Category: Pyrazines

Rigling, Marina published the artcileApplication of a direct immersion-stir bar sorptive extraction (DI-SBSE) combined GC-MS method for fingerprinting alkylpyrazines in tea and tea-like infusions, Name: 2,3,5-Trimethylpyrazine, the main research area is alkylpyrazine tea infusion stir bar sorptive extraction.

A series of alkylpyrazines, contributing to the overall flavor, are described in tea and tea infusions. Their low concentrations and moderate water solubility are facing anal. trouble when it comes to typical applied headspace analyses. Accordingly, a stir bar sorptive extraction methodol. (SBSE) was established. It was found that immersion-based techniques (direct-immersion SBSE (DI-SBSE) and multiple SBSE (mSBSE)) showed higher extraction efficiency compared to headspace sorptive extraction (HSSE). In the end, a DI-SBSE methodol. was established with a calibration range of 0.1-50μg/L for six alkylpyrazines to systematically quantify their presence in tea and tea-like infusions. With determined LOQs between 21 and 118 ng/L, the method was sensitive enough to detect the expected low amounts Application of the established DI-SBSE methodol. for six alkylpyrazines in seven green, three white, one oolong, two black teas, as well as two tea-like infusions (nettle and raspberry leaf) revealed great variations in total concentration of alkylpyrazines between 0.36 ± 0.05μg/L (raspberry leaf) and 24.20 ± 0.41μg/L (oolong tea). Furthermore, concentration levels in between the same tea type ranged drastically, with 14.19 ± 0.62μg/L for Longjing green tea and 0.74 ± 0.02μg/L for Warwick green tea. Most abundant alkylpyrazines in the samples were 2-methylpyrazine and 2,5-dimethylpyrazine. Overall good similarities in compositional distribution of alkylpyrazines in the same tea type and strong correlations of the alkylpyrazines over all types indicating distinct fingerprints being present and the types are differentiable based on their alkylpyrazine pattern.

European Food Research and Technology published new progress about Black tea leaves. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Name: 2,3,5-Trimethylpyrazine.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Ding, Yun published the artcileDevelopment and Synthesis of DNA-Encoded Benzimidazole Library, Formula: C5H8ClN3, the main research area is preparation DNA conjugated benzimidazole library NK3 receptor antagonist; DNA tagged fluoronitrobenzamide amine aldehyde; DNA-encoded library technology; benzimidazole.

Encoded library technol. (ELT) is an effective approach to the discovery of novel small-mol. ligands for biol. targets. A key factor for the success of the technol. is the chem. diversity of the libraries. Here we report the development of DNA-conjugated benzimidazoles. Using 4-fluoro-3-nitrobenzoic acid as a key synthon, we synthesized a 320 million-member DNA-encoded benzimidazole library using Fmoc-protected amino acids, amines and aldehydes as diversity elements. Affinity selection of the library led to the discovery of a novel, potent and specific antagonist of the NK3 receptor.

ACS Combinatorial Science published new progress about Chemical library. 39204-49-4 belongs to class pyrazines, name is Pyrazin-2-ylmethanamine hydrochloride, and the molecular formula is C5H8ClN3, Formula: C5H8ClN3.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Demirgul, Furkan published the artcileProduction and characterization of yeast extracts produced by Saccharomyces cerevisiae, Saccharomyces boulardii and Kluyveromyces marxianus, Quality Control of 14667-55-1, the main research area is Saccharomyces cerevisiae boulardii Kluyveromyces marxianus yeast extract characterization; Amino acids; Kluyveromyces marxianus; Saccharomyces boulardii; Saccharomyces cerevisiae; volatile compounds; yeast extract.

In recent years, prejudice in society against monosodium glutamate (MSG) has directed food manufacturers to alternative sources. Yeast extracts are considered as “”natural”” due to the production process and stand out due to their nutritional properties as well as giving a flavor similar to MSG. In this study, chem., functional and flavor properties of yeast extract powders produced from Saccharomyces cerevisiae TGM10, Saccharomyces boulardii S11 and Kluyveromyces marxianus TGM66 were evaluated. Results revealed that the most protein-rich sample was S. cerevisiae TGM10 extract (69.17%), followed by S. boulardii S11 (66.16%) and K. marxianus TGM66 (62.42%) extracts, resp. and S. cerevisiae TGM10 extract was also the richest yeast extract for essential amino acids. Addnl., flavor-enhancing amino acids such as glutamic acid, aspartic acid, alanine and glycine were dominant in S. cerevisiae TGM10 extract (47.41 g/100 g protein). Sensorial evaluation of yeast extracts demonstrated that salty taste, umami taste and meaty flavor scores of yeast extracts were lower than MSG whereas for fruity flavor, yeast extracts had the highest scores. These findings revealed the potential of three yeast strains to produce yeast extracts in order to increase the nutritional value and flavor of foods.

Preparative Biochemistry & Biotechnology published new progress about Cluster analysis. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Quality Control of 14667-55-1.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Song, Xuebo published the artcileCharacterization of key aroma-active sulfur-containing compounds in Chinese Laobaigan Baijiu by gas chromatography-olfactometry and comprehensive two-dimensional gas chromatography coupled with sulfur chemiluminescence detection, HPLC of Formula: 14667-55-1, the main research area is Baijiu aroma gas chromatog olfactometry; 2-Furfurylthiol; 2-Furfurylthiol, (PubChem CID: 7363); 2-Methyl-3-furanthiol; 2-Methyl-3-furanthiol, (PubChem CID: 34286); AEDA; Baijiu; Benzenemethanethiol; Benzenemethanethiol, (PubChem CID: 7509); Dimethyl disulfide, (PubChem CID: 12232); Dimethyl trisulfide, (PubChem CID: 19310); GC × GC; Methional, (PubChem CID: 18635); Sulfur chemiluminescence detection.

Volatile sulfur-containing compounds (VSCs) often exist at extremely low concentrations, making them difficult to be determined The VSCs in Laobaigan (LBG) Baijiu were analyzed by headspace solid-phase microextraction (HS-SPME) coupled with GC × GC-SCD, by which 12 VSCs were identified. Among the 65 odor-active compounds that were determined by GC-O with the aid of aroma extract dilution anal. (AEDA), benzenemethanethiol and 2-methyl-3-furanthiol were found to possess the highest FD values of 6561. The limits of detection (LODs) of the identified VSCs determined by GC × GC-SCD were found to be extremely low at 0.05-1.53 ng/L, with their anal. recoveries from 85% to 116%. The VSCs in the LBG samples were determined in a range of concentrations from 0.77 ± 0.02 μg/L to 60.04 ± 2.32 μg/L. Benzenemethanethiol, di-Me trisulfide, 2-methyl-3-furanthiol and 2-furfurylthiol exhibited odor activity values (OAVs) > 100 and significantly contributed to the overall aroma of LBG Baijiu.

Food Chemistry published new progress about Alcoholic beverages. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, HPLC of Formula: 14667-55-1.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Nagnan-Le Meillour, Patricia published the artcileIdentification of potential chemosignals in the European water vole Arvicola terrestris, Safety of 2,3,5-Trimethylpyrazine, the main research area is lipocalin santene cresol coumarin chemosignal.

The water vole Arvicola terrestris is endemic to Europe where its outbreak generates severe economic losses for farmers. Our project aimed at characterizing putative chem. signals used by this species, to develop new sustainable methods for population control that could also be used for this species protection in Great Britain. The water vole, as well as other rodents, uses specific urination sites as territorial and sex pheromone markers, still unidentified. Lateral scent glands and urine samples were collected from wild males and females caught in the field, at different periods of the year. Their volatile composition was analyzed for each individual and not on pooled samples, revealing a specific profile of flank glands in Oct. and a specific profile of urinary volatiles in July. The urinary protein content appeared more contrasted as males secrete higher levels of a lipocalin than females, whenever the trapping period. We named this protein arvicolin. Male and female liver transcript sequencing did not identify any expression of other odorant-binding protein sequence. This work demonstrates that even in absence of genome, identification of chem. signals from wild animals is possible and could be helpful in strategies of species control and protection.

Scientific Reports published new progress about Arvicola terrestris. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Safety of 2,3,5-Trimethylpyrazine.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Yang, Ji-Su published the artcileVolatile metabolic markers for monitoring Pectobacterium carotovorum subsp. carotovorum Using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry, Product Details of C7H10N2, the main research area is Pectobacterium carotovorum volatile metabolic marker HS SPME GC MS; Cabbage; Pectobacterium; soft rot; solid-phase microextraction; volatile metabolic marker.

Identifying the extracellular metabolites of microorganisms in fresh vegetables is industrially useful for assessing the quality of processed foods. Pectobacterium carotovorum subsp. carotovorum (PCC) is a plant pathogenic bacterium that causes soft rot disease in cabbages. This microbial species in plant tissues can emit specific volatile mols. with odors that are characteristic of the host cell tissues and PCC species. In this study, we used headspace solid-phase microextraction followed by gas chromatog. coupled with mass spectrometry (HS-SPME-GC-MS) to identify volatile compounds (VCs) in PCC-inoculated cabbage at different storage temperatures HS-SPME-GC-MS allowed for recognition of extracellular metabolites in PCC-infected cabbages by identifying specific volatile metabolic markers. We identified 4-ethyl-5-methylthiazole and 3-butenyl isothiocyanate as markers of fresh cabbages, whereas 2,3-butanediol and Et acetate were identified as markers of soft rot in PCC-infected cabbages. These anal. results demonstrate a suitable approach for establishing non-destructive plant pathogen-diagnosis techniques as alternatives to standard methods, within the framework of developing rapid and efficient anal. techniques for monitoring plant-borne bacterial pathogens. Moreover, our techniques could have promising applications in managing the freshness and quality control of cabbages.

Journal of Microbiology and Biotechnology published new progress about Bacterial infection. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Product Details of C7H10N2.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Lin, Daniel published the artcileVisible Light-Mediated Metal-Free Chlorodifluoromethylation of Arenes and Heteroarenes by a Hypervalent Iodine EDA Complex, Synthetic Route of 14667-55-1, the main research area is arene heteroarene chlorodifluoromethylation visible light hypervalent iodine EDA complex.

A novel EDA complex comprised of a bis(chlorodifluoroacetoxy)iodoarene and 1,3,5-trimethoxybenzene is described, which enables the direct radical C(sp2)-H chlorodifluoromethylation of arenes and heteroarenes under monochromatic visible-light irradiation The procedure is mild, operationally simple, and utilizes com. available reagents. The developed conditions demonstrate compatibility with a host of commonly encountered functionalities and biol. relevant scaffolds, while showcasing the post-functionalization capabilities of the -CF2Cl moiety. Various mechanistic studies were performed to explore the EDA complex and radical generation pathway.

European Journal of Organic Chemistry published new progress about C-H bond activation. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Synthetic Route of 14667-55-1.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Verevkin, Sergey P. published the artcileEnergetics of LOHC: Structure-Property Relationships from Network of Thermochemical Experiments and in Silico Methods, Application of 2,3,5-Trimethylpyrazine, the main research area is liquid organic hydrogen carrier structure property relationship.

The storage of hydrogen is the key technol. for a sustainable future. We developed an in silico procedure, which is based on the combination of exptl. and quantum-chem. methods. This method was used to evaluate energetic parameters for hydrogenation/dehydrogenation reactions of various pyrazine derivatives as a seminal liquid organic hydrogen carriers (LOHC), that are involved in the hydrogen storage technologies. With this in silico tool, the tempo of the reliable search for suitable LOHC candidates will accelerate dramatically, leading to the design and development of efficient materials for various niche applications.

Hydrogen published new progress about Combustion enthalpy. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Application of 2,3,5-Trimethylpyrazine.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Lumma, William C. Jr. published the artcilePiperazinylimidazo[1,2-a]pyrazines with selective affinity for in vitro α-adrenergic receptor subtypes, Name: 8-Bromoimidazo[1,2-a]pyrazine, the main research area is piperazinylimidazopyrazine preparation alpha adrenergic agonist; potential energy piperazinylimidazopyrazine; conformation piperazinylimidazopyrazine; NMR piperazinylimidazopyrazine; structure activity piperazinylimidazopyrazine.

The title compounds I (R = H, etc.; R1 = H, Cl, Me, etc.; R2 = H, piperazinyl, etc.; R3 = H, Cl, Ph, piperazinyl; R4 = H, piperazino or methylpiperazino) were prepared and evaluated in vitro for their affinity for α1- and α2-adrenergic receptors. 8-(1-piperazinyl)imidazo[1,2-a]pyrazine (II) [76537-53-6] was ∼70 times more selective than mianserin for the α2-receptor. Computer-assisted mol. modeling techniques were used to describe possible preferred conformations for receptor binding. Regioselective syntheses of the heterocyclic ring system are given. Literature NMR assignments for the imidazo[1,2-a]pyrazine ring system were made. Conformational energies for II and its 5-position isomer in relation to the semirigid mianserin were estimated Structure-activity relations are discussed.

Journal of Medicinal Chemistry published new progress about Molecular mechanics. 69214-34-2 belongs to class pyrazines, name is 8-Bromoimidazo[1,2-a]pyrazine, and the molecular formula is C6H4BrN3, Name: 8-Bromoimidazo[1,2-a]pyrazine.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Cho, Kye Man published the artcileComparative assessment of compositional constituents and antioxidant effects in ginseng sprouts (Panax ginseng) through aging and fermentation processes, Recommanded Product: 2,3,5-Trimethylpyrazine, the main research area is Panax composition antioxidant aging fermentation process.

The main objectives of this research was to demonstrate fluctuations of compositional constituents and antioxidant effects in aging (AGS) and fermentation (FAGS) processes regarding beneficial qualities of food industry from dried ginseng sprouts (DGS). Moreover, our wok is the first to compare the influential factors on antioxidant and physicochem. properties. Total amino acids (4537 → 2129 → 2450 mg/100g) and volatiles (3538 → 1015 → 325 ng/g) decreased considerably during DGS → AGS → FAGS processes, specifically, arginine (2490 → 1034 → 1351 mg/100g) and β-farnesene (1940 → 202 → 19 ng/g) showed the predominant decrease rates. Total ginsenoside contents also decreased with 37.39 → 33.83 → 34.52 mg/g, however, the deglycosilated ginsenoside F2 (2.15 → 3.56 → 4.59 mg/g, 2.1-fold) and compound K (CK) (0.75 → 2.98 → 4.07 mg/g, 5.4-fold) increased with high variations. Interestingly, ginsenoside Re decreased with the highest variation rate (6.47 → 2.45 → 1.53 mg/g, 4.2-fold). The antioxidant capacities increased remarkably with approx. 2 times in DGS → AGS → FAGS steps as follows: ABTS assay > DPPH assay > hydroxyl radical scavenge > FRAP at 1000 μg/mL. In particular, processed ginseng sprouts were observed high values of total phenolic content (TPC) (2.4 → 4.9 → 5.5 GAE/g), total flavonoid content (TFC) (0.5 → 0.9 → 1.3 RE/g), and of maillard reaction products (MRP) (2.0 → 2.8 → 2.9 OD420nm) than DGS. Our results suggest that AGS and FAGS may be utilized as potential candidates on beneficial compositions and natural antioxidants for functional foods.

LWT–Food Science and Technology published new progress about Aging of materials. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Recommanded Product: 2,3,5-Trimethylpyrazine.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem