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1.
Food Chem ; 451: 139427, 2024 Sep 01.
Article in English | MEDLINE | ID: mdl-38692237

ABSTRACT

Here, we report a monomer planarity modulation strategy for room-temperature constructing molecularly imprinted-covalent organic frameworks (MI-COFs) for selective extraction of ochratoxin A (OTA). 2,4,6-triformylphloroglucinol (Tp) was used as basic building block, while three amino monomers with different planarity were employed as modulators to explore the effect of planarity on the selectivity of MI-COFs. The MI-TpTapa constructed from Tp and the lowest planarity of monomer Tapa gave the highest selectivity for OTA, and was further used as the adsorbent for dispersed-solid phase extraction (DSPE) of OTA in alcohol samples. Coupling MI-TpTapa based DSPE with high-performance liquid chromatography allowed the matrix-effect free determination of OTA in alcohol samples with the limit of detection of 0.023 µg kg-1 and the recoveries of 91.4-97.6%. The relative standard deviation (RSD, n = 6) of intra and inter day was <3.2%. This work provides a new way to construct MI-COFs for selective extraction of hazardous targets.


Subject(s)
Food Contamination , Molecular Imprinting , Ochratoxins , Solid Phase Extraction , Ochratoxins/analysis , Ochratoxins/isolation & purification , Ochratoxins/chemistry , Solid Phase Extraction/methods , Solid Phase Extraction/instrumentation , Chromatography, High Pressure Liquid , Food Contamination/analysis , Adsorption , Alcohols/chemistry , Alcohols/isolation & purification , Metal-Organic Frameworks/chemistry
2.
Pharm Res ; 41(5): 983-1006, 2024 May.
Article in English | MEDLINE | ID: mdl-38561580

ABSTRACT

OBJECTIVE: This research aims to elucidate critical impurities in process validation batches of tacrolimus injection formulations, focusing on identification and characterization of previously unreported impurity at RRT 0.42, identified as the tacrolimus alcohol adduct. The potential root causes for the formation of new impurity was determined using structured risk assessment by cause and effect fishbone diagram. The primary objective was to propose mitigation plan and demonstrate the control of impurities with 6 month accelerated stability results in development batches. METHODS: The investigation utilizes method validation and characterization studies to affirm the accuracy of quantifying the tacrolimus alcohol adduct. The research methodology employed different characterization techniques like rotational rheometer, ICP‒MS, MALDI-MS, 1H NMR, 13C NMR, and DEPT-135 NMR for structural elucidation. Additionally, the exact mass of the impurity is validated using electrospray ionization mass spectra. RESULTS: Results indicate successful identification and characterization of the tacrolimus alcohol adduct. The study further explores the transformation of Tacrolimus monohydrate under various conditions, unveiling the formation of Tacrolimus hydroxy acid and proposing the existence of a novel degradation product, the Tacrolimus alcohol adduct. Six-month data from development lots utilizing Manufacturing Process II demonstrate significantly lower levels of alcohol adducts. CONCLUSIONS: Manufacturing Process II, selectively locates Tacrolimus within the micellar core of HCO-60, this prevent direct contact of ethanol with Tacrolimus which minimizes impurity alcohol adduct formation. This research contributes to the understanding of tacrolimus formulations, offering ways to safeguard product integrity and stability during manufacturing and storage.


Subject(s)
Drug Contamination , Immunosuppressive Agents , Tacrolimus , Drug Contamination/prevention & control , Tacrolimus/chemistry , Tacrolimus/analysis , Immunosuppressive Agents/chemistry , Immunosuppressive Agents/analysis , Drug Stability , Alcohols/chemistry , Alcohols/analysis , Drug Compounding/methods , Magnetic Resonance Spectroscopy/methods
3.
J Phys Chem B ; 128(17): 4076-4086, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38642057

ABSTRACT

In aqueous binary solvents with fluorinated alcohols, 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), and aliphatic alcohols, ethanol (EtOH) and 2-propanol (2-PrOH), the denaturation of hen egg white lysozyme (HEWL) with increasing alcohol mole fraction xA has been investigated in a wide view from the molecular vibration to the secondary and ternary structures. Circular dichroism (CD) measurement showed that the secondary structure of α-helix content of HEWL increases on adding a small amount of the fluorinated alcohol to the aqueous solution, while the ß-sheet content decreases. On the contrary, the secondary structure does not significantly change by the addition of the aliphatic alcohols. Correspondingly, the infrared (IR) spectroscopic measurements revealed that the amide I band red-shifts on the addition of the fluorinated alcohol. However, the band remains unchanged in the aliphatic alcohol systems with increasing alcohol content. To observe the ternary structure of HEWL, small-angle neutron scattering (SANS) experiments with H/D substitution technique have been applied to the HEWL solutions. The SANS experiments were successful in revealing the details of how the geometry of the HEWL changes as a function of xA. The SANS profiles indicated the spherical structure of HEWL in all of the alcohol systems in the xA range examined. The mean radius of HEWL in the two fluorinated alcohol systems increases from ∼16 to ∼18 Å during the change in the secondary structure against the increase in the fluorinated alcohol content. On contrast, the radius does not significantly change in both aliphatic alcohol systems below xA = 0.3 but expands to ∼19 Å as the alcohol content is close to the limitation of the HEWL solubility. According to the present results, together with our knowledge of the alcohol cluster formation and the interaction of the trifluoromethyl (CF3) groups with the hydrophobic moieties of biomolecules, the effects of alcohols on the denaturation of the protein have been discussed on a molecular scale.


Subject(s)
Circular Dichroism , Muramidase , Protein Denaturation , Scattering, Small Angle , Muramidase/chemistry , Muramidase/metabolism , Animals , Neutron Diffraction , Spectrophotometry, Infrared , Chickens , Alcohols/chemistry
4.
Int J Mol Sci ; 25(8)2024 Apr 11.
Article in English | MEDLINE | ID: mdl-38673827

ABSTRACT

We report a study on the hydrogen bonding mechanisms of three aliphatic alcohols (2-propanol, methanol, and ethanol) and one diol (ethylene glycol) in water solution using a time-domain ellipsometer in the THz region. The dielectric response of the pure liquids is nicely modeled by the generalized Debye-Lorentz equation. For binary mixtures, we analyze the data using a modified effective Debye model, which considers H-bond rupture and reformation dynamics and the motion of the alkyl chains and of the OH groups. We focus on the properties of the water-rich region, finding anomalous behavior in the absorption properties at very low solute molar concentrations. These results, first observed in the THz region, are in line with previous findings from different experiments and can be explained by taking into account the amphiphilic nature of the alcohol molecules.


Subject(s)
Alcohols , Hydrogen Bonding , Water , Water/chemistry , Alcohols/chemistry , Terahertz Spectroscopy/methods , Ethanol/chemistry , 2-Propanol/chemistry
5.
Molecules ; 29(7)2024 Mar 28.
Article in English | MEDLINE | ID: mdl-38611800

ABSTRACT

4-Chloroisocoumarin compounds have broad inhibitory properties against serine proteases. Here, we show that selected 3-alkoxy-4-chloroisocoumarins preferentially inhibit the activity of the conserved serine protease High-temperature requirement A of Chlamydia trachomatis. The synthesis of a new series of isocoumarin-based scaffolds has been developed, and their anti-chlamydial properties were investigated. The structure of the alkoxy substituent was found to influence the potency of the compounds against High-temperature requirement A, and modifications to the C-7 position of the 3-alkoxy-4-chloroisocoumarin structure attenuate anti-chlamydial properties.


Subject(s)
Alcohols , Chlamydia trachomatis , Protease Inhibitors , Protease Inhibitors/pharmacology , Enzyme Therapy , Isocoumarins , Serine Endopeptidases , Serine Proteases
6.
J Agric Food Chem ; 72(11): 5766-5776, 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38447044

ABSTRACT

The aromatic amino acids tryptophan, phenylalanine, and tyrosine are targets for oxidation during food processing. We investigated whether S. cerevisiae can use nonproteinogenic aromatic amino acids as substrates for degradation via the Ehrlich pathway. The metabolic fate of seven amino acids (p-, o-, m-tyrosine, 3,4-dihydroxyphenylalanine (DOPA), 3-nitrotyrosine, 3-chlorotyrosine, and dityrosine) in the presence of S. cerevisiae was assessed. All investigated amino acids except dityrosine were metabolized by yeast. The amino acids 3-nitrotyrosine and o-tyrosine were removed from the medium as fast as p-tyrosine, and m-tyrosine, 3-chlorotyrosine, and DOPA more slowly. In summary, 11 metabolites were identified by high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS). DOPA, 3-nitrotyrosine, and p-tyrosine were metabolized predominantly to the Ehrlich alcohols, whereas o-tyrosine and m-tyrosine were metabolized predominantly to α-hydroxy acids. Our results indicate that nonproteinogenic aromatic amino acids can be taken up and transaminated by S. cerevisiae quite effectively but that decarboxylation and reduction to Ehrlich alcohols as the final metabolites is hampered by hydroxyl groups in the o- or m-positions of the phenyl ring. The data on amino acid metabolism were substantiated by the analysis of five commercial beer samples, which revealed the presence of hydroxytyrosol (ca. 0.01-0.1 mg/L) in beer for the first time.


Subject(s)
Amino Acids, Aromatic , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolism , Amino Acids, Aromatic/metabolism , Tandem Mass Spectrometry , Tyrosine/metabolism , Amino Acids/metabolism , Dihydroxyphenylalanine/metabolism , Alcohols/metabolism
7.
Chem Pharm Bull (Tokyo) ; 72(3): 303-308, 2024.
Article in English | MEDLINE | ID: mdl-38479853

ABSTRACT

Amine-free phosphorylation of various alcohols was developed with 4-methylpyridine N-oxide in the presence of 4 Å molecular sieves at room temperature. This mild method gave various phosphorylated products in high yield and could be applied to acid- or base-sensitive substrates. Furthermore, this method was also effective for the chemoselective phosphorylation of diols or polyols.


Subject(s)
Alcohols , Oxides , Picolines , Amines , Phosphorylation , Catalysis
8.
Helicobacter ; 29(2): e13064, 2024.
Article in English | MEDLINE | ID: mdl-38459689

ABSTRACT

BACKGROUND: Helicobacter pylori (H. pylori) infection is the most extensively studied risk factor for gastric cancer. As with any bacteria, H. pylori will release distinctive odors that result from an emission of volatile metabolic byproducts in unique combinations and proportions. Effectively capturing and identifying these volatiles can pave the way for the development of innovative and non-invasive diagnostic methods for determining infection. Here we characterize the H. pylori volatilomic signature, pinpoint potential biomarkers of its presence, and evaluate the variability of volatilomic signatures between different H. pylori isolates. MATERIALS AND METHODS: Using needle trap extraction, volatiles in the headspace above H. pylori cultures were collected and, following thermal desorption at 290°C in a splitless mode, were analyzed using gas chromatography-mass spectrometry. The resulting volatilomic signatures of H. pylori cultures were compared to those obtained from an analysis of the volatiles in the headspace above the cultivating medium only. RESULTS: Amongst the volatiles detected, 21 showed consistent differences between the bacteria cultures and the cultivation medium, with 11 compounds being elevated and 10 showing decreased levels in the culture's headspace. The 11 elevated volatiles are four ketones (2-pentanone, 5-methyl-3-heptanone, 2-heptanone, and 2-nonanone), three alcohols (2-methyl-1-propanol, 3-methyl-1-butanol, and 1 butanol), one aromatic (styrene), one aldehyde (2-ethyl-hexanal), one hydrocarbon (n-octane), and one sulfur compound (dimethyl disulfide). The 10 volatiles with lower levels in the headspace of the cultures are four aldehydes (2-methylpropanal, benzaldehyde, 3-methylbutanal, and butanal), two heterocyclic compounds (2-ethylfuran and 2-pentylfuran), one ketone (2-butanone), one aromatic (benzene), one alcohol (2-butanol) and bromodichloromethane. Of the volatile species showing increased levels, the highest emissions are found to be for 3-methyl-1-butanol, 1-butanol and dimethyl disulfide. Qualitative variations in their emissions from the different isolates was observed. CONCLUSIONS: The volatiles emitted by H. pylori provide a characteristic volatilome signature that has the potential of being developed as a tool for monitoring infections caused by this pathogen. Furthermore, using the volatilome signature, we are able to differentiate different isolates of H. pylori. However, the volatiles also represent potential confounders for the recognition of gastric cancer volatile markers.


Subject(s)
Disulfides , Helicobacter Infections , Helicobacter pylori , Pentanols , Stomach Neoplasms , Humans , Alcohols
9.
Int J Mol Sci ; 25(6)2024 Mar 13.
Article in English | MEDLINE | ID: mdl-38542218

ABSTRACT

This study addresses the pressing issues of energy production and consumption, in line with global sustainable development goals. Focusing on the potential of alcohols as "green" alternatives to traditional fossil fuels, especially in biofuel applications, we investigate the thermochemical properties of three alcohols (n-propanol, n-butanol, n-pentanol) blended with sunflower oil. The calorimetric analysis allows for the experimental determination of excess enthalpies in pseudo-binary mixtures at 303.15 K, revealing similarities in the trends of the curves (dependence on concentrations) but with different values for the excess enthalpies for each mixture. Despite the structural differences of the alcohols studied, the molar excess enthalpy values exhibit uniformity, suggesting consistent mixing behavior. The peak values of excess enthalpies for systems with sunflower oil and n-propanol, n-butanol and n-pentanol are, respectively, 3255.2 J/mole, 3297.4 J/mole and 3150.1 J/mole. Both the NRTL and Redlich-Kister equations show satisfactory agreement with the obtained values.


Subject(s)
Alcohols , Biofuels , Pentanols , Alcohols/chemistry , Sunflower Oil , 1-Propanol , 1-Butanol
10.
Bioresour Technol ; 400: 130646, 2024 May.
Article in English | MEDLINE | ID: mdl-38556063

ABSTRACT

The present study evaluated the production potential of CH4, carboxylic acids and alcohols from a mixed culture enriched using synthetic syngas. The influence of syngas concentration on the microbial community and products productivity and selectivity was investigated. The results demonstrated the enrichment of a mesophilic mixed culture capable of converting CO and H2 mainly to CH4 and acetate, along with butyrate. The selectivity values showed that acetate production was enhanced during the first cycle in all conditions tested (up to 20 %), while CH4 was the main product generated during following cycles. Concretely, CH4 selectivity remained unaffected by syngas concentration, reaching a stable value of 41.6 ± 2.0 %. On the other hand, butyrate selectivity was only representative at the highest syngas concentration and lower pH values (26.1 ± 5.8 %), where the H2 consumption was completely inhibited. Thus, pH was identified as a key parameter for both butyrate synthesis and the development of hydrogenotrophic activity.


Subject(s)
Fatty Acids, Volatile , Methane , Methane/metabolism , Fatty Acids, Volatile/metabolism , Hydrogen-Ion Concentration , Hydrogen/metabolism , Gases/metabolism , Bioreactors , Alcohols/metabolism , Acetates/metabolism , Butyrates/metabolism
11.
J Hosp Infect ; 147: 206-212, 2024 May.
Article in English | MEDLINE | ID: mdl-38521416

ABSTRACT

BACKGROUND: Elderly nursing home residents are vulnerable to infection from micro-organisms. Hand hygiene is considered one of the most important measures to prevent transmission. AIM: To determine the effect of increased accessibility to alcohol-based hand rub (ABHR) in nursing home wards by monitoring hand hygiene compliance (HHC) among healthcare workers (HCWs). METHODS: An 11-month intervention study was conducted in a Danish six-ward nursing home. Data were collected using an automatic hand hygiene monitoring system (AHHMS). After a baseline period, one extra ABHR dispenser was placed in each of the 150 apartments. Baseline HHC was compared with the HHC during an immediate intervention period and a long-term intervention period. FINDINGS: A total of 159 HCWs were included. The AHHMS registered 341,078 hand hygiene opportunities. Overall baseline HHC was 31% (95% confidence interval: 30-32). A significant +18% absolute immediate effect (first five months) (95% CI: 17-19; P < 0.0001) and +13 percentage points (95% CI: 11-14; P < 0.0001) long-term effect (another four months) were recorded. HCWs working day shifts and short-term employees had a higher baseline HHC than HCWs working evening/night shifts. However, HCWs working night shifts achieved the greatest long-term effect with a mean +27 percentage point difference (P < 0.0001). CONCLUSION: Placing an additional ABHR dispenser strategically within staff workflow significantly increased HHC among HCWs, demonstrating a noteworthy effect. The study is the first to report the effect on nursing home dispenser accessibility as a single intervention and to show a significant unmet potential.


Subject(s)
Alcohols , Guideline Adherence , Hand Hygiene , Health Personnel , Nursing Homes , Humans , Guideline Adherence/statistics & numerical data , Denmark , Health Personnel/statistics & numerical data , Hand Hygiene/methods , Hand Hygiene/statistics & numerical data , Hand Hygiene/standards , Alcohols/administration & dosage , Infection Control/methods , Infection Control/standards , Female , Male , Cross Infection/prevention & control , Hand Disinfection/methods , Hand Disinfection/standards , Hand Sanitizers/administration & dosage , Aged
12.
New Phytol ; 242(5): 2251-2269, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38501480

ABSTRACT

The plant cuticle is a hydrophobic barrier, which seals the epidermal surface of most aboveground organs. While the cuticle biosynthesis of angiosperms has been intensively studied, knowledge about its existence and composition in nonvascular plants is scarce. Here, we identified and characterized homologs of Arabidopsis thaliana fatty acyl-CoA reductase (FAR) ECERIFERUM 4 (AtCER4) and bifunctional wax ester synthase/acyl-CoA:diacylglycerol acyltransferase 1 (AtWSD1) in the liverwort Marchantia polymorpha (MpFAR2 and MpWSD1) and the moss Physcomitrium patens (PpFAR2A, PpFAR2B, and PpWSD1). Although bryophyte harbor similar compound classes as described for angiosperm cuticles, their biosynthesis may not be fully conserved between the bryophytes M. polymorpha and P. patens or between these bryophytes and angiosperms. While PpFAR2A and PpFAR2B contribute to the production of primary alcohols in P. patens, loss of MpFAR2 function does not affect the wax profile of M. polymorpha. By contrast, MpWSD1 acts as the major wax ester-producing enzyme in M. polymorpha, whereas mutations of PpWSD1 do not affect the wax ester levels of P. patens. Our results suggest that the biosynthetic enzymes involved in primary alcohol and wax ester formation in land plants have either evolved multiple times independently or undergone pronounced radiation followed by the formation of lineage-specific toolkits.


Subject(s)
Waxes , Waxes/metabolism , Alcohols/metabolism , Phylogeny , Marchantia/genetics , Marchantia/metabolism , Plant Proteins/metabolism , Plant Proteins/genetics , Bryopsida/genetics , Bryopsida/metabolism , Bryophyta/genetics , Bryophyta/metabolism , Aldehyde Oxidoreductases/metabolism , Aldehyde Oxidoreductases/genetics , Biosynthetic Pathways/genetics , Evolution, Molecular , Gene Expression Regulation, Plant , Acyltransferases/metabolism , Acyltransferases/genetics , Biological Evolution , Arabidopsis/genetics , Arabidopsis/metabolism , Mutation/genetics
13.
Chem Soc Rev ; 53(9): 4607-4647, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38525675

ABSTRACT

Alcohol is ubiquitous with unparalleled structural diversity and thus has wide applications as a native functional group in organic synthesis. It is highly prevalent among biomolecules and offers promising opportunities for the development of chemical libraries. Over the last decade, alcohol has been extensively used as an environmentally friendly chemical for numerous organic transformations. In this review, we collectively discuss the utilisation of alcohol from 2015 to 2023 in various organic transformations and their application toward intermediates of drugs, drug derivatives and natural product-like molecules. Notable features discussed are as follows: (i) sustainable approaches for C-X alkylation (X = C, N, or O) including O-phosphorylation of alcohols, (ii) newer strategies using methanol as a methylating reagent, (iii) allylation of alkenes and alkynes including allylic trifluoromethylations, (iv) alkenylation of N-heterocycles, ketones, sulfones, and ylides towards the synthesis of drug-like molecules, (v) cyclisation and annulation to pharmaceutically active molecules, and (vi) coupling of alcohols with aryl halides or triflates, aryl cyanide and olefins to access drug-like molecules. We summarise the synthesis of over 100 drugs via several approaches, where alcohol was used as one of the potential coupling partners. Additionally, a library of molecules consisting over 60 fatty acids or steroid motifs is documented for late-stage functionalisation including the challenges and opportunities for harnessing alcohols as renewable resources.


Subject(s)
Alcohols , Alcohols/chemistry , Alcohols/chemical synthesis , Pharmaceutical Preparations/chemistry , Pharmaceutical Preparations/chemical synthesis , Biological Products/chemistry , Biological Products/chemical synthesis , Indicators and Reagents/chemistry , Alkylation , Molecular Structure , Alkenes/chemistry , Alkenes/chemical synthesis , Green Chemistry Technology
14.
Plant Signal Behav ; 19(1): 2331894, 2024 Dec 31.
Article in English | MEDLINE | ID: mdl-38516998

ABSTRACT

A bacterium growing on infected leaves of Hydrocotyle umbellata, commonly known as dollarweed, was isolated and identified as Pantoea ananatis. An ethyl acetate extract of tryptic soy broth (TSB) liquid culture filtrate of the bacterium was subjected to silica gel chromatography to isolate bioactive molecules. Indole was isolated as the major compound that gave a distinct, foul odor to the extract, together with phenethyl alcohol, phenol, tryptophol, N-acyl-homoserine lactone, 3-(methylthio)-1-propanol, cyclo(L-pro-L-tyr), and cyclo(dehydroAla-L-Leu). This is the first report of the isolation of cyclo(dehydroAla-L-Leu) from a Pantoea species. Even though tryptophol is an intermediate in the indoleacetic acid (IAA) pathway, we were unable to detect or isolate IAA. We investigated the effect of P. ananatis inoculum on the growth of plants. Treatment of Lemna paucicostata Hegelm plants with 4 × 109 colony forming units of P. ananatis stimulated their growth by ca. five-fold after 13 days. After 13 days of treatment, some control plants were browning, but treated plants were greener and no plants were browning. The growth of both Cucumis sativus (cucumber) and Sorghum bicolor (sorghum) plants was increased by ca. 20 to 40%, depending on the growth parameter and species, when the rhizosphere was treated with the bacterium after germination at the same concentration. Plant growth promotion by Pantoea ananatis could be due to the provision of the IAA precursor indole.


Subject(s)
Alcohols , Centella , Indoles , Pantoea , Pantoea/chemistry , Pantoea/metabolism , Plants/microbiology
15.
Nat Commun ; 15(1): 2523, 2024 Mar 21.
Article in English | MEDLINE | ID: mdl-38514642

ABSTRACT

Prostaglandins have garnered significant attention from synthetic chemists due to their exceptional biological activities. In this report, we present a concise chemoenzymatic synthesis method for several representative prostaglandins, achieved in 5 to 7 steps. Notably, the common intermediate bromohydrin, a radical equivalent of Corey lactone, is chemoenzymatically synthesized in only two steps, which allows us to complete the synthesis of prostaglandin F2α in five steps on a 10-gram scale. The chiral cyclopentane core is introduced with high enantioselectivity, while the lipid chains are sequentially incorporated through a cost-effective process involving bromohydrin formation, nickel-catalyzed cross-couplings, and Wittig reactions. This cost-efficient synthesis route for prostaglandins holds the potential to make prostaglandin-related drugs more affordable and facilitate easier access to their analogues.


Subject(s)
Alcohols , Prostaglandins , Prostaglandins/chemical synthesis
16.
Food Res Int ; 182: 114077, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38519167

ABSTRACT

Fruits flavor deterioration is extremely likely to occur during post-harvest storage, which not only damages quality but also seriously affects its market value. This work focuses on the study of fruits deterioration odorants during storage by describing their chemical compositions (i.e., alcohols, aldehydes, acids, and sulfur-containing compounds). Besides, the specific flavor deterioration mechanisms (i.e., fermentation metabolism, lipid oxidation, and amino acid degradation) inducing by factors (temperature, oxygen, microorganisms, ethylene) are summarized. Moreover, quality control strategies to mitigate fruits flavor deterioration by physical (temperature control, hypobaric treatment, UV-C, CA) and chemical (1-MCP, MT, NO, MeJA) techniques are also proposed. This review will provide useful references for fruits flavor control technologies development.


Subject(s)
Fruit , Odorants , Fruit/chemistry , Aldehydes/analysis , Alcohols/analysis , Fermentation
17.
Food Res Int ; 182: 114187, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38519195

ABSTRACT

The flavor profiles of fresh and aged fermented peppers obtained from four varieties were thoroughly compared in this study. A total of 385 volatile compounds in fermented pepper samples were detected by flavoromics (two-dimensional gas chromatography-time-of-flight mass spectrometry). As fermentation progressed, both the number and the total concentration of volatile compounds changed, with esters, alcohols, acids, terpenoids, sulfur compounds, and funans increasing, whereas hydrocarbons and benzenes decreased. In contrast to the fresh fermented peppers, the aged fermented samples exhibited lower values of pH, total sugars, and capsaicinoids but higher contents of organic acids and free amino acids. Furthermore, the specific differences and characteristic aroma substances among aged fermented peppers were unveiled by multivariate statistical analysis. Overall, 64 volatiles were screened as differential compounds. In addition, Huanggongjiao samples possessed the most abundant differential volatiles and compounds with odor activity values > 1, which were flavored with fruity, floral, and slightly phenolic odors. Correlation analysis demonstrated that the levels of 23 key aroma compounds (e.g., ethyl 2-methylbutyrate, 1-butanol, and ethyl valerate) showed a significantly positive correlation with Asp, Glu and 5 organic acids. By contrast, there is a negative association between the pH value and total sugar. Overall, aging contributed significantly to the flavor attributes of fermented peppers.


Subject(s)
Fruit , Piper nigrum , Fruit/chemistry , Odorants/analysis , Gas Chromatography-Mass Spectrometry/methods , Alcohols/analysis , Fermentation , Acids/analysis
18.
J Agric Food Chem ; 72(10): 5439-5451, 2024 Mar 13.
Article in English | MEDLINE | ID: mdl-38412221

ABSTRACT

Increasing hydrogen peroxide (H2O2)-based systems have been developed to degrade various polysaccharides due to the presence of highly reactive free radicals, but published degradation mechanisms are still limited. Therefore, this study aimed to clarify the degradation mechanism of six typical glucosidic bonds from different disaccharides in an ultraviolet (UV)/H2O2 system. The results showed that the H2O2 concentration, disaccharide concentration, and radiation intensity were important factors affecting pseudo-first-order kinetic constants. Hydroxyl radical, superoxide radical, and UV alone contributed 58.37, 18.52, and 19.17% to degradation, respectively. The apparent degradation rates ranked in the order of cellobiose ≈ lactose > trehalose ≈ isomaltose > turanose > sucrose ≈ maltose. The reaction pathways were then deduced after identifying their degradation products. According to quantum chemical calculations, the cleavage of α-glycosidic bonds was more kinetically unfavorable than that of ß-glycosidic bonds. Additionally, the order of apparent degradation rates depended on the energy barriers for the formation of disaccharide-based alkoxyl radicals. Moreover, energy barriers for homolytic scissions of glucosidic C1-O or C7-O sites of these alkoxyl radicals ranked in the sequence: α-(1 → 2) ≈ α-(1 → 3) < α-(1 → 4) < ß-(1 → 4) < α-(1 → 6) < α-(1 → 1) glucosidic bonds. This study helps to explain the mechanisms of carbohydrate degradation by free radicals.


Subject(s)
Alcohols , Hydrogen Peroxide , Water Pollutants, Chemical , Hydrogen Peroxide/chemistry , Glucosides , Disaccharides/chemistry , Maltose/metabolism , Sucrose/chemistry , Ultraviolet Rays , Oxidation-Reduction , Kinetics , Water Pollutants, Chemical/chemistry
19.
Biomacromolecules ; 25(3): 1709-1723, 2024 Mar 11.
Article in English | MEDLINE | ID: mdl-38377481

ABSTRACT

Polysaccharide nanoporous structures are suitable for various applications, ranging from biomedical scaffolds to adsorption materials, owing to their biocompatibility and large surface areas. Pectin, in particular, can create 3D nanoporous structures in aqueous solutions by binding with calcium cations and creating nanopores by phase separation; this process involves forming hydrogen bonds between alcohols and pectin chains in water and alcohol mixtures and the resulting penetration of alcohols into calcium-bound pectin gels. However, owing to the dehydration and condensation of polysaccharide chains during drying, it has proven to be challenging to maintain the 3D nanoporous structure without using a freeze-drying process or supercritical fluid. Herein, we report a facile method for creating polysaccharide-based xerogels, involving the co-evaporation of water with a nonsolvent (e.g., a low-molecular-weight hydrophobic alcohol such as isopropyl or n-propyl alcohol) at ambient conditions. Experiments and coarse-grained molecular dynamics simulations confirmed that salt-induced phase separation and hydrogen bonding between hydrophobic alcohols and pectin chains were the dominant processes in mixtures of pectin, water, and hydrophobic alcohols. Furthermore, the azeotropic evaporation of water and alcohol mixed in approximately 1:1 molar ratios was maintained during the natural drying process under ambient conditions, preventing the hydration and aggregation of the hydrophilic pectin chains. These results introduce a simple and convenient process to produce 3D polysaccharide xerogels under ambient conditions.


Subject(s)
Calcium , Nanopores , Calcium/chemistry , Pectins/chemistry , Phase Separation , Water/chemistry , Sodium Chloride , Alcohols/chemistry
20.
Chem Pharm Bull (Tokyo) ; 72(2): 213-219, 2024.
Article in English | MEDLINE | ID: mdl-38382974

ABSTRACT

Nucleophilic deprotection of p-methoxybenzyl (PMB) [p-methoxyphenylmethyl (MPM)] ethers was developed using a heterogeneous oxovanadium catalyst V-MPS4 and a thiol nucleophile. The deprotection method had a wide reaction scope, including PMB ethers of primary, secondary, and tertiary alcohols bearing various functional groups. In addition, the PMB ether of an oxidation-labile natural product was successfully removed by V-MPS4 catalysis, while a common oxidative method of PMB deprotection afforded a complex mixture. The V-MPS4 catalyst was reusable up to six times without a significant loss in the product yield. The advantages of using the heterogeneous catalyst were further demonstrated by conducting the deprotection reaction in a continuous flow process, which resulted in a 2.7-fold higher catalyst turnover number and 60-fold higher turnover frequency compared to those of the corresponding batch reaction.


Subject(s)
Ethers , Ethyl Ethers , Catalysis , Alcohols , Oxidation-Reduction
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