Tag: M.W:100-200

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 Kynurenic acid and kynurenine aminotransferase are potential biomarkers of early neurological improvement after thrombolytic therapy: A pilot study., published in 2021, which mentions a compound: 492-27-3, Name is 4-Hydroxyquinoline-2-carboxylic Acid, Molecular C10H7NO3, Electric Literature of C10H7NO3.

BACKGROUND: Biomarkers for predicting treatment response to thrombolysis in acute ischemic stroke are currently lacking. Both, animal models and clinical studies have provided evidence that the kynurenine (KYN) pathway is activated in ischemic stroke. OBJECTIVES: In our pilot study, we aimed to investigate whether KYN pathway enzymes and metabolites could serve as potential biomarkers for treatment response in the hyperacute phase of ischemic stroke. MATERIAL AND METHODS: We included 48 acute ischemic stroke patients who received thrombolysis. Blood samples were taken both before and 12 h after treatment. Concentrations of 11 KYN metabolites were determined using ultra-high-performance liquid chromatography-mass spectrometry. To assess the treatment response, we used early neurological improvement (ENI), calculated as the difference between the admission and discharge National Institutes of Health Stroke Scale (NIHSS) scores. We performed receiver operating characteristic (ROC) analysis for KYN pathway metabolites and enzymes that showed a correlation with ENI. RESULTS: In the samples taken before thrombolysis, significantly lower concentrations of kynurenic acid (KYNA) and kynurenine aminotransferase (KAT) activity were found in patients who had ENI (p = 0.01 and p = 0.002, respectively). According to the ROC analysis, the optimal cut-off value to predict ENI for KYNA was 37.80 nM (sensitivity (SN) 69.2%, specificity (SP) 68.4%) and 0.0127 for KAT activity (SN 92.3%, SP 73.7%). CONCLUSIONS: Our research is the first clinical pilot study to analyze changes in the KYN pathway in ischemic stroke patients who received thrombolytic treatment. Based on our results, baseline KYNA concentration and KAT activity could serve as potential biomarkers to predict early treatment response to thrombolysis.

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Reference:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”

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: (S)-2-Bromosuccinic acid, is researched, Molecular C4H5BrO4, CAS is 20859-23-8, about The stereoselective total synthesis of (3R,5R)-sonnerlactone and (3R,5S)-sonnerlactone.Recommanded Product: (S)-2-Bromosuccinic acid.

The stereoselective synthesis of (3R,5R)-sonnerlactone (I) and (3R,5S)-sonnerlactone has been accomplished starting from l-aspartic acid. Our strategy involves asym. allylation, Alder-Rickert reaction and Mitsunobu macrolactonization as the key steps.

From this literature《The stereoselective total synthesis of (3R,5R)-sonnerlactone and (3R,5S)-sonnerlactone》,we know some information about this compound(20859-23-8)Recommanded Product: (S)-2-Bromosuccinic acid, but this is not all information, there are many literatures related to this compound(20859-23-8).

Reference:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”

Matencio, Adrian; Caldera, Fabrizio; Rubin Pedrazzo, Alberto; Khazaei Monfared, Yousef; K. Dhakar, Nilesh; Trotta, Francesco published the article 《A physicochemical, thermodynamical, structural and computational evaluation of kynurenic acid/cyclodextrin complexes》. Keywords: Kynurenic acid Cyclodextrin Inclusion complex Physicochem Stability; Cyclodextrin; Inclusion complex; Kynurenic acid; Physicochemical; Stability.They researched the compound: 4-Hydroxyquinoline-2-carboxylic Acid( cas:492-27-3 ).SDS of cas: 492-27-3. Aromatic heterocyclic compounds can be divided into two categories: single heterocyclic and fused heterocyclic. In addition, there is a lot of other information about this compound (cas:492-27-3) here.

In this work, the interaction between Kynurenic acid (KYNA) and several natural and modified cyclodextrins (CDs) is carried out. Among all the CD tested, HPβ-CD showed the strongest complexation constant (KF), with a value of 270.94 ± 29.80 M-1. Between natural (α- and β-) CDs, the complex of KYNA with β-CD was the most efficient. The inclusion complex of KYNA with CDs showed a strong influence of pH and temperature The KF value decreased at high pH values, when the pKa was passed. Moreover, an increase of the temperature caused a decrease in the KF values. The thermodn. parameters of the complexation (ΔH°, ΔS° and ΔG°) were studied with neg. entropy, enthalpy and spontaneity of the process at 25°C. Moreover, the inclusion complex was also characterized using FTIR and TGA. Finally, mol. docking calculations provided different interactions and their influence in the complexation constant

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Reference:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”

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: 20859-23-8, is researched, SMILESS is O=C(O)[C@@H](Br)CC(O)=O, Molecular C4H5BrO4Journal, Tetrahedron called Copper-catalyzed cross-coupling of amino acid-derived amides with (Z)-vinyl iodides: Unexpected solvent effect and preparation of plocabulin, Author is Wang, Leiming; Lei, Xinsheng; Wang, Quanrui; Li, Yingxia, the main research direction is peptide plocabulin synthesis microtubule destabilizer agent; amino acid amide copper catalyzed cross coupling vinyl iodide.Electric Literature of C4H5BrO4.

A copper-catalyzed cross-coupling reaction of amino acid-derived amides and (Z)-vinyl iodide was studied to improve a key step in the synthesis of plocabulin, a novel microtubule destabilizer agent of marine origin. The study revealed a profound solvent effect with 1,2-dimethoxyethane (DME), which gave consistently high yields across a large variety of the amide and (Z)-vinyl iodide substrates. The protocol was successfully utilized in the preparation of plocabulin and provided a significantly improved yield.

If you want to learn more about this compound((S)-2-Bromosuccinic acid)Electric Literature of C4H5BrO4, you may wish to communicate with the author of the article,or consult the relevant literature related to this compound(20859-23-8).

Reference:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”

Application of 20859-23-8. The protonation of heteroatoms in aromatic heterocycles can be divided into two categories: lone pairs of electrons are in the aromatic ring conjugated system; and lone pairs of electrons do not participate. Compound: (S)-2-Bromosuccinic acid, is researched, Molecular C4H5BrO4, CAS is 20859-23-8, about Thiomalate complexes of gold(I): preparation, characterization and crystal structures of 1:2 gold to thiomalate complexes. Author is Leblanc, Daren J.; Smith, Richard W.; Wang, Zhixian; Howard-Lock, Helen E.; Lock, Colin J. L..

The preparation and characterization of 1:2 gold to thiomalate complexes, as ammonium salts, is described. The crystal structures of both racemic and optically pure samples, (NH4)5[AuL2]·H2O [H3L = thiomalic acid, HO2CCH(SH)CH2CO2H] are described and compared. In each case, the gold atom is linearly coordinated to two ligand sulfur atoms. Bond lengths and angles are normal.

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Reference:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”

Recommanded Product: (S)-2-Bromosuccinic acid. The mechanism of aromatic electrophilic substitution of aromatic heterocycles is consistent with that of benzene. Compound: (S)-2-Bromosuccinic acid, is researched, Molecular C4H5BrO4, CAS is 20859-23-8, about Reaction of ammonia with optically active halogenated carboxylic acids supported on anion exchange resin. Author is Urata, Yoshikiyo.

The exchange degrees of Amberlyst A-26 (OH form) treated with L-α-chloro-(I) and L-α-bromosuccinic acid (II) were 70 and 58%, resp., dehydrobromination of II to fumaric acid was also observed L-Aspartic acid, prepared from I via the L-α-chlorosuccinate form of the resin by treatment with NH3-MeOH, aqueous NH3, liquid NH3, and NH3(g) was more optically active than the L-aspartic acid obtained by the direct treatment of I with NH3. The rearrangement during the substitution reaction of NH3 with the L-α-chlorosuccinate form of the resin occurred with configurational retention. The effect of the macro-mol. structure on this reaction was discussed.

There is still a lot of research devoted to this compound(SMILES：O=C(O)[C@@H](Br)CC(O)=O)Recommanded Product: (S)-2-Bromosuccinic acid, and with the development of science, more effects of this compound(20859-23-8) can be discovered.

Reference:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”

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 Influence of pH on radical reactions between kynurenic acid and amino acids tryptophan and tyrosine. Part II. Amino acids within the protein globule of lysozyme, published in 2021-10-31, which mentions a compound: 492-27-3, mainly applied to Back electron transfer; Cross-linking; Kynurenic acid; Lysozyme; Oxygenation; Protonation; Radicals; UV-A light, Computed Properties of C10H7NO3.

An acidosis, a decrease of pH within a living tissue, may alter yields of radical reactions if participating radicals undergo partial or complete protonation. One of photosensitizers found in the human eye lens, kynurenic acid (KNA-), possesses pKa 5.5 for its radical form that is close to physiol. pH 6.89 for a healthy lens. In this work we studied the influence of pH on mechanisms and products of photoinduced radical reactions between KNA- and amino acids tryptophan (Trp) and tyrosine (Tyr) within a globule of model protein, Hen White Egg Lysozyme (HEWL). Our results show that the rate constant of back electron transfer from kynurenyl to HEWL• radicals with the restoration of initial reagents – the major decay pathway for these radicals – does not change in the pH 3-7. The quantum yield of HEWL degradation is also pH independent, however a shift of pH from 7 to 5 completely changes the outcome of photoinduced damage to HEWL from intermol. crosslinking to oxygenation. HPLC-MS anal. has shown that four of six Trp and all Tyr residues of HEWL are modified in different extents at all pH, but the lowering of pH from 7 to 5 significantly changes the direction of main photodamage from Trp62 to Trp108 located at the entrance and bottom of enzymic center, resp. A decrease of intermol. cross-links via Trp62 is followed by an increase in quantities of intramol. cross-links Tyr20-Tyr23 and Tyr23-Tyr53. The obtained results point out the competence of crosslinking and oxygenation reactions for Trp and Tyr radicals within a protein globule and significant increase of oxygenation to the total damage of protein in the case of crosslinking deceleration by coulombic repulsion of pos. charged protein globules.

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Reference:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”

Related Products of 492-27-3. 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: 4-Hydroxyquinoline-2-carboxylic Acid, is researched, Molecular C10H7NO3, CAS is 492-27-3, about Circulating amino acids and amino acid-related metabolites and risk of breast cancer among predominantly premenopausal women.

Known modifiable risk factors account for a small fraction of premenopausal breast cancers. We investigated associations between pre-diagnostic circulating amino acid and amino acid-related metabolites (N = 207) and risk of breast cancer among predominantly premenopausal women of the Nurses′ Health Study II using conditional logistic regression (1057 cases, 1057 controls) and multivariable analyses evaluating all metabolites jointly. Eleven metabolites were associated with breast cancer risk (q-value < 0.2). Seven metabolites remained associated after adjustment for established risk factors (p-value < 0.05) and were selected by at least one multivariable modeling approach: higher levels of 2-aminohippuric acid, kynurenic acid, piperine (all three with q-value < 0.2), DMGV and phenylacetylglutamine were associated with lower breast cancer risk (e.g., piperine: ORadjusted (95%CI) = 0.84 (0.77-0.92)) while higher levels of creatine and C40:7 phosphatidylethanolamine (PE) plasmalogen were associated with increased breast cancer risk (e.g., C40:7 PE plasmalogen: ORadjusted (95%CI) = 1.11 (1.01-1.22)). Five amino acids and amino acid-related metabolites (2-aminohippuric acid, DMGV, kynurenic acid, phenylacetylglutamine, and piperine) were inversely associated, while one amino acid and a phospholipid (creatine and C40:7 PE plasmalogen) were pos. associated with breast cancer risk among predominately premenopausal women, independent of established breast cancer risk factors. There is still a lot of research devoted to this compound(SMILES：O=C(C1=NC2=CC=CC=C2C(O)=C1)O)Related Products of 492-27-3, and with the development of science, more effects of this compound(492-27-3) can be discovered.

Reference:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”

Electric Literature of C4H5BrO4. The protonation of heteroatoms in aromatic heterocycles can be divided into two categories: lone pairs of electrons are in the aromatic ring conjugated system; and lone pairs of electrons do not participate. Compound: (S)-2-Bromosuccinic acid, is researched, Molecular C4H5BrO4, CAS is 20859-23-8, about Optical resolution of (RS)-mercaptosuccinic acid and syntheses of four stereoisomers of 2-amino-3-[(1,2-dicarboxyethyl)sulfanyl]propanoic acid. Author is Shiraiwa, Tadashi; Ohkubo, Masanori; Kubo, Motoki; Miyazaki, Hideya; Takehata, Masaki; Izawa, Hisashi; Nakagawa, Kazuo; Kurokawa, Hidemoto.

To synthesize four stereoisomers of 2-amino-3-[(1,2-dicarboxyethyl)sulfanyl]propanoic acid (ADC), (RS)-mercaptosuccinic acid [(RS)-MSA] was optically resolved using (1S,2S)-2-amino-1-phenyl-1,3-propanediol and (R)- and (S)-1-phenylethylamine as resolving agents to yield (R)- and (S)-MSA with optical purities of 100%. In addition, the racemic structures of 1-propylammonium and 1-butylammonium salts of (RS)-MSA were examined based on m.p., solubility, IR spectra, and binary and ternary phase diagrams, with the aim of optical resolution by preferential crystallization of (RS)-MSA. Results indicated that the 1-butylammonium salt of (RS)-MSA [(RS)-BA salt] exists as a conglomerate and that the 1-propylammonium salt forms a racemic compound Optical resolution by preferential crystallization of (RS)-BA salt yielded (R)- and (S)-BA salts with optical purities of over 90%. The (R)- and (S)-MSA obtained by optical resolution were condensed with (R)- and (S)-2-amino-3-chloropropanoic acid hydrochlorides to give (2R,1’R)-, (2S,1’S)-, (2R,1’S)-, and (2S,1’R)-ADC. In addition, these stereoisomers were also synthesized from D- and L-cysteine and optically active bromosuccinic acid.

There is still a lot of research devoted to this compound(SMILES：O=C(O)[C@@H](Br)CC(O)=O)Electric Literature of C4H5BrO4, and with the development of science, more effects of this compound(20859-23-8) can be discovered.

Reference:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”

Application In Synthesis of 4-Hydroxyquinoline-2-carboxylic Acid. Aromatic compounds can be divided into two categories: single heterocycles and fused heterocycles. Compound: 4-Hydroxyquinoline-2-carboxylic Acid, is researched, Molecular C10H7NO3, CAS is 492-27-3, about Active components in Ephedra sinica stapf disrupt the interaction between ACE2 and SARS-CoV-2 RBD: Potent COVID-19 therapeutic agents. Author is Mei, Jie; Zhou, Yatong; Yang, Xinping; Zhang, Fan; Liu, Xiufeng; Yu, Boyang.

Ephedra sinica Stapf is a widely used folk medicine in Asia to treat lung diseases, such as cold, cough and asthma. Many efforts have revealed that some traditional Chinese medicine (TCM) prescriptions containing Ephedra sinica could effectively alleviate the symptoms and prevent the fatal deterioration of COVID-19. The present study aims to discover active compounds in Ephedra sinica disrupting the interaction between angiotensin-converting enzyme 2 (ACE2) and the SARS-CoV-2 spike protein receptor-binding domain (SARS-CoV-2 RBD) to inhibit SARS-CoV-2 virus infection. The ethanol extracts of Ephedra sinica were prepared Activity guided isolation of constituents was carried out by measuring the inhibitory activity on ACE2-RBD interaction. The structures of active compounds were identified by HPLC-Q-TOF-MS/MS and NMR. To testify the contribution of main components for the inhibitory activity, different samples were prepared by components knock-out strategy. The mechanism of compounds inhibiting protein-protein interaction (PPI) was explored by competition inhibition assays, surface plasmon resonance (SPR) assays and mol. docking. SARS-CoV-2 S protein-pseudoviruses were used to observe the viropexis effect in cells. Ephedra sinica extracts (ESE) could effectively inhibit the interaction between ACE2 and SARS-CoV-2 RBD (IC50 = 95.01μg/mL). Three active compounds, 4,6-dihydroxyquinoline-2-carboxylic acid, 4-hydroxyquinoline-2-carboxylic acid and 4-hydroxy-6-methoxyquinoline-2-carboxylic acid were identified to inhibit ACE2-RBD interaction (IC50 = 0.58μM, 0.07μM and 0.15μM resp.). And knock-out the three components could eliminate the inhibitory activity of ESE. Mol. docking calculations indicated that the hydrogen bond was the major intermol. force. Finally, our results also showed that these compounds could inhibit the infectivity of SARS-CoV-2 S protein-pseudoviruses to 293T-ACE2 (IC50 = 0.44-1.09μM) and Calu-3 cells. These findings suggested that quinoline-2-carboxylic acids in Ephedra sinica could be considered as potential therapeutic agents for COVID-19. Further, this study provided some justification for the ethnomedicinal use of Ephedra sinica for COVID-19.

There is still a lot of research devoted to this compound(SMILES：O=C(C1=NC2=CC=CC=C2C(O)=C1)O)Application In Synthesis of 4-Hydroxyquinoline-2-carboxylic Acid, and with the development of science, more effects of this compound(492-27-3) can be discovered.

Reference:
Copper catalysis in organic synthesis – NCBI,
Special Issue “Fundamentals and Applications of Copper-Based Catalysts”