4-methylimidazole

The reactions of [W(CBr)(CO)2 (Tp*)] (Tp* = tris(dimethylpyrazolyl)borate) with LiTeCCR (R = SiMe3 , Sii Pr3 , i Pr, n Bu, t Bu, Ph, C6 H4 Me-4, methylimidazol-2-yl) afford the first alkynyltellurolatocarbynes [W(CTeCCR)(CO)2 (Tp*)]. Both the WC and CC multiple bonds are prone to metal addition as exemplified by treatment with [MCl(SMe2 )] (M = Cu, Au) to afford the hexametallic complex [W2 Cu4 (μ-CTeCCSii Pr3 )2 Cl4 (CO)4 (Tp*)2 ] and [WAu(μ-CTeCCSiMe3 )Cl(CO)2 -(Tp*)] which evolves to the unusual hypervalent [WAu(μ-CTeCl4 )(SMe2 )(CO)2 (Tp*)]...

In this study, polymeric ionic liquids featuring different functional moieties were applied as sorbent coatings in direct-immersion solid-phase microextraction (DI-SPME) for the extraction of 2-methylimidazole (2-MI) and 4-methylimidazole (4-MI) from açaí-based food products followed by gas chromatography-mass spectrometry (GC-MS) analysis. The analytical method was optimized using a sequential experimental design. Variables used in GC-MS such as desorption time, as well as for SPME-DI, including extraction time, extraction temperature, incubation time of extraction, amount of NaCl in the extract, and stirring rate, were optimized...

4-Methylimidazole (4-MEI), as a Maillard reaction product, often occurs in heat-processed food. Due to its widespread occurrence and strong carcinogenicity in food and beverages, 4-MEI has received attention from regulatory organizations and consumers. Some studies have reported the occurrence and exposure of 4-MEI in food, but few studies have involved traditional tea beverages, which is related to the limited analytical methods currently being influenced by complex tea matrices. For this issue, this study presents a simple, reliable, and highly sensitive analytical method for the determination of 4-MEI in tea using liquid chromatography-high resolution mass spectrometry...

Poly(N-isopropylacrylamide) thermosensitive hydrogel tube tip solid-phase extraction/ultra-high liquid chromatography-mass spectrometry (UPLC-MS/MS) method was developed for analysis of methylimidazoles in beverages. Thermosensitive poly(N-isopropylacrylamide) (PNIPA) hydrogel solid-phase extraction (SPE) medium was prepared on the surface of highly internal phase emulsion (HIPE) porous polymer by thermally initiated polymerization in a tube tip. The temperature sensitive SPE medium has the characteristics of high porosity and high specific surface area...

A qualitative and quantitative method for detecting free and protein-bound advanced glycation end products (AGEs) and 4-methylimidazole (4-MI) was established using isotope dilution-HPLC-MS/MS, and successfully applied in cookies and model systems. The effects of different temperatures (160-220 °C) on the formation of free and protein-bound AGEs and 4-MI in cookies were discussed, and the possible model systems (Maillard reaction pathway 1 using wheat gluten protein + glucose + sucrose; direct addition pathway 1 using wheat gluten protein + CML/CEL/4-MI) of protein-bound AGEs and 4-MI were verified...

The inhibitory effects of liquiritigenin, liquiritin and glycyrrhizic acid against the hazards during the preparation of thermal reaction beef flavoring were investigated using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Liquiritigenin(1.5 mM) inhibited Nε -carboxymethyl-L-lysine and Nε -carboxyethyl-L-lysine by up to 38.69 % and 61.27 %, respectively; 1.5 mM liquiritin inhibited 4-methylimidazole by up to 48.28 %; and 1.5 mM liquiritigenin and 1...

Compromised maternal health leading to maternal seizures can have adverse effects on the healthy development of offspring. This may be the result of inflammation, hypoxia-ischemia, and altered GABA signaling. The current study examined cortical tissue from F2b (2nd litter of the 2nd generation) postnatal day 4 (PND4) offspring of female Harlan SD rats chronically exposed to the seizuregenic compound, 4-Methylimidazole (0, 750, or 2500 ppm 4-MeI). Maternal seizures were evident only at 2500 ppm 4-MeI...

4-methylimidazole (4-MEI) is widely used industrially. This carcinogenic component has been reported in some types of food. It is usually produced by the caramelization process in food, drinks and caramel coloring. The possible mechanism for the formation of this compound in food is the Maillard reaction. In order to estimate the amount of substance 4-MEI in food, a systematic study was conducted. The selected keywords were 4-methylimidazole, 4-MEI, beverage, drink, meat, milk, and coffee. 144 articles were obtained from the initial search...

Spring viraemia of carp virus (SVCV), a highly pathogenic rhabdovirus, could cause spring viraemia of carp (SVC) with up to 90% lethality. Like other rhabdoviruses, the entry of SVCV into susceptible cells was mediated by a single envelope glycoprotein G. Specific inhibitors targeting the glycoprotein were the most effective means to alleviate the epidemic. The programs including SWISS-MODEL, I-TASSER, Phyre2 and AlphaFold2 were used to build a three-dimensional structural model of glycoprotein. The structural comparison between SVCV-G and homology protein VSV-G revealed that the SVCV glycoprotein ectodomain (residues 19 to 466) folded into four distinct domains...

Roasting is responsible for imparting the main characteristics to coffee, but the high temperatures used in the process can lead to the formation of several potentially toxic substances. Among them, polycyclic aromatic hydrocarbons, acrylamide, furan and its derivative compounds, α-dicarbonyls and advanced glycation end products, 4-methylimidazole, and chloropropanols stand out. The objective of this review is to present a current and comprehensive overview of the chemical contaminants formed during coffee roasting, including a discussion of mitigation strategies reported in the literature to decrease the concentration of these toxicants...

The increasing resistance of Toxoplasma gondii to drugs and side effects of therapy indicate that specific treatment for these parasites is still needed. The 4-arylthiosemicarbazide derivatives seem to be a solution to this challenge because they have low cytotoxicity against host cells and high anti-T. gondii activity. The molecular mechanism for these compounds is related to the inhibition of tyrosine amino acids involved in the proliferation and parasitophorous vacuole formation. The pharmacokinetic analysis shows that 1-(4-Methylimidazol-5-oyl)-4-(4-nitrophenyl)thiosemicarbazide and 4-(3-Iodophenyl)-1-(4-methylimidazol-5-oyl)thiosemicarbazide administered intragastrically pass into the bloodstream and cross the blood-brain barrier, and the absorption of both compounds is first-order absorption...

Cross-linked epoxy resin (EP) single-hole Janus hollow spheres are prepared by cross-linking induced phase separation within an emulsion droplet and selective modification. The droplet is composed of an EP oligomer, toluene, and hexadecane. 2-Ethyl-4-methylimidazole is used as the cross-linker added to the aqueous phase. During the cross-linking, hexadecane forms an eccentric core in the cross-linked EP sphere. A single hole forms across the shell after dissolving the solvents, and a single-hole hollow sphere is achieved...

Hemoglobins M (Hbs M) are human hemoglobin variants in which either α or β subunit contains a ferric heme in the α2 β2 tetramer. Though the ferric subunit cannot bind O2 , it regulates O2 affinity of its counterpart ferrous subunit. We have investigated resonance Raman spectra of two Hbs M Iwate (α87His → Tyr) and M Boston (α58His → Tyr), having tyrosine as a heme axial ligand at proximal and distal positions, respectively, that exhibit unassigned resonance Raman bands arising from ferric (not ferrous) hemes at 899 and 876 cm-1 ...

BACKGROUND: 4-Methylimidazole (4-MeI) or 4-methyl-1H-imidazole, a slightly yellowish solid with molecular formula C4 H6 N2 , is a heterocyclic compound which supposedly does not exist as a natural product and is formed when carbohydrates are heating with ammonium compounds. This compound is used in pharmaceuticals, agriculture and photography chemicals, dyes and pigments, and rubber manufacturing. In the present study, a simple and efficient sample preparation method designated gas flow headspace liquid phase microextraction (GF-HS-SDME) was employed for the extraction and preconcentration of 4-methylimidazole (4-MeI) from food and beverage samples, before its determination by gas chromatography-mass spectrometry...

Individuals of all ages, including children and teenagers, consume 4-methylimidazole (4-MI) in their food. 4-MI is a caramel-colored waste product that has previously been linked to human carcinogenesis and has shown possible signs of reproductive toxicity. This study aimed to determine whether 4-MI is harmful to oocytes during meiosis and fertilization. Female mice were intragastrically administered 0, 50, or 100 mg/kg body weight of 4-MI daily for 10 days. We found that 4-MI affects the quality of oocytes by affecting their meiotic ability and fertility potential...

Recently, deep eutectic solvents (DESs), a new type of solvent, have been studied widely for CO2 capture. In this work, the anion-functionalized deep eutectic solvents composed of phenol-based ionic liquids (ILs) and hydrogen bond donors (HBDs) ethylene glycol (EG) or 4-methylimidazole (4CH3 -Im) were synthesized for CO2 capture. The phenol-based ILs used in this study were prepared from bio-derived phenols carvacrol (Car) and thymol (Thy). The CO2 absorption capacities of the DESs were determined. The absorption mechanisms by the DESs were also studied using nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and mass spectroscopy...

Herein, a facile and fast surface-enhanced Raman scattering (SERS) method with ratiometric strategy was developed for detection of 4-methylimidazole (4-MI). Via a chemical derivatization reaction with 3-amino-5-mercapto-1,2,4-triazole (AMTA) diazonium salts, 4-MI could be converted to SERS-sensitive species. The SERS intensity ratio between the peaks at 1243 cm-1 and 1110 cm-1 (I1243 /I1110 ) was used for the quantification of 4-MI. In addition, the method sensitivity was further improved by the aggregation of beta-cyclodextrin-modified Ag nanoparticles (beta-CD-AgNPs)...

The National Toxicology Program (NTP) reported that chronic exposure to varying dietary concentrations of 4-methylimidazole (4-MeI) increased lung tumors in female and male mice [1]. In this study, mice (male and female B6C3F1 mice) were either administered 4-MeI by oral gavage (0, 50, 100, 200, or 300 mg/kg/day) for 2 days or exposed for 5 and 28 days to 4-MeI in the diet (0, 150, 300, 1250, or 2500 ppm) and whole transcriptome (RNA-Sequencing) data from 4-MeI-exposed B6C3F1 mice to determine whether changes occurred in the target (lung) and nontarget (liver) tissues...

The National Toxicology Program (NTP) reported that chronic dietary exposure to 4-methylimidazole (4-MeI) increased the incidence of lung adenomas/carcinomas beyond the normally high spontaneous rate in B6C3F1 mice. To examine plausible modes of action (MoAs) for mouse lung tumors (MLTs) upon exposure to high levels of 4-MeI, and their relevance in assessing human risk, a systematic approach was used to identify and evaluate mechanistic data (in vitro and in vivo) in the primary and secondary literature, along with high-throughput screening assay data...

Signal Amplification By Reversible Exchange (SABRE) is a popular method for generating strong signal enhancements in Nuclear Magnetic Resonance (NMR). In SABRE experiments, the source of polarization is provided by the non-thermal spin order of parahydrogen (pH2 , the H2 molecule in its nuclear singlet spin state). Polarization formation requires that both pH2 and a substrate molecule bind to an Ir-based complex where polarization transfer occurs. Subsequently, the complex dissociates and free polarized substrate molecules are formed...