Detection of amino thiols from fish samples by stable isotope chemical labelling coupled with ultra-performance liquid chromatography-tandem mass spectrometry.

The amino thiols are key antioxidants in organisms, and their detection in food is of significant importance. This study developed a new stable isotope chemical labelling coupled with ultra-performance liquid chromatography-tandem mass spectrometry method to detect six amino thiols from fish samples. By the proposed method, amino thiols were labeled after liquid extraction using the stable isotope labeling reagents of iodoacetamide (IAM) and D-IAM.

Integrated Metabolomic and Transcriptomic Analysis Reveal the Production Mechanism of Semicarbazide in Under Urea Conditions.

Semicarbazide (SEM) is commonly utilized as a biomarker for detecting the usage of nitrofurazone (NFZ); however, its endogenous presence in aquatic products complicates detection and poses challenges to the quality and safety of these products. Although previous research suggests a potential link between SEM and urea, the specific mechanisms underlying its production under induced conditions remain unclear. To solve the above problem, the integrated metabolomic and transcriptomic analyses were performed for systematically exploring endogenous production mechanisms underlying SEM in under urea conditions.

Inhibition of Biogenic Amines in Fermented Tilapia Surimi by Collaborative Fermentation of and .

Fermentation is an effective method for ameliorating the gelation properties of freshwater fish surimi, but the formation of biogenic amines (BAs) during fermentation should also be controlled. In this study, the BAs in fermented tilapia surimi were inhibited by the collaborative fermentation of and , followed by the revelation of the BA inhibition mechanism. Most of the BAs, and the total BA, as well as their precusor free amino acids (FAAs), were significantly reduced, while the umami FAAs, including glutamic acid and aspartic acid, were significantly enhanced after cooperative fermentation with starters.

A case of hemorrhagic fever with renal syndrome and abnormal serum levels of ferritin, vitamin B12, and folic acid.

Introduction: Hemorrhagic fever with renal syndrome (HFRS) is a globally prevalent infectious disease caused by the hantavirus in rodents.

Case Study: This report describes a case of a 36-year-old male presenting with elevated ferritin, vitamin B12, and folic acid deficiency during the early onset phase of HFRS. Despite normal renal function at admission, the patient exhibited persistent fever and thrombocytopenia, leading to a potential misdiagnosis of an atypical HFRS presentation.

Effect of Accelerated Aging on Bamboo Fiber Lunch Box and Correlation with Soil Burial Degradation.

This study aimed to investigate the mechanical property decay that might occur during actual use and soil burial degradation of bamboo fiber lunch boxes. For this, the effects of three accelerated aging methods, namely damp-heat treatment, freeze-thaw cycle, and artificial weathering cycle, on the tensile strength, dynamic viscoelasticity, and chemical composition of bamboo fiber lunch boxes were compared, and a correlation of their mechanical property decay with soil burial degradation was established to obtain an acceleration factor (SAF) with aging time as a reference. The results showed that the mechanical properties of the bamboo fiber lunch box decreased to different degrees under the three accelerated methods, and the tensile strength decreased to less than 50% after 36 h of damp-heat treatment, 5 freeze-thaw cycles, and 11 artificial weathering cycles.

Formation and inhibition mechanism of novel angiotensin I converting enzyme inhibitory peptides from .

Angiotensin I converting enzyme (ACE) inhibitory peptides from fermented foods exhibit great potential to alleviate hypertension. In this study, the peptide extract from exhibited a good inhibition effect on ACE, and the inhibition rate was significantly enhanced after fermentation for 8 days. The ACE inhibitory peptides were further identified, followed by their inhibition and formation mechanisms using microbiome technology and molecular docking.

Determination of biogenic amines in Chub Mackerel from different storage methods.

The eight biogenic amines (BA), which are histamine (HIS), tryptamine, putrescine, 2-phenylethylamine, cadaverine, tyramine, spermidine, and spermine, were determined in Chub Mackerel under different storage conditions after being freshly caught. The storage time and temperature were varied and the guts either present or removed. This study describes a reverse-phase high-performance liquid chromatography (HPLC) with a fluorescence detector following precolumn derivation with dansyl chloride method for the determination of BA in in Chub Mackerel samples.

Direct thiocarbamation of imidazoheterocycles via dual C-H sulfurization.

A copper-catalyzed DTBP oxidative dual C-H sulfurization has been developed for the direct thiocarbamation of imidazopyridines using a combination of elemental sulfur and formamides as carbamothioyl surrogates. NBS (bromo succinimide) was found to promote the thiocarbamation in good yields. This dual C-H sulfurization strategy enables access to a wide range of carbamothioyl imidazoheterocycles without the use of highly toxic phosgene.

Enantioseparation and determination of triazole fungicides in vegetables and fruits by aqueous two-phase extraction coupled with online heart-cutting two-dimensional liquid chromatography.

A novel method for determination of triazole fungicides and their enantiomers in foods was developed by aqueous two-phase extraction (ATPE) coupled with two-dimensional liquid chromatography (2D-LC). With an aqueous two-phase system (ATPS) of ethanol/KHPO as biphasic extractant, the effects of the ATPS composition, extraction temperature and time on extraction yields of triazole fungicides were investigated. Optimum conditions were concluded as follows: ethanol concentration 31% (w/w) and KHPO concentration 21% (w/w), extraction temperature 60 °C, extraction time 21 min.

Sulfite-Promoted Synthesis of N-Difluoromethylthioureas via the Reaction of Azoles with Bromodifluoroacetate and Elemental Sulfur.

A sulfite-promoted transformation of azoles into N-difluoromethylthioureas through N-difluoromethylation and sulfuration has been developed. In this reaction, inexpensive ethyl bromodifluoroacetate and nontoxic elemental sulfur were used as the difluoromethylation and sulfuration reagents, respectively. A variety of azoles, including benzimidazoles, imidazoles, and triazoles, performed well to afford a broad range of azole thioureas in moderate to good yields.

Solid-phase extraction based on amino-functionalized graphene oxide nanocomposites for analysis of short-chain perfluorinated alkyl acids in human serum by ion chromatography mass spectrometry.

A highly sensitive method was developed for the analysis of short-chain perfluorinated alkyl acids (PFAAs) in serum samples using solid-phase extraction (SPE) coupled with ion chromatography-electrospray ionization-mass spectrometry. The synthesized amino-functionalized graphene oxide nanocomposites were used as an SPE sorbent for the enrichment of trace analytes and purification of samples. They exhibited high selectivity to polar compounds.

Oxidative dual C-H thiolation of imidazopyridines with ethers or alkanes using elemental sulphur.

Dual C-H thiolation reactions using elemental sulphur remain a challenge. This communication discloses an oxidative radical dual sp/sp C-H thiolation strategy for the coupling of imidazopyridines with ethers or alkanes using elemental sulphur.

Isothiocyanation of amines using the Langlois reagent.

The Langlois reagent was found to be effective for the isothiocyanation of primary amines in the presence of copper iodide and diethyl phosphonate.

Magnetic metal-organic framework MIL-100(Fe) microspheres for the magnetic solid-phase extraction of trace polycyclic aromatic hydrocarbons from water samples.

In this work, a magnetic metal-organic framework designated as MIL-100(Fe) was prepared and applied as a magnetic solid-phase extraction sorbent for the determination of trace polycyclic aromatic hydrocarbons in environmental water samples by coupling with high-performance liquid chromatography and fluorescence detection. The magnetic microspheres exhibited large surface areas and high extraction ability, making them excellent candidates as sorbents for enrichment of trace polycyclic aromatic hydrocarbons. Under the optimized experimental conditions, good sensitivity levels were achieved with low detection limits ranging from 32 to 2110 pg/mL and good linearities with correlation coefficients higher than 0.

Carboxylated graphene oxide/polyvinyl chloride as solid-phase extraction sorbent combined with ion chromatography for the determination of sulfonamides in cosmetics.

A carboxylated graphene oxide/polyvinyl chloride (CGO/PVC) material was prepared as a sorbent for the selective extraction of sulphonamides from complex sample. After being dispersed in buffer solution, sample was transferred into the prefabricated solid-phase extraction (SPE) column, which integrated extraction and cleanup into one single-step. A multi-response optimization based on the Box-Behnken design was used to optimize factors affecting extraction efficiency.

Application of microwave-assisted extraction coupled with high-speed counter-current chromatography for separation and purification of dehydrocavidine from Corydalis saxicola Bunting.

Introduction: Dehydrocavidine is a major component of Corydalis saxicola Bunting with sedative, analgesic, anticonvulsive and antibacterial activities. Conventional methods have disadvantages in extracting, separating and purifying dehydrocavidine from C. saxicola.