Day: April 15, 2022

Category: chiral-catalyst. Aromatic compounds can be divided into two categories: single heterocycles and fused heterocycles. Compound: 2-Ethylpyrazine, is researched, Molecular C6H8N2, CAS is 13925-00-3, about Quantitation of pyrazines in roasted green tea by infrared-assisted extraction coupled to headspace solid-phase microextraction in combination with GC-QqQ-MS/MS. Author is Yang, Yanqin; Zhang, Mingming; Hua, Jinjie; Deng, Yuliang; Jiang, Yongwen; Li, Jia; Wang, Jinjin; Yuan, Haibo; Dong, Chunwang.

Pyrazines play an important role in the characteristic flavor of roasted green tea due to powerful strong odours and low sensory thresholds. It is important to analyze these compounds reliably and rapidly in roasted green tea. In this study, IR-assisted extraction coupled to headspace solid-phase microextraction (IRAE-HS-SPME) and gas chromatog.-triple quadrupole-tandem mass spectrometry (GC-QqQ-MS/MS) were developed and validated to determine the pyrazines in roasted green tea. Good linear correlation coefficients (0.9955-0.9996) were obtained over the concentration ranges of 10-5000 ng/mL. The limits of detection (LODs) and limits of quantification (LOQs) for the pyrazines were in the range of 1.46-3.27 ng/mL and 4.89-10.90 ng/mL, resp. The average recoveries varied from 84% to 119%. The method was used to analyze the pyrazines in roasted green tea manufactured by different final firing methods, the results revealed that microwave final firing method had maximum contents of pyrazines, and significantly improved the aroma quality. In addition, there were great disparities of pyrazines in flatten-shaped green tea and strip-shaped green tea according to the appearance. The result is expected to better understand the role of pyrazines related to aroma quality of roasted green tea and improve processing technol.

Although many compounds look similar to this compound(13925-00-3)Category: chiral-catalyst, numerous studies have shown that this compound(SMILES:CCC1=NC=CN=C1), has unique advantages. If you want to know more about similar compounds, you can read my other articles.

Reference:
Chiral Catalysts,
Chiral catalysts – SlideShare

In organic chemistry, atoms other than carbon and hydrogen are generally referred to as heteroatoms. The most common heteroatoms are nitrogen, oxygen and sulfur. Now I present to you an article called Synthesis and Study of Some New Histidine Derivatives, published in 2014-04-30, which mentions a compound: 542-58-5, mainly applied to Schiff base imidazole oxazole preparation, Synthetic Route of C4H7ClO2.

The oxazole I was prepared by reaction of histidine with acetic anhydride, which on treatment with thiosemicarbazide afforded ((4-(1H-imidazol-4-ylmethyl)-2-methyl-4,5-dihydro-1,3-oxazol-5-ylidene)amino)thiourea (Schiff base) . The desired histidine derivatives, e.g., II, were synthesized from Schiff base and oxazole I via various organic reactions.

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Reference:
Chiral Catalysts,
Chiral catalysts – SlideShare

The three-dimensional configuration of the ester heterocycle is basically the same as that of the carbocycle. Compound: 2-Chloroethyl acetate(SMILESS: CC(OCCCl)=O,cas:542-58-5) is researched.Quality Control of 2-Chloroethyl acetate. The article 《Synthesis of novel indanone derivatives having biological activities》 in relation to this compound, is published in Tap Chi Hoa Hoc. Let’s take a look at the latest research on this compound (cas:542-58-5).

From the 3-acetylaminoindan-1-one obtained during the course of their work, the authors performed the synthesis of novel indanone derivatives as new antitumor agents (no data), by acidic hydrolysis of the acetamide group, diazotization and alkylation of the amino group and bromination of the cyclopentane methylene group.

Although many compounds look similar to this compound(542-58-5)Quality Control of 2-Chloroethyl acetate, numerous studies have shown that this compound(SMILES:CC(OCCCl)=O), has unique advantages. If you want to know more about similar compounds, you can read my other articles.

Reference:
Chiral Catalysts,
Chiral catalysts – SlideShare

The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Action of aluminum chloride on esters of polyatomic alcohols》. Authors are Sivertsev, A. P..The article about the compound:2-Chloroethyl acetatecas:542-58-5,SMILESS:CC(OCCCl)=O).Quality Control of 2-Chloroethyl acetate. Through the article, more information about this compound (cas:542-58-5) is conveyed.

Summary of a thesis. Heating an equimolar mixture of AlCl3 and (AcOCH2)2 1 h. to 150-60° gave ClCH2CH2OAc, b. 142-8°, and ClAl(OAc)2, a glassy mass (after washing with benzene and Et2O). Similar treatment of (BzOCH2)2 gave ClCH2CH2OBz, b17 139-40°, 20201783, nD20 1.5233, and ClAl(OBz)2. Similar reaction of an equimolar mixture of AlCl3 with triacetin gave ClCH2CH(OAc)CH2OAc, b20 125-30°, d2020 1.2018, nD20 1.4393; the use of 0.5 mol triacetin gave ClCH2CHClCH2OAc, b20 90-5°, d2020 1.2733, nD20 (not given); the AlCl3 was found to have been transformed into ClAl(OAc)2. Further heating of the dichloropropyl acetate with AlCl3 failed to produce further reaction. Pentaerythritol tetra-acetate (1 mol) heated as above with 0.5 mol AlCl3 gave ClCH2C(CH2OAc)3, b4.5 152-60°, d2020 1.2272, nD20 1.4587; an equimolar mixture gave (ClCH2)2C(CH2OAc)2, b6 146-8°, d2020 1.268, nD20 1.4681; 0.5 mol of the ester to 1 mol AlCl3 gave (ClCH2)3CCH2OAc, b8 126-7°, d2020 1.3111, nD20 1.4832. The Al is transformed into ClAl(OAc)2. Hydrolysis of the chlorides, followed by acetylation, gave the original tetraacetate, showing that no changes of the skeleton took place. Thus, AlCl3 is incapable of replacing all OAc groups by Cl in polyacetate esters of polyat. alcs.; 1 ester group always remains intact.

Although many compounds look similar to this compound(542-58-5)Quality Control of 2-Chloroethyl acetate, numerous studies have shown that this compound(SMILES:CC(OCCCl)=O), has unique advantages. If you want to know more about similar compounds, you can read my other articles.

Reference:
Chiral Catalysts,
Chiral catalysts – SlideShare

In general, if the atoms that make up the ring contain heteroatoms, such rings become heterocycles, and organic compounds containing heterocycles are called heterocyclic compounds. An article called Exploring the volatile metabolome of conventional and organic walnut oils by solid-phase microextraction and analysis by GC-MS combined with chemometrics, published in 2021-11-30, which mentions a compound: 13925-00-3, Name is 2-Ethylpyrazine, Molecular C6H8N2, Related Products of 13925-00-3.

It is challenging to establish a correlation between the agronomical practices and the volatile profile of high-value agricultural products. In this study, the volatile metabolome of walnut oils from conventional and organic farming type was explored by HS-SPME-GC-MS. The SPME protocol was optimized after evaluating the effects of extraction time, extraction temperature, and sample mass. The optimum parameters involved the extraction of 0.500 g walnut oil at 40°C within 60 min. Twenty Greek walnut oils produced with conventional and organic farming were analyzed and 41 volatile compounds were identified. The determined compounds were semi-quantified, and further processed with chemometrics. Agglomerative hierarchical clustering (AHC) and principal component anal. (PCA) were used. A robust classification model was developed using sparse partial least squares-discriminant anal. (sPLS-DA) for the discrimination of walnut oils into conventional and organic, establishing volatile markers that could be used to guarantee the type of farming.

Although many compounds look similar to this compound(13925-00-3)Related Products of 13925-00-3, numerous studies have shown that this compound(SMILES:CCC1=NC=CN=C1), has unique advantages. If you want to know more about similar compounds, you can read my other articles.

Reference:
Chiral Catalysts,
Chiral catalysts – SlideShare

Related Products of 13925-00-3. Aromatic heterocyclic compounds can also be classified according to the number of heteroatoms contained in the heterocycle: single heteroatom, two heteroatoms, three heteroatoms and four heteroatoms. Compound: 2-Ethylpyrazine, is researched, Molecular C6H8N2, CAS is 13925-00-3, about Effect of baking on the flavor stability of green tea beverages. Author is Fu, Yan-Qing; Wang, Jie-Qiong; Chen, Jian-Xin; Wang, Fang; Yin, Jun-Feng; Zeng, Liang; Shi, John; Xu, Yong-Quan.

Flavor stability is important for the quality of tea beverages. Baking is a typical processing technol. to improve the flavor of tea leaves. In present study, seven raw tea materials, including steamed spring and autumn tea leaves, pan-fired spring tea leaves, and their corresponding baked tea leaves, were used to investigate the effect of baking on flavor stability of green tea beverages. The results showed that tea beverages prepared with baked tea had better flavor stability. The baking process obviously changed the concentrations of some important flavor substances, especially the aromatic pyrrole substances from 0 (unbaked) to 338.13μg/L (baked) in tea beverages. Heat treatment had little influence on the flavor of tea beverages prepared from baked tea, but caused great changes in non-volatile and volatile components in those prepared from unbaked leaves. These results could help guide the processing of tea beverages which would improve their flavor quality stability.

Although many compounds look similar to this compound(13925-00-3)Related Products of 13925-00-3, numerous studies have shown that this compound(SMILES:CCC1=NC=CN=C1), has unique advantages. If you want to know more about similar compounds, you can read my other articles.

Reference:
Chiral Catalysts,
Chiral catalysts – SlideShare

Ongo, Emelda A.; Montevecchi, Giuseppe; Antonelli, Andrea; Sberveglieri, Veronica; Sevilla, Fortunato III published an article about the compound: 2-Ethylpyrazine( cas:13925-00-3,SMILESS:CCC1=NC=CN=C1 ).Computed Properties of C6H8N2. Aromatic heterocyclic compounds can be classified according to the number of heteroatoms or the size of the ring. The authors also want to convey more information about this compound (cas:13925-00-3) through the article.

Volatile metabolites of Philippine Arabica and Robusta coffee beans in both forms standard (not-eaten by the Asian palm civet) and civet coffee grown in different Philippine regions were identified using the hyphenated technique headspace-solid phase microextraction-gas chromatog.-mass spectrometry. A great number of volatile metabolites with a wide variety of functional groups were extracted and forty-seven prominent compounds were identified. The volatile metabolomics (volatilomics) fingerprint of Arabica coffees considerably differed from Robusta coffee and geog. origin slightly altered the fingerprint profile of coffee samples. Chemometric anal. such as principal component anal. (PCA) displayed a good classification between Arabica and Robusta coffee samples. Although Arabica coffee samples from different geog. origins were clustered sep. from each other, the proximity of clusters between Arabica coffee samples which could be classified into one large group, indicated their close similarity of headspace metabolites. The distinction between Arabica samples and Robusta coffees was attributed through the PCA to several key volatile metabolites, in particular, higher quantities of acetic acid, furfural, 5-methylfurfural, 2-formylpyrrole and maltol and lower concentrations of 4-ethylguaiacol and phenol. These discriminating metabolites could represent useful quality markers to differentiate Arabica from Robusta coffee. Results revealed that the headspace metabolites in coffee provide significant information on its inherent aroma quality. Also, the findings suggested that the overall quality of Philippine coffee is variety and region-specific.

Although many compounds look similar to this compound(13925-00-3)Computed Properties of C6H8N2, numerous studies have shown that this compound(SMILES:CCC1=NC=CN=C1), has unique advantages. If you want to know more about similar compounds, you can read my other articles.

Reference:
Chiral Catalysts,
Chiral catalysts – SlideShare

Most of the natural products isolated at present are heterocyclic compounds, so heterocyclic compounds occupy an important position in the research of organic chemistry. A compound: 10466-61-2, is researched, SMILESS is N[C@@H](CC(C)C)C(N)=O.[H]Cl, Molecular C6H15ClN2OJournal, Biotechnology Techniques called Mass transfer induced interchange of the kinetic and thermodynamic control of enzymic peptide synthesis in biphasic water-organic systems, Author is Nadim, A.; Stoineva, I. B.; Galunsky, B.; Kasche, V.; Petkov, D. D., the main research direction is enzymic peptide coupling kinetics thermodn; chymotrypsin peptide coupling kinetics thermodn.Category: chiral-catalyst.

Peptide synthesis catalyzed by α-chymotrypsin in water and in biphasic water-Me iso-Bu ketone systems is compared. An interchange of the reaction control was observed in the biphasic system at high enzyme concentration due to substrate and product partitioning. Under these conditions, the rate of mass transfer between the phases was the rate-limiting step, and the hydrolysis product concentration had a transient maximum ≫ equilibrium value. In this case, most of the peptide was prepared in a thermodynamically controlled process. In the aqueous one-phase system, the peptide synthesis was kinetically controlled.

Although many compounds look similar to this compound(10466-61-2)Category: chiral-catalyst, numerous studies have shown that this compound(SMILES:N[C@@H](CC(C)C)C(N)=O.[H]Cl), has unique advantages. If you want to know more about similar compounds, you can read my other articles.

Reference:
Chiral Catalysts,
Chiral catalysts – SlideShare

Epoxy compounds usually have stronger nucleophilic ability, because the alkyl group on the oxygen atom makes the bond angle smaller, which makes the lone pair of electrons react more dissimilarly with the electron-deficient system. Compound: 2-Ethylpyrazine, is researched, Molecular C6H8N2, CAS is 13925-00-3, about Characterization of Key Aroma Compounds in Beijing Roasted Duck by Gas Chromatography-Olfactometry-Mass Spectrometry, Odor-Activity Values, and Aroma-Recombination Experiments.COA of Formula: C6H8N2.

The dominant aroma compounds in the breast skin and breast muscle of Beijing roasted duck were investigated by gas chromatog.-olfactometry-mass spectrometry (GC-O-MS), odor-activity values, and aroma recombination. The results demonstrated that a total of 42 aroma compounds were identified in Beijing roasted duck, including aldehydes, ketones, alcs., acids, phenols, sulfur-containing compounds, and nitrogen-containing compounds Among the 42 aroma compounds, 18 were identified as important odorants with odor-activity values (OAVs) greater than 1. Aroma-recombination-omission experiments and sensory evaluation demonstrated that nine aroma compounds significantly contributed to the characteristic aroma of Beijing roasted duck. These nine key aroma compounds were 2-furfurylthiol, di-Me trisulfide, hexanal, heptanal, octanal, nonanal, methional, 1-octen-3-ol, and (E,E)-2,4-decadienal. Among these, 2-furfurylthiol (3620 ≤ OAV ≤ 31 606) and di-Me trisulfide (2515 ≤ OAV ≤ 23 470) significantly contributed to the aroma of roasted duck (p < 0.01). Sensory evaluation of the recombination model with the nine aroma compounds scored 4.5 out of 5 points. The major aroma profile of Beijing roasted duck included strong fatty, roasty, and meaty aromas. The key aroma compounds of Beijing roasted duck were concluded to be 2-furfurylthiol, di-Me trisulfide, hexanal, heptanal, octanal, nonanal, methional, 1-octen-3-ol, and (E,E)-2,4-decadienal. Although many compounds look similar to this compound(13925-00-3)COA of Formula: C6H8N2, numerous studies have shown that this compound(SMILES:CCC1=NC=CN=C1), has unique advantages. If you want to know more about similar compounds, you can read my other articles.

Reference:
Chiral Catalysts,
Chiral catalysts – SlideShare

Yasarawan, Nuttawisit; Thipyapong, Khajadpai; Ruangpornvisuti, Vithaya published an article about the compound: 4-Hydroxypicolinic acid( cas:22468-26-4,SMILESS:O=C(O)C1=NC=CC(O)=C1 ).Computed Properties of C6H5NO3. Aromatic heterocyclic compounds can be classified according to the number of heteroatoms or the size of the ring. The authors also want to convey more information about this compound (cas:22468-26-4) through the article.

Comparative study on kinetics and thermodn. of proton-related reactions of hydroxypicolinic acids was carried out using d. functional theory associated with polarizable continuum model of solvation. Mechanisms for such reactions were established. Both 3- and 4-hydroxypicolinic acid prefer zwitterionic forms to normal forms. For 6-hydroxypicolinic acid, keto forms are highly preferred. The pKa values and UV/visible bands predicted for some picolinic compounds agree with the experiment 5-Hydroxypicolinate shows the highest preference for complexation with copper(II) but 6-hydroxypolinate gives rise to the most stable complex. Kinetic stability of the trans-isomer relative to the cis-isomer of the complexes was evaluated. UV/visible spectral data predicted for some picolinate complexes are also in agreement with the previous experiment

Although many compounds look similar to this compound(22468-26-4)Computed Properties of C6H5NO3, numerous studies have shown that this compound(SMILES:O=C(O)C1=NC=CC(O)=C1), has unique advantages. If you want to know more about similar compounds, you can read my other articles.

Reference:
Chiral Catalysts,
Chiral catalysts – SlideShare