Tag: M.W=100-200

Synthetic Route of C5H5FN2. The fused heterocycle is formed by combining a benzene ring with a single heterocycle, or two or more single heterocycles. Compound: 5-Amino-2-fluoropyridine, is researched, Molecular C5H5FN2, CAS is 1827-27-6, about Amide-containing α-hydroxytropolones as inhibitors of hepatitis B virus replication. Author is Li, Qilan; Lomonosova, Elena; Donlin, Maureen J.; Cao, Feng; O’Dea, Austin; Milleson, Brienna; Berkowitz, Alex J.; Baucom, John-Charles; Stasiak, John P.; Schiavone, Daniel V.; Abdelmessih, Rudolf G.; Lyubimova, Anastasiya; Fraboni, Americo J.; Bejcek, Lauren P.; Villa, Juan A.; Gallicchio, Emilio; Murelli, Ryan P.; Tavis, John E..

The Hepatitis B Virus (HBV) RNase H (RNaseH) is a promising but unexploited drug target. Here, we synthesized and analyzed a library of 57 amide-containing α-hydroxytropolones (αHTs) as potential leads for HBV drug development. Fifty percent effective concentrations ranged from 0.31 to 54μM, with selectivity indexes in cell culture of up to 80. Activity against the HBV RNaseH was confirmed in semi-quant. enzymic assays with recombinant HBV RNaseH. The compounds were overall poorly active against human RNase H1, with 50% inhibitory concentrations of 5.1 to >1,000μM. The aHTs had modest activity against growth of the fungal pathogen Cryptococcus neoformans, but had very limited activity against growth of the Gram – bacterium Escherichia coli and the Gram + bacterium Staphylococcus aureus, indicating substantial selectivity for HBV. A mol. model of the HBV RNaseH templated against the Ty3 RNaseH was generated. Docking the compounds to the RNaseH revealed the anticipated binding pose with the divalent cation coordinating motif on the compounds chelating the two Mn++ ions modeled into the active site. These studies reveal that that amide aHTs can be strong, specific HBV inhibitors that merit further assessment toward becoming anti-HBV drugs.

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SDS of cas: 2150-55-2. So far, in addition to halogen atoms, other non-metallic atoms can become part of the aromatic heterocycle, and the target ring system is still aromatic. Compound: 2-Amino-4,5-dihydrothiazole-4-carboxylic acid, is researched, Molecular C4H6N2O2S, CAS is 2150-55-2, about Quantification of 2-aminothiazoline-4-carboxylic acid as a reliable marker of cyanide exposure using chemical derivatization followed by liquid chromatography-tandem mass spectrometry.

In this research, we have developed a novel and simple liquid chromatog. coupled with electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) method for quantification of 2-aminothiazoline-4-carboxylic acid (ATCA), which is produced by the direct reaction of cyanide (CN) with endogenous cystine. In forensic science, detection of CN is important because CN is a poison that is often used for murder or suicide, in addition to being produced by the thermal decomposition of natural or synthetic materials. However, because CN disappears rapidly from body tissue, ATCA is thought to be a more reliable indicator of CN exposure. For the method reported herein, human blood samples (20μL) were subjected to protein precipitation followed by derivatization with 4-bromoethyl-7-methoxycoumarin. Blood spiked with ATCA at concentrations ranging from 50 to 1500 ng/mL was used to prepare a calibration curve (lower limit of quantification; 50 ng/mL, lower limit of detection; 25 ng/mL). Our method uses chem. derivatization, so unlike previously reported methods, it does not require tedious pretreatment procedures, hydrophilic interaction liquid chromatog. columns, or specialized equipment. In addition, our method allows for repeatable and accurate quantification of ATCA, with intra- and inter-assay coefficients of variation of below 5.0% and below 6.0%, resp. We used the method to analyze ATCA in postmortem human blood samples, including samples from people who had intentionally ingested CN or were fire victims. Blood ATCA concentrations were higher among people who had ingested CN or were fire victims than among people in a control group (P < 0.0001). The data reported herein demonstrate that our LC/ESI-MS/MS method can be used to detect and quantify ATCA in postmortem blood samples and that CN exposure strongly affects ATCA concentration, providing a useful tool for detection of CN poisoning. From this literature《Quantification of 2-aminothiazoline-4-carboxylic acid as a reliable marker of cyanide exposure using chemical derivatization followed by liquid chromatography-tandem mass spectrometry》,we know some information about this compound(2150-55-2)SDS of cas: 2150-55-2, but this is not all information, there are many literatures related to this compound(2150-55-2).

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Pyrazine – Wikipedia,
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Related Products of 2150-55-2. 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-Amino-4,5-dihydrothiazole-4-carboxylic acid, is researched, Molecular C4H6N2O2S, CAS is 2150-55-2, about Identification of bioconversion product from DL-ATC and optimization of reaction conditions in Pseudomonas sp. F12. Author is Fan, Cui-li; Li, Zhi-min; Ye, Qin.

The objective if this work was to identify the bioconversion product from DL-2-amino-Δ2-thiazoline-4-carboxylic acid (DL-ATC) and enhance L-cysteine yield from it. Reaction mixture was analyzed by HPLC and LC-MS; comparison among different reaction conditions of L-cysteine decomposition was performed. Contrast to standard L-cysteine, the results of HPLC and LC-MS indicated that it was L-cysteine; a small amount of hydrogen sulfide produced from degradation of L-cysteine inhibited L-cysteine desulfhydrase dramaticly in air-free condition which contributed the highest amount of L-cysteine arrived 46.2 mmol/L with a yield of 94%, in contrast to that of 31.6% under initial condition. Pseudomonas sp. F12 equipped with the ability of converting DL-ATC to L-cysteine; it was beneficial for L-cysteine accumulation in air-free condition.

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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 2-Iminothiazolidine-4-carboxylic acid produces hippocampal CA1 lesions independent of seizure excitation and glutamate receptor activation, published in 1997, which mentions a compound: 2150-55-2, mainly applied to iminothiazolidinecarboxylate hippocampus CA1 lesion glutamate receptor, Electric Literature of C4H6N2O2S.

In this study, the ability of either 2-iminothiazolidine-4-carboxylic acid (2-ICA), glutamate, proline or NMDA (N-methyl-D-aspartate) injected i.c.v. to produce hippocampal lesions sensitive to glutamate antagonists was compared in mice. Hippocampal CA1 damage was observed 5-days following either a seizure (3.2 μmol) or subseizure (1.0 μmol) dose of 2-ICA. Glutamate (3.2 μmol) or proline (10 μmol) also produced hippocampal damage; glutamate damage was primarily to the CA1 subfield, whereas proline damaged neurons throughout the entire hippocampal formation. NMDA (3.2 nmol) caused seizure activity in all animals with a 50% lethality. No hippocampal damage was observed in surviving mice. Neither MK-801 (dizocilpine maleate) nor CNQX (6-cyano-7-nitroquinoxaline-2,3-dione) pretreatment prevented hippocampal lesions produced by 2-ICA. In contrast, MK-801 significantly reduced the frequency of mice displaying glutamate hippocampal lesions, but failed to block seizures produced by glutamate. MK-801 also protected neurons in the CA2-3 zone and the dentate gyrus, but not in the CA1 region of proline-injected mice. Finally, pretreatment with the mixed metabotropic glutamate receptor (mGluR)1/mGluR2 antagonist-agonist (S)-4-carboxy-3-hydroxyphenylglycine (CHPG) prevented hippocampal damage produced by the mGluR 1 agonist (RS)-3,5-dihydroxyphenylglycine (DHPG), but did not protect against 2-ICA hippocampal lesions. These results show that 2-ICA hippocampal CA1 damage is not mediated through ionotropic or metabotropic glutamate receptors. 2-ICA hippocampal damage may represent a neurotoxicity that is distinct from excitotoxic-mediated cell death.

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The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Kinetics of the cyanide-cystine reaction》. Authors are Gawron, Oscar; Fernando, Joseph.The article about the compound:2-Amino-4,5-dihydrothiazole-4-carboxylic acidcas:2150-55-2,SMILESS:O=C(C1N=C(N)SC1)O).Computed Properties of C4H6N2O2S. Through the article, more information about this compound (cas:2150-55-2) is conveyed.

The kinetics of the cystine-cyanide reaction was studied in 0.04M KOH at pH 12.5 by a spectrophotometric method. The reaction was bimol., with cyclization of the thiocyanato product much faster than the reverse reaction. Activation parameters at 35° were: Ea, 16.8 kcal./mole; ΔH*, 16.1 kcal./mole; and ΔS*, -7.4 e.u. The entropy of activation was about the same as that for the cyanide-S8 reaction but about 20 e.u. less than that for the cystine-SO3–reaction; this indicated the activated complex for cystine-SO3– is more crowded than that for cystine-CN-.

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The three-dimensional configuration of the ester heterocycle is basically the same as that of the carbocycle. Compound: 2-Amino-4,5-dihydrothiazole-4-carboxylic acid(SMILESS: O=C(C1N=C(N)SC1)O,cas:2150-55-2) is researched.Application In Synthesis of 2-Amino-4,5-dihydrothiazole-4-carboxylic acid. The article 《LC-MS/MS method development and validation for quantitative analyses of 2-aminothiazoline-4-carboxylic acid – a new cyanide exposure marker in post mortem blood》 in relation to this compound, is published in Talanta. Let’s take a look at the latest research on this compound (cas:2150-55-2).

2-Aminothiazoline-4-carboxylic acid (ATCA) is a hydrogen cyanide metabolite that has been found to be a reliable biomarker of cyanide poisoning, because of its long-term stability in biol. material. There are several methods of ATCA determination; however, they are restricted to extraction on mixed mode cation exchange sorbents. To date, there has been no reliable method of ATCA determination in whole blood, the most frequently used material in forensic anal. This novel method for ATCA determination in post mortem specimen includes protein precipitation, and derivatization of interfering compounds and their later extraction with Et acetate. ATCA was quant. analyzed via HPLC-tandem mass spectrometry with pos. electrospray ionization detection using a hydrophilic interaction liquid chromatog. column. The method satisfied all validation criteria and was tested on the real samples with satisfactory results. Therefore, this anal. approach has been proven to be a tool for measuring endogenous levels of ATCA in post mortem specimens. To conclude, a novel, accurate and sensitive method of ATCA determination in post mortem blood was developed. The establishment of the method provides new possibilities in the field of forensic science.

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Pyrazine – Wikipedia,
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Wang, Xinmou; Chen, Yuming; Song, Hongjian; Liu, Yuxiu; Wang, Qingmin published an article about the compound: Ethyl oxazole-5-carboxylate( cas:118994-89-1,SMILESS:O=C(C1=CN=CO1)OCC ).Name: Ethyl oxazole-5-carboxylate. 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:118994-89-1) through the article.

Although compounds with a 2-(2-arylphenyl) benzoxazole motif are biol. important, there are only a few methods for synthesizing them. Herein, authors report an efficient method for synthesis of such compounds by means of cobalt-catalyzed C-H/C-H cross-coupling reactions. This method has a broad substrate scope and good tolerance for sensitive functional groups. In addition, authors demonstrate that introducing a heteroarene moiety to biphenyl compounds enhanced their antifungal activity.

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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: 2150-55-2, is researched, SMILESS is O=C(C1N=C(N)SC1)O, Molecular C4H6N2O2SJournal, Article, ACS Omega called RECiQ: A Rapid and Easy Method for Determining Cyanide Intoxication by Cyanide and 2-Aminothiazoline-4-carboxylic Acid Quantification in the Human Blood Using Probe Electrospray Ionization Tandem Mass Spectrometry, Author is Hisatsune, Kazuaki; Murata, Tasuku; Ogata, Koretsugu; Hida, Minemasa; Ishii, Akira; Tsuchihashi, Hitoshi; Hayashi, Yumi; Zaitsu, Kei, the main research direction is forensic RECiQ ESIMSMS cyanide intoxication aminothiazolinecarboxylate blood biomarker.Application of 2150-55-2.

In this study, we developed a rapid and easy method to determine cyanide (CN) intoxication by quantification of CN and 2-aminothiazoline-4-carboxylic acid (ATCA), which is a new and reliable indicator of CN exposure, in the human blood using probe electrospray ionization tandem mass spectrometry (PESI/MS/MS) named RECiQ. For CN, we applied the previously reported one-pot derivatization method using 2,3-naphthalene-dialdehyde and taurine, which can directly derivatize CN in the blood. The anal. conditions of the CN derivatization were optimized as a 10 min reaction time at room temperature In contrast, ATCA could be directly detected in the blood by PESI/MS/MS. We developed quant. methods for the derivatized CN and ATCA using an internal standard method and validated them using quality control samples, demonstrating that the linearities of each calibration curve were greater than 0.995, and intra- and interday precisions and accuracies were 5.1-15 and 1.1-14%, resp. Moreover, the lower limit of detections for CN and ATCA were 42 and 43 ng/mL, resp. Finally, we applied RECiQ to three postmortem blood specimens obtained from victims of fire incidents, which resulted in the successful quantification of CN and ATCA in all samples. As PESI/MS/MS can be completed within 0.5 min, and the sample volume requirement of RECiQ is only 2μL of blood, these methods are useful not only for the rapid determination of CN exposure but also for the estimation of the CN intoxication levels during an autopsy.

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The preparation of ester heterocycles mostly uses heteroatoms as nucleophilic sites, which are achieved by intramolecular substitution or addition reactions. Compound: 5-Amino-2-fluoropyridine( cas:1827-27-6 ) is researched.Quality Control of 5-Amino-2-fluoropyridine.Panov, Maxim S.; Voskresenska, Valentyna D.; Ryazantsev, Mikhail N.; Tarnovsky, Alexander N.; Wilson, R. Marshall published the article 《5-Azido-2-aminopyridine, a New Nitrene/Nitrenium Ion Photoaffinity Labeling Agent That Exhibits Reversible Intersystem Crossing between Singlet and Triplet Nitrenes》 about this compound( cas:1827-27-6 ) in Journal of the American Chemical Society. Keywords: azidodiethylaminopyridine nitrene nitrenium ion photoaffinity labeling agent reversible intersystem. Let’s learn more about this compound (cas:1827-27-6).

The photochem. of a new photoaffinity labeling (PAL) agent, 5-azido-2-(N,N-diethylamino)-pyridine, was studied in aprotic and protic solvents using femtosecond-to-microsecond transient absorption and product anal., in conjunction with ab initio multiconfigurational and multireference quantum chem. calculations The excited singlet S1 state is spectroscopically dark, whereas photoexcitation to higher-lying singlet excited S2 and S3 states drives the photochem. reaction toward a barrierless ultrafast relaxation path via two conical intersections to S1, where N2 elimination leads to the formation of the closed-shell singlet nitrene. The singlet nitrene undergoes intersystem crossing (ISC) to the triplet nitrene in aprotic and protic solvents as well as protonation to form the nitrenium ion. The ISC rate constants in aprotic solvents increase with solvent polarity, displaying a “”direct”” gap effect, whereas an “”inverse”” gap effect is observed in protic solvents. Transient absorption actinometry experiments suggest that a solvent-dependent fraction from 20% to 50% of nitrenium ions is generated on a time scale of a few tens of picoseconds. The closed-shell singlet and triplet nitrene are separated by a small energy gap in protic solvents. As a result, the unreactive triplet state nitrene undergoes delayed, thermally activated reverse ISC to reform the reactive closed-shell singlet nitrene, which subsequently protonates, forming the remaining fraction of nitrenium ions. The product studies demonstrate that the resulting nitrenium ion stabilized by the electron-donating 4-amino group yields the final cross-linked product with high, almost quant. efficiency. The enhanced PAL function of this new azide with respect to the widely applied 4-amino-3-nitrophenyl azide is discussed.

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So far, in addition to halogen atoms, other non-metallic atoms can become part of the aromatic heterocycle, and the target ring system is still aromatic.Wang, Pu; He, Jun-Yao; Yin, Jiang-Feng researched the compound: 2-Amino-4,5-dihydrothiazole-4-carboxylic acid( cas:2150-55-2 ).Application In Synthesis of 2-Amino-4,5-dihydrothiazole-4-carboxylic acid.They published the article 《Enhanced biocatalytic production of L-cysteine by Pseudomonas sp. B-3 with in situ product removal using ion-exchange resin》 about this compound( cas:2150-55-2 ) in Bioprocess and Biosystems Engineering. Keywords: cysteine biocatalytic production Pseudomonas anion exchange resin. We’ll tell you more about this compound (cas:2150-55-2).

Bioconversion of DL-2-amino-Δ2-thiazoline-4-carboxylic acid (DL-ATC) catalyzed by whole cells of Pseudomonas sp. was successfully applied for the production of L-cysteine. It was found, however, like most whole-cell biocatalytic processes, the accumulated L-cysteine produced obvious inhibition to the activity of biocatalyst and reduced the yield. To improve L-cysteine productivity, an anion exchange-based in situ product removal (ISPR) approach was developed. Several anion-exchange resins were tested to select a suitable adsorbent used in the bioconversion of DL-ATC for the in situ removal of L-cysteine. The strong basic anion-exchange resin 201 × 7 exhibited the highest adsorption capacity for L-cysteine and low adsorption for DL-ATC, which is a favorable option. With in situ addition of 60 g L-1 resin 201 × 7, the product inhibition can be reduced significantly and 200 mmol L-1 of DL-ATC was converted to L-cysteine with 90.4 % of yield and 28.6 mmol L-1 h-1 of volumetric productivity. Compared to the bioconversion without the addition of resin, the volumetric productivity of L-cysteine was improved by 2.27-fold using ISPR method.

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Reference:
Pyrazine – Wikipedia,
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