistry , Macromolecular Substances/chemistry , Macromolecular Substances/chemical synthesis , Macromolecular Substances/pharmacology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/chemical synthesis , Polymers/chemistry , Polymers/chemical synthesis , Polymers/pharmacology , Humans , Polymerization , Molecular Weight , Fluorine/chemistry , Chemistry Techniques, Synthetic
8.
ACS Sens ; 9(5): 2634-2644, 2024 May 24.
Article in English | MEDLINE | ID: mdl-38669562

ABSTRACT

Gestational diabetes mellitus (GDM) is one of the most common metabolic disorders during pregnancy, leading to serious complications for pregnant women and a threat to life safety of infants. Therefore, it is particularly important to establish a multipurpose monitoring pathway to important physiological indicators of pregnant women. In this work, three kinds of double network hydrogels are prepared with poly(vinyl alcohol) (PVA), borax, and cellulose ethers with varying substituents of methyl (methyl cellulose, MC), hydroxypropyl (hydroxypropyl cellulose, HPC), or both (hydroxypropyl methyl cellulose, HPMC), respectively. The corresponding toughness (143.9, 102.3, and 135.9 kJ cm-3) and conductivity (0.69, 0.45, and 0.51 S m-1) of the hydrogels demonstrate that PB-MC was endowed with the prominent performance. Molecular dynamics simulations further revealed the essence that hydrogen bond interactions between PVA and cellulose ethers play a critical role in regulating the structure and properties of hydrogels. Thermochromic capsule powders (TCPs) were subsequently doped in to achieve a composite hydrogel (TCPs@PB-MC) to indicate the change in human body temperature. Furthermore, the process of the TCPs@PB-MC response to glucose, pH, and temperature was tracked in-depth through the electrochemical window. This work provides a novel strategy for all-in-one health management of GDM.


Subject(s)
Cellulose , Diabetes, Gestational , Hydrogels , Polyvinyl Alcohol , Female , Pregnancy , Humans , Hydrogels/chemistry , Cellulose/chemistry , Cellulose/analogs & derivatives , Polyvinyl Alcohol/chemistry , Borates/chemistry , Wearable Electronic Devices , Glucose/chemistry , Molecular Dynamics Simulation , Temperature , Hydrogen-Ion Concentration , Hydrogen Bonding
9.
Talanta ; 274: 126042, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38583326

ABSTRACT

This work emphasizes the utilization of biochar, a renewable material, as an interesting platform for anchoring redox mediators and bioreceptors in the development of economic, environmentally friendly biosensors. In this context, Fe(III) ions were preconcentrated on highly functionalized activated biochar, allowing the stable synthesis of Prussian blue nanostructures with an average size of 58.3 nm. The determination of glucose was carried out by indirectly monitoring the hydrogen peroxide generated through the enzymatic reaction, followed by its subsequent redox reaction with reduced Prussian blue (also known as Prussian white) in a typical electrochemical-chemical mechanism. The EDC/NHS (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-Hydroxysuccinimide) pair was employed for the stable covalent immobilization of the enzyme on biochar. The biosensor demonstrated good enzyme-substrate affinity, as evidenced by the Michaelis-Menten apparent kinetic constant (4.16 mmol L-1), and analytical performance with a wide linear dynamic response range (0.05-5.0 mmol L-1), low limits of detection (0.94 µmol L-1) and quantification (3.13 µmol L-1). Additionally, reliable repeatability, reproducibility, stability, and selectivity were obtained for the detection of glucose in both real and spiked human saliva and blood serum samples.


Subject(s)
Biosensing Techniques , Charcoal , Ferrocyanides , Glucose , Nanostructures , Ferrocyanides/chemistry , Biosensing Techniques/methods , Nanostructures/chemistry , Charcoal/chemistry , Glucose/analysis , Glucose/chemistry , Humans , Enzymes, Immobilized/chemistry , Glucose Oxidase/chemistry , Glucose Oxidase/metabolism , Blood Glucose/analysis , Hydrogen Peroxide/chemistry , Hydrogen Peroxide/analysis , Limit of Detection
10.
Bioresour Technol ; 400: 130667, 2024 May.
Article in English | MEDLINE | ID: mdl-38583674

ABSTRACT

Due to the complexity of biomass structures, the conversion of raw biomass into value-added chemicals is challenging and often requires efficient pretreatment of the biomass. In this paper, a simple and green pre-oxidation method, which was conducted under the conditions of 2 wt% H2O2, 80 min, and 150 °C, was reported to significantly increase the production of levoglucosan (LG) from biomass pyrolysis. The result showed that the LG yield significantly increased from 2.3 wt% (without pre-oxidation) to 23.1 wt% when pine wood was employed as a sample for pyrolysis at 400 °C, resulting from the removal of hemicellulose fraction and the in-situ acid catalysis of lignin carboxyl groups formed during the pre-oxidation. When the conditions for pre-oxidation became harsher than the above, the LG yield reduced because the decomposition of cellulose fraction in biomass. The study supplies an effective method for utilization of biomass as chemicals.


Subject(s)
Biomass , Glucose , Glucose/analogs & derivatives , Hydrogen Peroxide , Oxidation-Reduction , Pyrolysis , Hydrogen Peroxide/chemistry , Glucose/chemistry , Wood/chemistry , Pinus/chemistry , Lignin/chemistry , Lignin/analogs & derivatives
11.
Bioprocess Biosyst Eng ; 47(6): 919-929, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38644439

ABSTRACT

The growing need in the current market for innovative solutions to obtain lactose-free (L-F) milk is caused by the annual increase in the prevalence of lactose intolerance inside as well as the newborn, children, and adults. Various configurations of enzymes can yield two distinct L-F products: sweet (ß-galactosidase) and unsweet (ß-galactosidase and glucose oxidase) L-F milk. In addition, the reduction of sweetness through glucose decomposition should be performed in a one-pot mode with catalase to eliminate product inhibition caused by H2O2. Both L-F products enjoy popularity among a rapidly expanding group of consumers. Although enzyme immobilization techniques are well known in industrial processes, new carriers and economic strategies are still being searched. Polymeric carriers, due to the variety of functional groups and non-toxicity, are attractive propositions for individual and co-immobilization of food enzymes. In the presented work, two strategies (with free and immobilized enzymes; ß-galactosidase NOLA, glucose oxidase from Aspergillus niger, and catalase from Serratia sp.) for obtaining sweet and unsweet L-F milk under low-temperature conditions were proposed. For free enzymes, achieving the critical assumption, lactose hydrolysis and glucose decomposition occurred after 1 and 4.3 h, respectively. The tested catalytic membranes were created on regenerated cellulose and polyamide. In both cases, the time required for lactose and glucose bioconversion was extended compared to free enzymes. However, these preparations could be reused for up to five (ß-galactosidase) and ten cycles (glucose oxidase with catalase).


Subject(s)
Enzymes, Immobilized , Glucose Oxidase , Lactose , Milk , beta-Galactosidase , beta-Galactosidase/metabolism , beta-Galactosidase/chemistry , Milk/chemistry , Lactose/metabolism , Lactose/chemistry , Glucose Oxidase/chemistry , Glucose Oxidase/metabolism , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism , Animals , Aspergillus niger/enzymology , Glucose/metabolism , Glucose/chemistry , Catalase/metabolism , Catalase/chemistry , Membranes, Artificial
12.
Chem Commun (Camb) ; 60(40): 5302-5305, 2024 May 14.
Article in English | MEDLINE | ID: mdl-38661549

ABSTRACT

Although structural information on sugars is wide, experimental studies on the oxidation products of sugars in the gas phase, free from solvent interactions, have been rarely reported. We present an experimental work on the changes in the structure and interactions of two products of glucose oxidation (D-glucono-1,5-lactone (GlcL) and D-glucurono-6,3-lactone (GlcurL)) with respect to their precursor. Features such as intramolecular interactions, ring puckering and tautomerism were observed.


Subject(s)
Gluconates , Glucose , Lactones , Oxidation-Reduction , Glucose/chemistry , Lactones/chemistry , Gluconates/chemistry , Molecular Structure
13.
Nanoscale Horiz ; 9(6): 976-989, 2024 May 29.
Article in English | MEDLINE | ID: mdl-38568029

ABSTRACT

Single-atom nanozymes with well-defined atomic structures and electronic coordination environments can effectively mimic the functions of natural enzymes. However, the costly and intricate preparation processes have hindered further exploration and application of these single-atom nanozymes. In this study, we presented a synthesis technique for creating Fe-N central single-atom doped graphene quantum dot (FeN/GQDs) nanozymes using a one-step solvothermal process, where individual iron atoms form strong bonds with graphene quantum dots through nitrogen coordination. Unlike previous studies, this method significantly simplifies the synthesis conditions for single-atom nanozymes, eliminating the need for high temperatures and employing environmentally friendly precursors derived from pineapple (ananas comosus) leaves. The resulting FeN/GQDs exhibited peroxidase-like catalytic activity and kinetics comparable to that of natural enzymes, efficiently converting H2O2 into hydroxyl radical species. Leveraging their excellent peroxide-like activity, FeN/GQDs nanozymes have been successfully applied to construct a colorimetric biosensor system characterized by remarkably high sensitivity for glucose detection. This achievement demonstrated a promising approach to designing single-atom nanozymes with both facile synthesis procedures and high catalytic activity, offering potential applications in wearable sensors and personalized health monitoring.


Subject(s)
Biosensing Techniques , Glucose , Graphite , Green Chemistry Technology , Hydrogen Peroxide , Iron , Quantum Dots , Quantum Dots/chemistry , Graphite/chemistry , Iron/chemistry , Glucose/analysis , Glucose/chemistry , Biosensing Techniques/methods , Green Chemistry Technology/methods , Hydrogen Peroxide/chemistry , Hydrogen Peroxide/analysis , Colorimetry/methods , Catalysis , Humans
14.
J Chem Inf Model ; 64(9): 3841-3854, 2024 May 13.
Article in English | MEDLINE | ID: mdl-38635679

ABSTRACT

A series of atomistic molecular dynamics (MD) simulations were carried out with a hydrated 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) bilayer with the variation of glucose concentrations from 0 to 30 wt % in the presence of 0.3 M NaCl. The study suggested that although the thickness of the lipid bilayer dropped significantly with the increase in glucose concentration, it expanded laterally at high glucose levels due to the intercalation of glucose between the headgroups of adjacent lipids. We adopted the surface assessment via the grid evaluation method to compute the deviation of the bilayer's key structural features for the different amounts of glucose present. This suggested that the accumulation of glucose molecules near the headgroups influences the local lipid bilayer undulation and crimping of the lipid tails. We find that the area compressibility modulus increases with the glucose level, causing enhanced bilayer rigidity arising from the slow lateral diffusion of lipids. The restricted lipid motion at high glucose concentrations controls the sustainability of the curved bilayer surface. Calculations revealed that certain orientations of CO→ of interfacial glucose with the PN→ of lipid headgroups are preferred, which helps the glucose to form direct hydrogen bonds (HBs) with the lipid headgroups. Such lipid-glucose (LG) HBs relax slowly at low glucose concentrations and exhibit a higher lifetime, whereas fast structural relaxation of LG HBs with a shorter lifetime was noticed at a higher glucose level. In contrast, lipid-water (LW) HBs exhibited a higher lifetime at a higher glucose level, which gradually decreased with the glucose level lowering. The study interprets that the glucose concentration-driven LW and LG interactions are mutually inclusive. Our detailed analysis will exemplify small saccharide concentration-driven membrane stabilizing efficiency, which is, in general, helpful for drug delivery study.


Subject(s)
Dimyristoylphosphatidylcholine , Glucose , Lipid Bilayers , Molecular Dynamics Simulation , Water , Lipid Bilayers/chemistry , Glucose/chemistry , Dimyristoylphosphatidylcholine/chemistry , Water/chemistry
15.
Int J Biol Macromol ; 267(Pt 1): 131471, 2024 May.
Article in English | MEDLINE | ID: mdl-38599419

ABSTRACT

The conversion of glucose into fructose can transform cellulose into high-value chemicals. This study introduces an innovative synthesis method for creating an MgO-based ordered mesoporous carbon (MgO@OMC) catalyst, aimed at the efficient isomerization of glucose into fructose. Throughout the synthesis process, lignin serves as the exclusive carbon precursor, while Mg2+ functions as both a crosslinking agent and a metallic active center. This enables a one-step synthesis of MgO@OMC via a solvent-induced evaporation self-assembly (EISA) method. The synthesized MgO@OMCs exhibit an impeccable 2D hexagonal ordered mesoporous structure, in addition to a substantial specific surface area (378.2 m2/g) and small MgO nanoparticles (1.52 nm). Furthermore, this catalyst was shown active, selective, and reusable in the isomerization of glucose to fructose. It yields 41 % fructose with a selectivity of up to 89.3 % at a significant glucose loading of 7 wt% in aqueous solution over MgO0.5@OMC-600. This performance closely rivals the current maximum glucose isomerization yield achieved with solid base catalysts. Additionally, the catalyst retains a fructose selectivity above 60 % even after 4 cycles, a feature attributable to its extended ordered mesoporous structure and the spatial confinement effect of the OMCs, bestowing it with high catalytic efficiency.


Subject(s)
Carbon , Fructose , Glucose , Lignin , Magnesium Oxide , Fructose/chemistry , Lignin/chemistry , Glucose/chemistry , Carbon/chemistry , Porosity , Magnesium Oxide/chemistry , Catalysis , Isomerism
16.
Biosens Bioelectron ; 257: 116310, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-38643549

ABSTRACT

Nanozymes have been widely used in the field of biosensing owing to their high stability, low cost, adjustable catalytic activity, and convenient modification. However, achieving high selectivity and sensitivity simultaneously in nanozyme-based colorimetric sensing remains a major challenge. Nanozymes are nanomaterials with enzyme-simulating activity that are often used as solid-phase adsorbents for sample pretreatment. Our design strategy integrated sample pretreatment function into the nanozyme through separation and enrichment, thereby improving the selectivity and sensitivity of nanozyme-based colorimetric biosensing. As a proof-of-concept, glucose was used as the model analyte in this study. A phenylboric acid-modified magnetic nanozyme (Cu/Fe3O4@BA) was rationally designed and synthesized. Selectivity was enhanced by boronate-affinity specific adsorption and the elimination of interference after magnetic separation. In addition, magnetic solid-phase extraction enrichment was used to improve the sensitivity. A recovery rate of more than 80% was reached when the enrichment factor was 50. The synthesized magnetic Cu/Fe3O4@BA was recyclable at least five times. The proposed method exhibited excellent selectivity and sensitivity, simple operation, and recyclability, providing a novel and practical strategy for designing multifunctional nanozymes for biosensing.


Subject(s)
Biosensing Techniques , Colorimetry , Copper , Glucose , Biosensing Techniques/methods , Colorimetry/methods , Copper/chemistry , Glucose/analysis , Glucose/isolation & purification , Glucose/chemistry , Nanostructures/chemistry , Limit of Detection , Solid Phase Extraction/methods , Boronic Acids/chemistry , Adsorption
17.
J Chromatogr A ; 1722: 464874, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38598893

ABSTRACT

Hydroxypropyl methyl cellulose (HPMC) is a type of cellulose derivative with properties that render it useful in e.g. food, cosmetics, and pharmaceutical industry. The substitution degree and composition of the ß-glucose subunits of HPMC affect its physical and functional properties, but HPMC characterization is challenging due to its high structural heterogeneity, including many isomers. In this study, comprehensive two-dimensional liquid chromatography-mass spectrometry was used to examine substituted glucose monomers originating from complete acid hydrolysis of HPMC. Resolution between the different monomers was achieved using a C18 and cyano column in the first and second LC dimension, respectively. The data analysis process was structured to obtain fingerprints of the monomers of interest. The results revealed that isomers of the respective monomers could be selectively separated based on the position of substituents. The examination of two industrial HPMC products revealed differences in overall monomer composition. While both products contained monomers with a similar degree of substitution, they exhibited distinct regioselectivity.


Subject(s)
Hypromellose Derivatives , Mass Spectrometry , Hydrolysis , Hypromellose Derivatives/chemistry , Mass Spectrometry/methods , Chromatography, Liquid/methods , Isomerism , Glucose/chemistry , Glucose/analysis , Liquid Chromatography-Mass Spectrometry
18.
Biosensors (Basel) ; 14(3)2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38534241

ABSTRACT

Two types of low-cost reagentless electrochemical glucose biosensors based on graphite rod (GR) electrodes were developed. The electrodes modified with electrochemically synthesized platinum nanostructures (PtNS), 1,10-phenanthroline-5,6-dione (PD), glucose oxidase (GOx) without and with a polypyrrole (Ppy) layer-(i) GR/PtNS/PD/GOx and (ii) GR/PtNS/PD/GOx/Ppy, respectively, were prepared and tested. Glucose biosensors based on GR/PtNS/PD/GOx and GR/PtNS/PD/GOx/Ppy electrodes were characterized by the sensitivity of 10.1 and 5.31 µA/(mM cm2), linear range (LR) up to 16.5 and 39.0 mM, limit of detection (LOD) of 0.198 and 0.561 mM, good reproducibility, and storage stability. The developed glucose biosensors based on GR/PtNS/PD/GOx/Ppy electrodes showed exceptional resistance to interfering compounds and proved to be highly efficient for the determination of glucose levels in blood serum.


Subject(s)
Biosensing Techniques , Nanostructures , Glucose/chemistry , Polymers/chemistry , Pyrroles/chemistry , Platinum , Reproducibility of Results , Electrodes , Glucose Oxidase/chemistry , Enzymes, Immobilized/chemistry
19.
J Am Chem Soc ; 146(12): 7963-7970, 2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38483110

ABSTRACT

Cellulose serves as a sustainable biomaterial for a wide range of applications in biotechnology and materials science. While chemical and enzymatic glycan assembly methods have been developed to access modest quantities of synthetic cellulose for structure-property studies, chemical polymerization strategies for scalable and well-controlled syntheses of cellulose remain underdeveloped. Here, we report the synthesis of precision cellulose via living cationic ring-opening polymerization (CROP) of glucose 1,2,4-orthopivalates. In the presence of dibutyl phosphate as an initiator and triflic acid as a catalyst, precision cellulose with well-controlled molecular weights, defined chain-end groups, and excellent regio- and stereospecificity was readily prepared. We further demonstrated the utility of this method through the synthesis of precision native d-cellulose and rare precision l-cellulose.


Subject(s)
Cellulose , Glucose , Cellulose/chemistry , Polymerization , Glucose/chemistry , Polysaccharides , Cations
20.
Food Chem ; 447: 139018, 2024 Jul 30.
Article in English | MEDLINE | ID: mdl-38503067

ABSTRACT

Developing an accurate, cost-effective, reliable, and stable glucose detection sensor for the food industry poses a significant yet challenging endeavor. Herein, we present a silver nanoparticle-decorated titanium dioxide nanoribbon array on titanium plate (Ag@TiO2/TP) as an efficient electrode for non-enzymatic glucose detection in alkaline environments. Electrochemical evaluations of the Ag@TiO2/TP electrode reveal a broad linear response range (0.001 mM - 4 mM), high sensitivity (19,106 and 4264 µA mM-1 cm-2), rapid response time (6 s), and a notably low detection limit (0.18 µM, S/N = 3). Moreover, its efficacy in measuring glucose in beverage samples shows its practical applicability. The impressive performance and structural benefits of the Ag@TiO2/TP electrode highlight its potential in advancing electrochemical sensors for small molecule detection.


Subject(s)
Biosensing Techniques , Metal Nanoparticles , Nanotubes, Carbon , Metal Nanoparticles/chemistry , Electrochemical Techniques , Silver , Glucose/chemistry , Electrodes
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