Category: Pyrazines

Astuti, Retno Dwi published the artcileThe Volatile Compounds and Aroma Description in Various Rhizopus oligosporus Solid-State Fermented and Nonfermented Rice Bran, Category: pyrazines, the main research area is volatile compound aroma solid state fermentation rice bran Rhizopus.

Rice bran is known to have beneficial nutrients. Current studies suggest that solid-state fermentation affects the rice bran’s volatile profile. The aim of this study is to identify the volatile compounds and aroma description of fermented and nonfermented rice bran (FRB and NFRB) of Ciherang, Inpari30, IR64 and Inpari42. The fermentation was conducted using Rhizopus oligosporus solid-state fermentation Headspace-solid phase microextraction coupled with GC/MS was performed, and the aroma was translated by 10 trained panelists through quant. descriptive anal. (QDA). The result showed that 72 and 68 compounds were identified in FRB and NFRB, resp. They are aldehydes, ketones, alcs., acids, esters, fatty acid, phenol, benzenes, furan, thiazole, pyrazines, pyridine, lactones, terpenes, and hydrocarbons. The PCA showed that FRB was dominated by alcs., whereas NFRB was dominated by aldehydes. The QDA described nine aromas, i.e., rancid, smoky, musty, grassy, green, earthy, cereal, and sweet in NFRB. The fermentation process added fermented attributes to the aroma description to FRB and enhanced the rancid, smoky, and musty aromas. These studies indicated that fermented rice bran might increase the volatile compound of rice bran. Thus, it may provide opportunities to develop the production of fermented rice bran as a functional ingredient.

Fermentation published new progress about Acids Role: BUU (Biological Use, Unclassified), BIOL (Biological Study), USES (Uses). 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Category: pyrazines.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Wu, Weihang published the artcileChanges in the physicochemical properties and volatile flavor compounds of dry-cured Chinese Laowo ham during processing, HPLC of Formula: 14667-55-1, the main research area is dry cured Chinese Laowo ham flavor physicochem property processing.

In this work, physico-chem., lipolytic, free amino acids, and volatile flavor compounds changes that occur during the processing of Laowo ham were observed Moisture content, water activity, trimethylamine- nitrogen (TMA-N), and luminosity value (L*) decreased significantly (p < .05) from 74.74%, 0.90, 22.33 mg/kg, and 51.92 to 55.66%, 0.74, 10.40 mg/kg a, nd 39.88, resp. Chloride content, pH, thiobarbituric acid (TBARS) value, peroxide value (POV), nitrite residue, and yellowness value (b*) increased significantly (p < .05) from 0.17%, 5.69, 0.06 mg/100 g, 0.03 g/100 g, 0.52 mg/kg, and 2.29 to 9.26%, 6.10, 0.33 mg/100 g,0.10 g/100 g, 1.00 mg/kg, and 5.13, resp. Eleven kinds of free fatty acids were identified. The content of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA) increased during processing. The total amount of free amino acids increased significantly (p < .05) from 4.94 mg/g to 87.89 mg/g. About 115 volatile compounds were identified.In the final products, alcs. and hydrocarbons became the dominant volatile compounds Practical applications : Laowo ham is one of the most popular dry-cured hams in southwest China's Yunnan province. At present, there are few studies on the changes in physicochem. properties and volatile flavor compounds in Laowo ham during processing, and the mechanism of flavor formation is still unknown. Therefore, the aim of the present study was to investigate the changes in physicochem. properties and flavor in Laowo ham during the production These results contribute to a more accurate understanding of the quality changes in Laowo ham during processing and help to improve the product quality and optimize the duration of processing in the future. Journal of Food Processing and Preservation published new progress about Carboxylic acids Role: BSU (Biological Study, Unclassified), BIOL (Biological Study). 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

Yuan, Tao published the artcileCeramic boron carbonitrides for unlocking organic halides with visible light, Application of 2,3,5-Trimethylpyrazine, the main research area is boron carbonitride preparation surface structure; aryl halide boron carbonitride photocatalyst hydrodehalogenation; aromatic hydrocarbon preparation; arene aryl halide boron carbonitride photocatalyst cross coupling arylation; biaryl preparation; haloarene sodium sulfinate boron carbonitride photocatalyst cross coupling sulfonylation; arylsulfone preparation.

Here, boron carbonitride (BCN) ceramics were such a system and can reduce organic halides, including (het)aryl and alkyl halides, with visible light irradn was reported. Cross-coupling of halides to afford new C-H, C-C, and C-S bonds was proceeded at ambient reaction conditions. Hydrogen, (het)aryl, and sulfonyl groups were introduced into the arenes and heteroarenes at the designed positions by means of mesolytic C-X (carbon-halogen) bond cleavage in the absence of any metal-based catalysts or ligands. BCN was used not only for half reactions, like reduction reactions with a sacrificial agent, but also redox reactions through oxidative and reductive interfacial electron transfer. The BCN photocatalyst showed tolerance to different substituents and conserved activity after five recycles. The apparent metal-free system opened new opportunities for a wide range of organic catalysts using light energy and sustainable materials, which were metal-free, inexpensive and stable.

Chemical Science published new progress about Aromatic compounds, sulfones Role: SPN (Synthetic Preparation), PREP (Preparation). 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

He, Yingxia published the artcileUnraveling the chemosensory characteristics of strong-aroma type Baijiu from different regions using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry and descriptive sensory analysis, Formula: C7H10N2, the main research area is chemosensory gas chromatog mass spectrometry; 1-Butanol (PubChem CID: 263); 2,3,5-Trimethyl-6-ethylpyrazine (PubChem CID: 28518); 2,6-Dimethylpyrazine (PubChem CID: 7938); 2-Acetylfuran (PubChem CID: 14505); Chemical and sensory profiles; Chinese strong-aroma type Baijiu; Diethyl succinate (PubChem CID: 31249); Dimethyl disulfide (PubChem CID: 12232); Furfural (PubChem CID: 7362); GC × GC-TOFMS; Methanethiol caproate (PubChem CID: 75515); Multivariate analysis; Regionality.

Comprehensive 2D gas chromatog.-time-of-flight mass spectrometry was combined with descriptive sensory anal. to elucidate the specificity of strong-aroma type Baijiu (Chinese liquor) from different regions, based on regionally distinct flavor characterized by chem. and sensory profiles. Numerous potential aroma compounds (262) were identified, among which 58 aroma compounds were significantly different between the samples from Sichuan and Jianghuai regions. Relationships between these potential aroma compounds and sensory attributes were investigated by partial least squares regression and network anal. The compounds that dominantly contributed to the important sensory attributes were identified. The high pyrazines, furanoids, and carbonyls amounts contributed to the high intensities of the cellar, toasted, and grain aroma profiles of the Sichuan region samples, while the high ester and alc. levels contributed to the fruity and floral aroma profiles of the Jianghuai region samples. This approach may have practical application in flavor characterization of other alc. beverages.

Food Chemistry published new progress about Chemoreceptors Role: BSU (Biological Study, Unclassified), BIOL (Biological Study). 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Formula: C7H10N2.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Liao, Ke published the artcileCatalytic cleavage and functionalization of bulky and inert Csp3-Csp3 bonds via a relayed proton-coupled electron transfer strategy, Safety of 2,3,5-Trimethylpyrazine, the main research area is alc radicalophile acridinium tetrafluoroborate regioselective photochem bond cleavage functionalization.

The direct, photoredox cleavage of hindered Csp3-Csp3 bonds of alcs. under neutral conditions was described. A relayed proton-coupled electron transfer (PCET) strategy was employed that overcame the previous requirement of a Bronsted base. Heavily branched alcs. with a high oxidation potential (Eox1/2 > +2 V vs. SCE) were cleaved and functionalized with remarkable efficiency and versatility. A simple, non-substituted Ph group can promote a relayed PCET process to deliver primary, secondary, and tertiary alkyl radicals under neutral conditions.

Cell Reports Physical Science published new progress about Bond cleavage catalysts (photochem., regioselective). 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

Jin, Yusuke published the artcilePyrazine Analogues on Clathrate Hydrates in Methane-Water Systems, Formula: C7H10N2, the main research area is clathrate hydrate methane water methylpyrazine system Raman spectroscopy.

This paper reports the change in equilibrium pressure-temperature (pT) boundaries in a methane (CH4)-water system by adding three pyrazine analogs: 2-methylpyrazine, 2,3-dimethylpyrazine, and 2,3,5-trimethylpyrazine. The 2-methylpyrazine, 2,3-dimethylpyrazine, and 2,3,5-trimethylpyrazine showed no effect on the clathrate hydrate structure that formed in the CH4-water system upon anal. via Raman spectroscopy. Raman spectra revealed that clathrate crystals that formed in the CH4-pyrazine analog-water system were of a structure-I CH4 hydrate. Phase equilibrium pT boundaries in the three CH4-pyrazine analog-water systems shifted to a higher p and lower T condition than that for the CH4-water system with no additive. The higher p/lower T shift confirmed that 2-methylpyrazine, 2,3-dimethylpyrazine, and 2,3,5-trimethylpyrazine act as thermodn. inhibitors for hydrate formation. The order of ΔT, a lower T shift from the CH4-water system, was as follows: 2-methylpyrazine-water > 2,3-dimethylpyrazine > 2,3,5-trimethylpyrazine. This order is in agreement with the number of -CH3 groups in the mols.

Journal of Chemical & Engineering Data published new progress about Phase equilibrium. 14667-55-1 belongs to class pyrazines, name is 2,3,5-Trimethylpyrazine, and the molecular formula is C7H10N2, Formula: C7H10N2.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Muralirajan, Krishnamoorthy published the artcileExploring the Structure and Performance of Cd-Chalcogenide Photocatalysts in Selective Trifluoromethylation, Name: 2,3,5-Trimethylpyrazine, the main research area is trifluoromethylated arene oxindole alkene preparation photochem; heteroarene alkene selective trifluoromethylation cadmium selenide catalyst.

The field of heterogeneous photoredox catalysis has grown substantially and impacted organic synthesis because of the affordability and reusability of catalysts. This study reports radical trifluoromethylation with Cd-chalcogenide semiconductors. Cd semiconductors, particularly CdSe, are readily available, com., visible-light-responsive, heterogeneous photocatalysts. The potential of readily available Cd semiconductors, particularly CdSe, is confirmed by their increased photocatalytic activity toward trifluoromethylation with various substrates, such as (hetero)arenes and vinylic amides/acids, via addition, cyclization, and decarboxylation under visible light. The economic significance of this strategy is also highlighted through the scalable synthesis of biol. active mols. followed by catalyst reuse. Moreover, these catalysts are relatively inexpensive compared with transition metal-based homogeneous photocatalysts, presently used in organic synthesis.

ACS Catalysis published new progress about Cyclization. 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

Meti, Puttavva published the artcileRegioselective synthesis of dipyrrolopyrazine (DPP) derivatives via metal free and metal catalyzed amination and investigation of their optical and thermal properties, Computed Properties of 566205-01-4, the main research area is dipyrrolopyrazine derivative preparation regioselective; dihalo pyrrolopyrazine alkyne metal catalyst amination reaction.

An efficient methods for the synthesis of dipyrrolopyrazine derivatives, I [R1 = H, C6H5; R2 = C6H5, 4-F-C6H4, (CH3)2NC6H4, cyclopropyl, etc.] and II and pyrrolothieno-pyrazine derivatives, III (X = H, C6H5) that involve regioselective amination reactions of dihalo-pyrrolopyrazines IV [Y = H, CH3, 4-CH3C6H4S(O)2; A = Br; B = Cl] is reported. The developed protocol readily affords either 2-amino- or 3-amino-pyrrolopyrazines IV (A = Br, NHCH3; B = Cl, NHCH3) from the corresponding 2-bromo-3-chloro-5H-pyrrolo[2,3-b]pyrazines IV (A = Br; B = Cl). When the amination reactions was carried under metal-free microwave irradiation, 3-amino-pyrrolopyrazines IV (A = Br; B = NHCH3) was obtained exclusively. In contrast, Buchwald cross coupling of the 2-bromo-3-chloro-5H-pyrrolo[2,3-b]pyrazines IV (A = Br; B = Cl) affords only 2-amino-pyrrolopyrazine IV (A = NHCH3; B = Cl). The pyrrolopyrazine scaffolds was converted to the resp. 1,7- I and 1,5-dihydrodipyrrolo[2,3-b]pyrazines derivatives II using Sonogashira reactions. A comprehensive study of the optical properties, thermal properties, and mol. packing of the synthesized compounds was carried out. The results indicate that the 1,7-derivatives I may be promising organic materials for optoelectronic applications.

RSC Advances published new progress about Amination. 566205-01-4 belongs to class pyrazines, name is 2-Amino-3,5-dibromo-6-chloropyrazine, and the molecular formula is C4H2Br2ClN3, Computed Properties of 566205-01-4.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Meti, Puttavva published the artcileRegioselective synthesis of dipyrrolopyrazine (DPP) derivatives via metal free and metal catalyzed amination and investigation of their optical and thermal properties, Safety of 5-Bromo-3,6-dichloropyrazin-2-amine, the main research area is dipyrrolopyrazine derivative preparation regioselective; dihalo pyrrolopyrazine alkyne metal catalyst amination reaction.

An efficient methods for the synthesis of dipyrrolopyrazine derivatives, I [R1 = H, C6H5; R2 = C6H5, 4-F-C6H4, (CH3)2NC6H4, cyclopropyl, etc.] and II and pyrrolothieno-pyrazine derivatives, III (X = H, C6H5) that involve regioselective amination reactions of dihalo-pyrrolopyrazines IV [Y = H, CH3, 4-CH3C6H4S(O)2; A = Br; B = Cl] is reported. The developed protocol readily affords either 2-amino- or 3-amino-pyrrolopyrazines IV (A = Br, NHCH3; B = Cl, NHCH3) from the corresponding 2-bromo-3-chloro-5H-pyrrolo[2,3-b]pyrazines IV (A = Br; B = Cl). When the amination reactions was carried under metal-free microwave irradiation, 3-amino-pyrrolopyrazines IV (A = Br; B = NHCH3) was obtained exclusively. In contrast, Buchwald cross coupling of the 2-bromo-3-chloro-5H-pyrrolo[2,3-b]pyrazines IV (A = Br; B = Cl) affords only 2-amino-pyrrolopyrazine IV (A = NHCH3; B = Cl). The pyrrolopyrazine scaffolds was converted to the resp. 1,7- I and 1,5-dihydrodipyrrolo[2,3-b]pyrazines derivatives II using Sonogashira reactions. A comprehensive study of the optical properties, thermal properties, and mol. packing of the synthesized compounds was carried out. The results indicate that the 1,7-derivatives I may be promising organic materials for optoelectronic applications.

RSC Advances published new progress about Amination. 960510-36-5 belongs to class pyrazines, name is 5-Bromo-3,6-dichloropyrazin-2-amine, and the molecular formula is C4H2BrCl2N3, Safety of 5-Bromo-3,6-dichloropyrazin-2-amine.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Wang, Likun published the artcileDivergent allosteric control of the IRE1α endoribonuclease using kinase inhibitors, Product Details of C9H9ClIN3, the main research area is divergent allosteric control IRE1 endoribonuclease kinase.

Under endoplasmic reticulum stress, unfolded protein accumulation leads to activation of the endoplasmic reticulum transmembrane kinase/endoRNase IRE1α. IRE1α oligomerizes, autophosphorylates and initiates splicing of XBP1 mRNA, thus triggering the unfolded protein response (UPR). Here we show that IRE1α’s kinase-controlled RNase can be regulated in two distinct modes with kinase inhibitors: one class of ligands occupies IRE1α’s kinase ATP-binding site to activate RNase-mediated XBP1 mRNA splicing even without upstream endoplasmic reticulum stress, whereas a second class can inhibit the RNase through the same ATP-binding site, even under endoplasmic reticulum stress. Thus, alternative kinase conformations stabilized by distinct classes of ATP-competitive inhibitors can cause allosteric switching of IRE1α’s RNase-either on or off. As dysregulation of the UPR has been implicated in a variety of cell degenerative and neoplastic disorders, small-mol. control over IRE1α should advance efforts to understand the UPR’s role in pathophysiol. and to develop drugs for endoplasmic reticulum stress-related diseases.

Nature Chemical Biology published new progress about Aromatic nitrogen heterocycles Role: BSU (Biological Study, Unclassified), PRP (Properties), SPN (Synthetic Preparation), BIOL (Biological Study), PREP (Preparation) (kinase inhibitors). 1320266-92-9 belongs to class pyrazines, name is 8-Chloro-1-iodo-3-isopropylimidazo[1,5-a]pyrazine, and the molecular formula is C9H9ClIN3, Product Details of C9H9ClIN3.

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem